Class 10

Punjab State Board PSEB 10th Class English Book Solutions English Main Course Book Chapter 5 Some Glimpses of Ancient Indian Thought and Practices Textbook Exercise Questions and Answers.

PSEB Solutions for Class 10 English Main Course Book Chapter 5 Some Glimpses of Ancient Indian Thought and Practices

Short Answer Type Questions

Question 1.
What caused desperation to the gods ?
Answer:
There was a fight between the demons and the gods. The demons seemed to have an upper hand. It caused desperation to the gods.

असुरों और देवताओं के बीच एक युद्ध हुआ। असुरों का पलड़ा भारी प्रतीत होता था। इससे देवताओं में निराशा पैदा हो गई।

Question 2.
Who did the gods go to in desperation ?
Answer:
The gods went to Lord Vishnu. They wanted to know the way to defeat the demons.

देवता भगवान् विष्णु के पास गए। वे असुरों को पराजित करने का तरीका जानना चाहते थे।

Question 3.
What was Lord Vishnu’s advice to the gods ?
Answer:
Lord Vishnu advised the gods to get a mighty sword prepared from the bones of some great sage.

भगवान् विष्णु ने देवताओं को सलाह दी कि वे एक शक्तिशाली तलवार प्राप्त करें जो किसी महान् सन्त की अस्थियों से बनी हो।

Question 4.
What was the sacrifice of Saint Dadhichi ?
Answer:
He laid down his life so that his bones could be made into an invincible weapon for the gods.

उसने अपने प्राणों का बलिदान कर दिया ताकि उसकी अस्थियों से देवताओं के लिए एक अपराजेय शस्त्र बनाया जा सके।

Question 5.
What is the real spirit behind the yajnas performed in our homes ?
Answer:
It is the spirit of charity, renunciation, sacrifice and detachment.

यह दान, त्याग, बलिदान और वैराग्य की भावना होती है।

Question 6.
What does the tradition of feeding birds and animals prove ?
Answer:
It proves that the people of our country believe in the unity and sanctity of all life.

इससे सिद्ध होता है कि हमारे देश के लोग सम्पूर्ण जीवन की एकता तथा पवित्रता में विश्वास रखते हैं।

Question 7.
Why did some scholars laugh at Ashtavakra ?
Answer:
Ashtavakra had a deformed body. He looked very ugly. Therefore, some scholars laughed at him.

अष्टवक्र का शरीर टेढ़ा-मेढ़ा था। वह बहुत कुरूप लगता था। इसलिए कुछ विद्वान उस पर हंस पड़े।

Question 8.
How did Ashtavakra react when some scholars laughed at him ?
Or
How did Ashtavakra react ?
Answer:
Ashtavakra became very angry. He called them skinners because they measured the worth of a person from his skin.

अष्टवक्र बहुत क्रोधित हो उठा। उसने उन्हें चर्मकार कहा क्योंकि वे किसी व्यक्ति का मूल्य उसकी चमड़ी से आंकते थे।

Question 9.
What did Vivekananda say to the lady who laughed at his ____ simple dress ?
Answer:
He said that it was the tailor who made a man in the lady’s country. But in his own country, it was the real worth and character of a person that mattered.

उसने कहा कि उस औरत के देश में एक दर्जी होता है जो किसी व्यक्ति को बनाता है। किन्तु उसके अपने देश में व्यक्ति का वास्तविक मूल्य और उसका चरित्र होता है जिसका महत्त्व होता है।

Question 10.
What was the status of women in ancient India ?
Answer:
In ancient India, women enjoyed a high status. No auspicious function was considered complete without their participation.

प्राचीन भारत में औरतों का दर्जा ऊंचा था। कोई भी शुभ कार्य उनकी भागीदारी के बिना पूरा नहीं माना जाता था।

Question 11.
Why did Shivaji bow his head before the woman who was brought to him as a gift ?
Answer:
Shivaji had great regard for women. He looked upon them as his mothers. That was why he called that woman mother and bowed his head before her.

शिवाजी औरतों के प्रति बहुत सम्मान रखते थे। वह उन्हें अपनी माताएं मानते थे। इसीलिए उन्होंने उस औरत को मां कहा और उसके सामने अपना सिर झुकाया।

Question 12.
Why, according to you, were the wars fought in the Mahabharata and Ramayana sacred ?
Answer:
These wars were fought to defend and uphold the honour of motherhood. That was why they were considered sacred.

ये युद्ध मातृत्व की रक्षा और उसे बनाए रखने के लिए लड़े गए थे। इसी कारण से वे पवित्र माने जाते थे।

Question 13.
What does Lord Rama’s meeting with a Bheel woman and eating the tasted berries show ?
Answer:
It shows that in ancient India, there was never any discrimination on the basis of caste, creed or profession.

इससे पता चलता है कि प्राचीन भारत में कभी भी जाति, नस्ल या व्यवसाय के आधार पर भेद-भाव नहीं होता था।

Long Answer Type Questions

Question 1.
Why, according to the author, should those people be ashamed of themselves who believe in female foeticide ?
Answer:
The author says that India is a land where women were always held in great regard. No auspicious ceremony was considered complete without their participation. The two great epics, the Ramayana and the Mahabharata, also uphold the honour of women. In such a country, the evil of female foeticide is indeed a matter to be ashamed of.

लेखक कहता है कि भारत एक ऐसा देश है जहां औरतों का सदा ही बहुत सम्मान किया जाता था। उनके शामिल हुए बिना कोई भी शुभ अनुष्ठान सम्पूर्ण नहीं माना जाता था। रामायण और महाभारत के दो महाकाव्य भी औरतों के सम्मान का समर्थन करते हैं। ऐसे देश में कन्या-भ्रूण हत्या वास्तव में ही एक शर्मिंदा होने की बात है।

Question 2.
How does the author support the idea of the victory of the good over the evil ?
Answer:
The author gives the examples of Dadhichi and Sri Guru Gobind Singh’s sons. These great souls sacrificed their lives for the cause of good. Dadhichi sacrificed his life to give the gods an invincible weapon against the asurs. The young sons of Sri Guru Gobind Singh sacrificed their lives for the sake of their faith and the principles of justice.

लेखक दधीचि और गुरु गोबिन्द सिंह के पुत्रों का उदाहरण देता है। इन महान आत्माओं ने अच्छाई की खातिर अपने जीवन बलिदान कर दिए। दधीचि ने असुरों के विरुद्ध देवताओं को एक अजेय शस्त्र प्रदान करने के लिए अपना जीवन बलिदान कर दिया। गुरु गोबिन्द सिंह के छोटे पुत्रों ने अपने धर्म और न्याय के सिद्धान्तों की खातिर अपने जीवन बलिदान कर दिए।

Question 3.
What is the basic difference between the position of women in society in the ancient times and now ?
Answer:
In the ancient times, women enjoyed a very high position. No auspicious ceremony was considered complete without their participation. They were never looked upon as objects of lust. Now women are not given their due regard. The incidents of dowry killings and female foeticide are matters of shame for us.

प्राचीन समय में औरतों को बहुत ऊंचा स्थान प्राप्त था। कोई भी शुभ अनुष्ठान औरतों की उपस्थिति के बिना पूरा नहीं माना जाता था। उन्हें कभी भी वासनापूर्ति की चीज़ नहीं माना जाता था। परन्तु अब औरतों को उचित सम्मान नहीं दिया जाता है। दहेज के कारण होने वाली मौतें और कन्या-भ्रूण की हत्या हमारे लिए लज्जा की बातें हैं।

Question 4.
What does the practice of langar’ stand for ? Explain.
Answer:
Langar is a symbol of love and fellow-feeling. It is a symbol of brotherhood and equality. It tells us that we should eat only after we have shared our meal with others. By sharing our meals with others, we develop a great feeling of love and brotherhood.

लंगर प्यार और सहभावना का प्रतीक है। यह भाईचारे और समानता का प्रतीक है। यह हमें बताता है कि हमें केवल तब खाना चाहिए जब हम दूसरों के साथ अपना भोजन बांट चुके हों। दूसरों के साथ अपना भोजन बांटने से हम प्यार और भाईचारे की महान भावनाओं को विकसित करते हैं।

Question 5.
Give an example to prove that in ancient India, there was no discrimination on the basis of caste.
Answer:
We find a great example of it in the Ramayana. Lord Rama ate the tasted berries from a Bheel woman. The woman was a shudra while Rama was a ksatriya. It shows that in ancient India, there was no discrimination on the basis of caste.

रामायण में हमें इसका एक महान उदाहरण मिलता है। भगवान राम ने एक भील औरत से जूठे बेर खाए थे। वह औरत एक शूद्र थी जब कि राम एक क्षत्रिय थे। इससे पता चलता है कि प्राचीन भारत में जाति के आधार पर कोई भेद-भाव नहीं था।

Vocabulary and Grammar

Objective Type Questions

Question 1.
Some scholars laughed at Ashtavakra’s ….
(i) joke
(ii) friend
(iii) luck
(iv) deformed body
Answer:
(iv) deformed body

Question 2.
In ancient India, the woman was always considered a goddess. (True /False)
Answer:
True

Question 3.
The gods went to Lord Vishnu in desperation. (True /False)
Answer:
True

Question 4.
Who was losing in the battle between the gods and the demons ?
Answer:
The gods

Question 5.
What did Saint Dadhichi advise the gods to make ?
(i) An arrow
(ii) A sword
(iii) Bones
(iv) None of these.
Answer:
(iv) None of these.

Question 6.
Shivaji bowed his head before the …………….
(i) man
(ii) woman
(iii) teacher
(iv) king
Answer:
(ii) woman

Answer each of the following in one word / phrase / sentence :

Question 1.
In the fight beween the demons and gods, who was winning initially ?
Answer:
The demons.

Question 2.
Who was Dadhichi ?
Answer:
He was a great saint.

Question 3.
What did Dadhichi give to gods ?
Answer:
He gave them all the bones of his body.

Question 4.
Who is the author of this chapter ?
Answer:
Dr. D.V. Jindal.

Question 5.
How did the young sons of Sri Guru Gobind Singh sacrifice their life?
Answer:
They chose to be bricked alive for the sake of their faith.

Question 6.
What does ‘Vasudhev Kutumbukam’ stand for?
Answer:
It stands for the entire universe is our family’.

Question 7.
Who was Ashtavakra ?
Answer:
He was a well-known sage.

Question 8.
Why were the gods depressed ?
Answer:
Because the demons seemed to be winning.

Question 9.
Why was Ashtavakra angry ?
Answer:
Because the scholars were laughing at his misshapen body.

Question 10.
What supreme quality of Chatrapati Shivaji has been highlighted in the chapter ?
Answer:
His quality of giving highest respect to women.

Complete the following:

1. The fight took place between gods and ………….
2. Dadhichi readily gave his …………… to gods.
3. The two sons of Sri Guru Gobind Singh were ………….
4. The elder ones treat it as their duty to feed ………….
5. The great sage, Ashtavakra, came to the court of ………….. have always been given high respect in India.
Answer:
1. demons
2. bones
3. bricked alive
4. the birds and animals
5. king Janaka
6. Women.

Write True or False against each statement :

1. The demons seemed to be losing the fight.
2. Gods went to Lord Brahma for advice.
3. Feeding birds shows our people’s belief in the unity of all life.
4. Ashtavakra was a very handsome sage.
5. Chhatrapati Shivaji was very respectable to women.
6. In Lord Rama’s time, there was no discrimination on the basis of cast or creed.
Answer:
1. False
2. False
3. True
4. False
5. True
6. True.

Choose the correct option for each of the following:

Question 1.
A long fight took place
(a) among demons themselve
(b) among gods
(c) between demons and gods
(d) none of the above.
Answer:
(c) between demons and gods

Question 2.
What was to be made from Sage Dadhichi’s bones ?
(a) A thunderbolt (Vajrapatt).
(b) A bow.
(c) A chakra.
(d) A spear.
Answer:
(a) A thunderbolt (Vajrapatt).

Question 3.
Indians feel happy to feed ……
(a) birds
(b) beasts
(c) animals
(d) both (a) and (c).
Answer:
(d) both (a) and (c).

Question 4.
In ancient India, women enjoyed ……….
(a) complete freedom
(b) a very high status
(c) all luxuries
(d) quarrels and fights.
Answer:
(b) a very high status

Some Glimpses of Ancient Indian Thought and Practices Summary & Translation in English

Some Glimpses of Ancient Indian Thought and Practices Introduction:
In this chapter, the author tells about the traditions and practices prevalent in ancient India. He says that our old philosophy teaches us the spirit of detachment. But now corruption, greed and lust for easy money have overshadowed this noble philosophy. Our old philosophy teaches us that the whole universe is one family. But now we have forgotten this philosophy. In ancient India, there was no discrimination on the basis of caste, creed or sex. But now such discrimination is quite prevalent. Women are not getting their rightful place in the society. The practice of female foeticide has become very common.

Some Glimpses of Ancient Indian Thought and Practices Summary & Translation in English

(Page 72)

In a fight between the demons’ and the gods once, the demons were having an Upper hand. In desperation and anxiety, the gods went to Lord Vishnu to find out as to how they could vanquish the demons. The Lord advised them to get a mighty sword (ah underbolt, Vajarpatt) prepared from he bones of some great sage. Accordingly; he gods approached the sage Dadhichi, great saint. Dadhichi took no time in laying down his life so that his bones could be made into an invincible weapon (amoghastra). This victory of the good over evil is the rarest of the rare examples of great renunciation and sacrifice that this culture teaches.

Who can forget the supreme sacrifice of the young sons of Sri Guru Gobind Singh ? They chose to be bricked alive for the sake of their faith and the canons of justice and true liberty. Our philosophy and thought teach us to renounce , to sacrifice, to give away in charity in the real spirit of detachment. ‘Idam naa mam’ (This does not belong to me) is the real spirit behind the yajnas we are called upon to perform frequently in our homes. Should corruption, greed and lust for easy money have any place in a country rich with such noble and lofty traditions ?

(Page 73)

The elder ones of this country, as per tradition coming down from thousands of years to this day, consider it a divine and blessed duty to feed the birds flying in the sky, the animals moving about on. this earth and the insects living in small holes inside the earth. This noble tradition is ocular proof of the fact that the people of this country believe in the unity of life, anywhere and everywhere.

‘Vasudhev Kutumbukam’, the entire Universe is one family, is the basic thought that works here and in the various such ceremonies like the tradition of ‘langar’ in the holy temples and Gurudwaras and the message of the holy Gurus contained in the directive: ‘Eat only after you have shared your meal with others, (Wand chakra).’ This idea of distribution applies not to food only; it extends well up to the entire resources and funds that are available to man. Do we still need to be taught to love the entire mankind as our kith and king and respect the sanctity of life through total non-violence

Once, the story goes, king Janaka of Maithil (present Bihar) called a meeting of the scholars to discuss some ticklish issue based on high philosophic thought. A well-known sage named Ashtavakra (so called – because of his deformed body) was also invited to this meeting. As Ashtavakara entered the portals of the palace hall and walked up the passage, some scholars already present there burst into a derisive laughter. How could such a deformed and misshapen person discuss high philosophy, they felt.

Ashtavakra thundered back to the king, “O King ! I feel ashamed of being invited to this assembly of skinners(persons who deal in animal skins; Charamkars). It is only a skinner who measures intelligence or status of a person from his skin or physical looks or the colour and shape of his skin or body.”

(Page 74)

This put the entire assembly to shame and brought them to their knees to beg pardon of this great saint. Colour of the skin or shape of the body has never been a measure of intelligence or status in this country. Lord Rama’s eating of the tasted berries from a Bheel woman (a Shudra woman who used to sprinkle water on the earth with the help of a leather bag) is a sufficient proof of the fact that there was never any discrimination on the basis of caste, creed or profession of a person in ancient India. One is here also reminded of what the enlightened sage, Swami Vivekananda, said to a lady in America who laughed at his ‘simple’ dress : “Madam, in your country, it is the tailor who makes a man; in my country it is the intrinsic worth and character of a person that make him or her great.”

Isn’t it unwise to support, tacitly or otherwise, any talk of such discrimination on such frivolous bases today ? The history of this great land is full of examples where no auspicious function was considered to be held properly without the participation of women. So much so, that if no woman could somehow make it to the function, a statue of the woman was created to mark her auspicious presence. This only proves that a woman in this great land was never looked upon as an object of lust or sex; she was always considered a devi (goddess), Kanjak (a young, unmarried girl child fit to be worshipped), the mother of mankind, the ardhangini, the inseparable but equal wheel of the rat ha (chariot) of life.

(Page 75)

This fitly explains Chhatrapati Shivaji’s bowing his head before a woman and respectfully restoring her dignity Shivaji’s bowing his head before a woman and respectfully restoringid her dignity as a mother when some misguided soldiers of his victorious army presented her to Shivaji as gift. This too explains that the great wars in both the sacred epics, the Ramayana and the Mahabharata, were fought for defending and upholding the honour of this matrishakti, the powerful motherhood. Does this not put those to shame who think of resorting to female foeticide or denying the female sex their rightful place in the affairs of the world ?

Some Glimpses of Ancient Indian Thought and Practices Summary & Translation in Hindi

Some Glimpses of Ancient Indian Thought and Practices Introduction:
इस पाठ में लेखक प्राचीन भारत में प्रचलित परम्पराओं और रिवाजों के बारे में बताता है। वह कहता है कि हमारा प्राचीन दर्शन हमें विराग की भावना सिखाता है। परन्तु अब भ्रष्टाचार, लालच और लालसा ने इस उत्तम दर्शन को ढक लिया है। हमारा प्राचीन दर्शन हमें सिखाता है कि पूरा ब्रह्माण्ड एक परिवार है। परन्तु अब हम इस दर्शन को भूल चुके हैं। प्राचीन भारत में जाति, धर्म या लिंग के आधार पर कोई भेदभाव नहीं होता था। परन्तु अब इस प्रकार का भेदभाव बहुत आम है। औरतों को समाज में उनका उचित स्थान नहीं मिल रहा। कन्या-भ्रूण हत्या एक आम बात हो चुकी है।

Some Glimpses of Ancient Indian Thought and Practices Summary & Translation in Hindi

(Page 72)

असुरों और देवताओं के मध्य युद्ध के दौरान एक बार असुरों का पलड़ा भारी हो रहा था। निराशा और चिंता से भर कर देवतागण भगवान् विष्णु के पास यह जानने के लिए गए कि वे किस प्रकार असुरों को हरा सकते थे। भगवान् ने उन्हें सलाह दी कि वे किसी महान् सन्त की हड्डियों से तैयार की गई एक शक्तिशाली तलवार (वज्रपात) प्राप्त करें। इसी उद्देश्य से देवतागण सन्त दधीचि के पास पहुँचे जो एक महान् सन्त था। दधीचि ने अपने प्राणों का बलिदान करने में कोई देर न की ताकि उसकी हड्डियों से एक अजेय शस्त्र (अमोघास्त्र)

बनाया जा सके। बुराई के ऊपर अच्छाई की यह विजय महान् त्याग और बलिदान के उन दुर्लभतम् उदाहरणों में से एक है जो यह संस्कति सिखाती है। श्री गुरु गोबिन्द सिंह के छोटे-छोटे पुत्रों के महानतम् बलिदान को कौन भूल सकता है ? उन्होंने स्वेच्छा से अपने धर्म, न्याय के आदर्शों तथा वास्तविक स्वतन्त्रता के लिए स्वयं को ईंटों में चिनवा लिया। हमारा दर्शन और हमारे विचार हमें त्याग करना, बलिदान करना, वैराग्य की सच्ची भावना के साथ अपना सर्वस्व दान में दे देना सिखाते हैं। ‘इदम् न माम’ (यह मेरी नहीं है) ही वह वास्तविक भावना है जो उन यज्ञों में निहित होती है जिन्हें हमें अपने घरों में विभिन्न अवसरों पर प्रायः आयोजित करने को कहा जाता है। क्या भ्रष्टाचार, लालच और किसी भी तरीके से धन कमाने की लालसा का कोई स्थान ऐसे देश में होना चाहिए जो ऐसी श्रेष्ठ तथा उच्च परम्पराओं से समृद्ध हो ?

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इस देश के बुजुर्ग व्यक्ति, हजारों वर्षों से आज तक चली आ रही परम्परा के अनुसार, इसे अपना दैवी और पवित्र कर्त्तव्य मानते हैं कि वे आकाश में उडते हए पक्षियों. इस धरती पर विचरने वाले पशओं तथा धरती के अन्दर अपने छोटे-छोटे. बिलों में रहने वाले कीड़े मकौड़ों के लिए खाने को दें। यह उत्तम परम्परा इस तथ्य का प्रत्यक्ष प्रमाण है कि इस देश के लोग किसी भी जगह और हर जगह जीवन की एकता में विश्वास रखते ‘वसुधैव कुटुम्बकम्’ (पूरा विश्व एक परिवार है) वह मूल विचार है जो यहां काम करता है, और उन विभिन्न अनष्ठानों में भी जैसे कि पवित्र मंदिरों और गुरुद्वारों में लंगर की परम्परा, तथा महान् गुरुओं के उस संदेश में जो इस निर्देश में निहित है कि: ‘भोजन तभी’

करो जब तुमने अपना भोजन अन्य व्यक्तियों के साथ बाँट लिया हो (वंड छको)।’ बांटने का यह विचार केवल भोजन पर ही लागू नहीं होता, यह उन सभी स्रोतों तथा निधियों पर भी लागू होता है जो मनुष्य को प्राप्त हैं। क्या अभी भी हमें यह सिखाए जाने की आवश्यकता है कि हम सम्पूर्ण मानवता को अपना सम्बन्धी समझें और सम्पूर्ण अहिंसा के माध्यम से जीवन की पवित्रता का सम्मान करें ?
ऐसी कहानी है कि एक बार मैथिल (आज का बिहार) के राजा जनक ने किसी जटिल समस्या पर, जो उच्च दार्शनिक विचारों पर आधारित थी, विचार-विमर्श करने के लिए एक सभा बुलाई। अष्टवक्र नाम के एक प्रसिद्ध ऋषि को भी उस सभा में निमन्त्रित किया गया था।

(उसका नाम उसके शरीर की अंग-विकृति के कारण ऐसा पड़ गया था।) जैसे ही अष्टवक्र ने महल के सभा-भवन में प्रवेश किया और गलियारे में चल कर आने लगा, वहां पहले से उपस्थित कुछ विद्वान उपहास भरे ठहाके लगाने लगे। ऐसा अंग-विकृत तथा कुरूप व्यक्ति किस प्रकार उच्च दर्शन के विषय में चर्चा कर सकता था. उन्होंने ऐसा सोचा। इस पर अष्टवक्र ने गरजती हुई आवाज़ में राजा से कहा, “हे राजन ! चर्मकारों (पशु-चमड़ी का व्यापार करने वाले लोगों) की इस सभा में निमन्त्रित किए जाने पर मुझे लज्जा आ रही है। यह केवल एक चर्मकार ही होता है जो किसी व्यक्ति की बुद्धिमत्ता अथवा उसके पद का माप उसकी त्वचा तथा उसकी शारीरिक आकृति या उसकी त्वचा अथवा शरीर के रंग और आकृति से करता है।

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इस पर पुरी सभा लज्जित हो गई और वे उस महान् ऋषि से क्षमा मांगने के लिए अपने घुटनों के बल हो गए। त्वचा का रंग या शरीर की आकृति इस देश में कभी भी बुद्धिमत्ता अथवा ऊंचे पद का मापदंड नहीं रहे हैं।

भगवान् राम द्वारा एक भीलनी (एक शूद्र स्त्री जो चर्म मशक द्वारा ज़मीन पर पानी छिड़का करती थी) के जूठे बेरों को खाना इस तथ्य का पर्याप्त प्रमाण है कि प्राचीन भारत में जाति, धर्म अथवा व्यवसाय के आधार पर कभी भी किसी व्यक्ति से कोई भेद-भाव नहीं किया जाता था। यहां उस बात की भी याद आ जाती है जो उस प्रबुद्ध सन्त, स्वामी विवेकानन्द, ने अमरीका की उस स्त्री से कही थी जिसने उसके अत्यन्त सादे वस्त्रों का मज़ाक उड़ाया था, “मैडम, आपके देश में किसी व्यक्ति को एक दर्जी बनाता है; मेरे देश में किसी व्यक्ति के आंतरिक गुण और उसका चरित्र होते हैं जो उसे महान् बनाते हैं।”

क्या यह मूर्खता नहीं होगी कि प्रत्यक्ष या अप्रत्यक्ष रूप से ऐसे महत्त्वहीन आधारों पर इस तरह के भेद-भाव वाली किसी चर्चा का आजकल अनुमोदन किया जाए? इस महान् देश का इतिहास ऐसे उदाहरणों से भरा पड़ा है जहां स्त्रियों द्वारा भाग लिए बिना कोई भी शुभ कार्य उचित रूप से आयोजित नहीं समझा जाता था। यहां तक कि यदि कोई स्त्री किसी कारण से उस कार्य में सम्मिलित नहीं हो पाती थी तो उसकी शुभ उपस्थिति के प्रतीक के रूप में उस स्त्री की मूर्ति बनवाई जाती थी। इससे केवल यही सिद्ध होता है कि इस महान् देश में स्त्री को वासना या कामेच्छा पूरी करने वाली चीज़ कभी नहीं समझा जाता था; उसे सदा एक देवी, एक कंजक (एक छोटी उम्र की अविवाहित कन्या जिसकी पूजा की जानी चाहिए), मानव-मात्र की मां, अर्धांगिनी, जीवन रथ का अभिन्न किन्तु बराबरी वाला पहिया माना जाता था।

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छत्रपति शिवाजी द्वारा एक स्त्री के सामने सिर झुकाने और एक मां की तरह उसकी प्रतिष्ठा को पुनः स्थापित करने के पीछे यही भावना काम कर रही थी जब उनकी विजयी सेना के कुछ पथभ्रष्ट सैनिकों ने उस स्त्री को शिवाजी के सामने एक उपहार के रूप में प्रस्तुत किया। यह हमें यह भी बताता है कि दोनों पवित्र महाकाव्यों, रामायण और महाभारत, में महायुद्ध इसी मातृशक्ति के सम्मान की रक्षा के लिए और उसे बनाए रखने के लिए लड़े गए थे। क्या यह बात उन लोगों को लज्जा से नहीं भर देती जो कन्या-भ्रूण हत्या की बात सोचते हैं अथवा विश्व के मामलों में स्त्रियों को उनका न्याय-संगत स्थान नहीं देते हैं ?

Punjab State Board PSEB 10th Class English Book Solutions English Main Course Book Chapter 4 A Gift for Christmas Textbook Exercise Questions and Answers.

PSEB Solutions for Class 10 English Main Course Book Chapter 4 A Gift for Christmas

Short Answer Type Questions

Question 1.
Why was Della crying ?
Answer:
Della wanted to buy a Christmas gift for Jim, but she didn’t have money for it. So she was crying.

डैला जिम के लिए एक क्रिसमस उपहार खरीदना चाहती थी, किन्तु उसके पास इसके लिए पैसे नहीं थे। इसलिए वह रो रही थी।

Question 2.
Describe the poverty of Della’s house.
Answer:
Signs of poverty were everywhere in the house. She had only a little couch. It was also very very dirty.

घर में सब जगह निर्धनता के चिन्ह थे। उसके पास केवल एक छोटा-सा सोफा था। यह भी बहुत गन्दा था।

Question 3.
What type of present had Deila planned for Jim ?
Answer:
Della wanted to buy a fine present for Jim. She wanted it to be something rare which Jim could feel proud of.

डैला जिम के लिए कोई सुन्दर उपहार खरीदना चाहती थी। वह कोई ऐसी चीज़ चाहती थी जो दुर्लभ हो और जिस पर जिम गर्व महसूस कर सके।

Question 4.
What were the two prized possessions of Jim and Della ?
Answer:
Jim had a golden watch. Before him, it had been his father’s and grandfather’s. Della had lovely brown hair that reached below her knees.

जिम के पास एक सुनहरी घड़ी थी। उससे पहले यह उसके पिता की और उसके दादा की रही थी। डैला के पास भूरे रंग के सुन्दर बाल थे जो उसके घुटनों के नीचे तक पहुंचते थे।

Question 5.
Describe the present Della bought for Jim.
Answer:
Della bought a platinum watch-chain for Jim. It was simple but well made.

डैला ने जिम के लिए प्लैटिनम की बनी घड़ी की एक चेन खरीदी। यह सादी किन्तु अच्छी बनी हुई लगती थी।

Question 6.
How did Della manage to buy the gift ?
Answer:
Della had beautiful long hair. She sold it for twenty dollars. Thus she was able to buy a Christmas gift for Jim.

डैला के बाल लम्बे और सुन्दर थे। उसने इन्हें बीस डॉलर में बेच दिया। इस प्रकार वह जिम के लिए एक क्रिसमस उपहार खरीदने के योग्य हो गई।

Question 7.
What did Della think when she looked at herself in the mirror ?
Answer:
Della looked at herself in the mirror. She looked like a boy. She became very nervous. She thought Jim would be very angry with her.

डैला ने खुद को आइने में देखा। वह एक लड़के के जैसी लगती थी। वह बहुत घबरा गई। उसने सोचा जिम उससे बहुत नाराज़ होगा।

Question 8.
What was Jim’s reaction on seeing Della’s hair gone ?
Answer:
There was a strange expression in Jim’s eyes. It was not anger or surprise.
It was not disapproval also. He simply stared at her fixedly.

जिम की आँखों में एक विचित्र भाव था। यह न तो गुस्सा था, और न ही हैरानी। यह न पसन्द करने का भाव भी नहीं था। वह केवल उसे एकटक घूरता रहा।

Question 9.
What explanation did Delle give to Jim ?
Answer:
Della said that she wanted to buy a Christmas present for Jim, but she had not the money. So she had to sell her hair to get the money.

डैला ने कहा कि वह जिम के लिए क्रिसमस का कोई उपहार खरीदना चाहती थी किन्तु उसके पास पैसे नहीं थे। इसलिए उसे पैसे प्राप्त करने के लिए अपने बाल बेचने पड़े।

Question 10.
What was in the package that Jim had brought for Della ?
Answer:
The package contained a beautiful set of combs. Della had seen them in a shop window. She had liked them but had never hoped she could get them.

पैकेट में कंघियों का एक सुन्दर जोड़ा था। डैला ने इन्हें एक दुकान की खिड़की में देखा था। उसे ये पसन्द थीं किन्तु उसे कभी आशा नहीं थी कि वह उन्हें प्राप्त कर सकेगी।

Question 11.
How did Jim manage to buy the present for Della ?
Answer:
Jim had a beautiful gold watch. He sold it to buy a present for Della.

जिम के पास एक सुन्दर सुनहरी घड़ी थी। डैला के लिए उपहार खरीद पाने के लिए उसने इसे बेच दिया।

Long Answer Type Questions

Question 1.
‘Expenses had been greater than she had calculated.’ Why ?
Answer:
Jim earned only twenty dollars a week. Out of it, eight dollars went for the house rent. Thus only twelve dollars were left for the family to live on. With all her parsimony, Della could save only 1.87 dollars. Naturally, the expenses had been greater than expected.

जिम सप्ताह में केवल बीस डॉलर कमाता था। इसमें से आठ डालर घर के किराए के लिए निकल जाते थे। इस प्रकार परिवार के निर्वाह के लिए केवल बारह डालर बच पाते थे। अपनी पूरी किफ़ायत के बावजूद डैला केवल 1.87 डालर बचा पाई थी। स्वाभाविक रूप से खर्चे आशा से अधिक रहे थे।

Question 2.
Describe in your own words the incident of Della’s selling her hair.
Answer:
Della wanted to buy a nice Christmas present for Jim, but she had not the money for it. She thought of selling her beautiful brown hair. She went to a shop that dealt in hair goods. There she sold her hair for twenty dollars. She at once took the money and ran to the market to buy a present for Jim.

डैला जिम के लिए क्रिसमस का एक सुन्दर उपहार खरीदना चाहती थी, किन्तु उसके पास इसके लिए पैसे नहीं थे। उसने अपने सुन्दर भूरे बाल बेचने का मन बनाया। वह एक दुकान पर गई जहां बालों की बनी चीजें बेची जाती थीं। वहां उसने अपने बाल बीस डालर में बेच दिए। उसने तुरन्त पैसे लिए और जिम के लिए उपहार खरीदने बाज़ार की तरफ़ दौड़ पड़ी।

Question 3.
Why was Della pleased with her selection of the present for Jim ?
Answer:
Jim had a gold watch of which he was very proud. Della bought a platinum chain for Jim’s watch. She wanted to give it to him as a Christmas present. The platinum chain was simple but well made. Della felt that it had been made for Jim and no one else. She was certain that Jim would be very pleased to have it.

जिम के पास सोने की एक घड़ी थी जिस पर उसे बहुत गर्व था। डैला ने जिम की घड़ी के लिए प्लैटिनम की एक चेन खरीदी। वह उसे यह क्रिसमस उपहार के रूप में देना चाहती थी। प्लैटिनम चैन सादी थी किन्तु बढ़िया बनी हुई थी। डैला को महसूस हुआ कि वह जिम के लिए बनी थी, तथा और किसी के लिए नहीं। उसे विश्वास था कि उसे प्राप्त करके जिम बहुत प्रसन्न होगा।

Question 4.
Why does the story writer call Jim ‘a poor fellow’ ?
Answer:
Jim was only twenty-two and he was burdened with a family. He earned only twenty dollars a week. Out of it, eight dollars went for the house rent. Thus very little was left to run the house. Jim had no overcoat or gloves. He looked very thin and serious. That is why the story writer calls him ‘a poor fellow’.

जिम की आयु केवल बाईस वर्ष की थी और वह एक परिवार के बोझ तले दबा हुआ था। वह सप्ताह में केवल बीस डालर कमाता था। इसमें से आठ डालर मकान के किराए में चले जाते थे। इस प्रकार घर चलाने के लिए बहुत थोड़े पैसे बचते थे। जिम के पास कोई ओवरकोट या दस्ताने नहीं थे। वह बहुत दुबला-पतला और गम्भीर दिखाई देता था। इसी कारण कहानी-लेखक उसे ‘बेचारा आदमी’ कहता है।

Question 5.
What do you think about the expression in Jim’s eyes ? Was it shock, surprise or anger ? Why ?
Answer:
When Jim looked at Della without her hair, a strange expression came in his eyes. It was not anger or surprise. It was not disapproval also. He simply stared at her fixedly. He had brought for her a costly pair of combs, but now he saw that she had no hair to wear them. It was this fact that had turned him blank.

जब जिम ने डैला को उसके बालों के बिना देखा तो उसकी आंखों में एक अजीब-सा भाव आ गया। यह कोई क्रोध या हैरानी का भाव नहीं था। यह पसन्द न आने का भाव भी नहीं था। वह केवल एकटक नज़र से उसे देखता रहा। वह उसके लिए कंघियों का एक कीमती जोड़ा लेकर आया था किन्तु अब उसने देखा कि उन्हें पहनने के लिए उसके कोई बाल नहीं थे। यही बात थी जिसने उसे भावशून्य बना
दिया था।

Question 6.
Both Jim and Della gave each other the gifts of rare love. How ? Explain.
Answer:
Jim and Della had two precious things. One was Della’s lovely long hair and the other was Jim’s gold watch. Della sold her hair to buy a Christmas present for Jim. And Jim sold his gold watch to buy a set of combs for Della’s hair. Thus their gift proved of no use for each other. Still they were the gifts of rare love. They showed how deeply the two loved each other.

जिम और डैला के पास दो कीमती चीजें थीं। एक थी – डैला के सुन्दर लम्बे बाल और दूसरी थी – जिम की सुनहरी घड़ी। डैला ने जिम के लिए एक क्रिस्मस उपहार खरीदने के लिए अपने बाल बेच दिए तथा जिम ने डैला के बालों के लिए कंघियों का एक जोड़ा खरीद पाने के लिए अपनी सोने की घड़ी बेच दी। इस प्रकार उनके उपहार एक-दूसरे के लिए किसी काम के न सिद्ध हुए। फिर भी वे दुर्लभ प्यार के उपहार थे। उनसे पता चलता था कि वे एक-दूसरे से कितना गहरा प्यार करते थे।

Vocabulary and Grammar

Question 1.
Supply suitable gerunds in the blanks :
Answer:
1. becoming
2. sleeping
3. climbing
4. pruning
5. annoying
6. living
7. putting
8. swimming
9. working
10. doing.

Question 2.
(a) Combine the nouns with gerunds in the table to form meaningful compound. nouns :
Answer:
1. fruit-picking
2. lorry-driving
3. birdwatching
4. coal-mining
5. weightlifting
6. fish-farming.

(b) Now combine the gerunds with the nouns to form compound nouns :
Answer:
1. waiting room
2. diving board
3. driving licence
4. dining hall
5. swimming pool
6. housing committee
7. skating rink.

Question 3.
Fill in the blanks with the suitable word :
Answer:
1. weakness
2. shout
3. sweet
4. timid
5. foal
6. keys
7. bleat
8. shame
9. deer
10. definite.

Question 4.
Fill in the blanks with the phrases given below :
Answer:
1. look after
2. look ahead
3. look out
4. took up
5. Put on
6. Put out
7. put off
8. put forward.

Question 5.
Correct the following sentences :
Answer:
1. To save the child, he jumped into the well.
2. You have to answer for your misbehaviour.
3. He did not agree to my proposal.
4. We should abide by the decision of the management.
5. He has been accused of theft.
6. You must apologize to the boss for your misbehaviour.
7. The student assured the teacher of his honesty.
8. Della was absorbed in her studies.
9. The nurse is attending on your father.
10. He is addicted to drugs.

Question 6.
Rewrite the following in the Indirect form of Narration
Answer:
1. Speaking with difficulty, Jim asked Della if she had cut off her hair.
Della replied that she had cut it off and sold it. She asked Jim if he didn’t like her just as well, without her hair.
2. Della told Jim that he didn’t have to look for it. She urged Jim to be good to her because she had done it all for him.
3. Della asked Jim if it wasn’t lovely. She added that she had hunted all over the town to find it and Jim would have to look at his watch a hundred times a day then. She asked Jim to give her his watch as she wanted to see how it (the chain) looked on it.

Objective Type Questions

Question 1.
The signs of richness were everywhere in their house. (True/False)
Answer:
False

Question 2.
What did Della buy for Jim as a Christmas gift ?
(i) Jeans
(ii) Set of combs
(iii) Watch
(iv) Watch-chain.
Answer:
(iv) Watch-chain.

Question 3.
The proud possession of Jim was …
(i) salary
(ii) Della
(iii) gold watch
(iv) flat.
Answer:
(iii) gold watch

Question 4.
Who did not have enough money to buy a Christmas present ?
(i) Jim
(ii) Della
(iii) Both of them
(iv) None of them.
Answer:
(iii) Both of them

Question 5.
Della sold her hair for ……………. dollars.
Answer:
twenty

Question 6.
What did Jim buy for Della as a Christmas gift?
(i) Jeans
(ii) Set of combs
(iii) Watch
(iv) Watch-chain.
Answer:
(ii) Set of combs

Answer each of the following in one word / phrase / sentence :

Question 1.
Who is the author of the story, ‘A Gift for Christmas’?
Answer:
O’ Henry.

Question 2.
How much money had Della saved ?
Answer:
One dollar and eighty-seven cents.

Question 3.
Why had Della been saving money ?
Answer:
She wanted to give a Christmas gift to her husband.

Question 4.
Did Della feel happy in her home ?
Answer:
No, she felt unhappy with her modest home.

Question 5.
What was Della’s ambition ?
Answer:
She wanted to live a rich person’s life.

Question 6.
What were the two precious possessions of Della and Jim ?
Answer:
Della’s beautiful hair and Jim’s ancestral gold watch.

Question 7.
How much did Della get in exchange for her hair ?
Answer:
Twenty dollars.

Question 8.
What did Jim need badly?
Answer:
A new overcoat and a pair of gloves.

Question 9.
How did Della look with her cropped hair ?
Answer:
She looked like a schoolboy.

Question 10.
What did Jim buy for Della ?
Answer:
A beautiful set of combs for her hair.

Complete the following :

1. Della wanted to buy a …………………. for Jim.
2. Della got twenty …………………. in exchange for her hair.
3. The two proud possessions in Youngs’ home were and ……………
4. Jim was ………………. to see Della with cropped hair.
5. Jim needed a …………………. and a pair of …………..
6. Jim sold his ………………. to buy a gift for Della.
Answer:
1. Christmas gift
2. dollars
3. Della’s hair, Jim’s gold watch
4. speechless
5. new overcoat, gloves
6. gold watch.

Write True or False against each statement :

1. Della’s household showed their poverty.
2. Della was accustomed to dreaming big.
3. Della sold her hair to buy a set of combs.
4. Jim hated Della with her short hair.
5. The gifts proved very useful to both of them.
6. Jim and Della’s love increased on receiving those ‘useless’ gifts.
7. Della bought a platinum watch-chain for Jim.
Answer:
1. True
2. True
3. False
4. False
5. False
6. True
7. True.

Choose the correct option for each of the following :

Question 1.
Della was crying because ………
(a) she had lost her purse
(b) she did not love Jim
(c) she had no money for a gift
(d) she had a terrible headache.
Answer:
(c) she had no money for a gift

Question 2.
The inside of Della’s home showed …………
(a) their poverty
(b) their good taste
(c) cracks in walls
(d) a lot of furniture.
Answer:
(a) their poverty

Question 3.
At the young age of twenty-two, Jim was burdened with ………
(a) a joint family
(b) a big responsibility
(c) heavy debt
(d) a family.
Answer:
(d) a family.

Question 4.
The ‘useless’ gifts of Della and Jim showed their …………
(a) innocence
(b) stupidity
(c) ignorance
(d) deep love for each other.
Answer:
(d) deep love for each other.

A Gift for Christmas Summary & Translation in English

A Gift for Christmas Introduction:
Jim and Della were husband and wife. They had great love for each other. There were two precious possessions in their house. One was Jim’s gold watch. The other was Della’s hair. It was Christmas eve. They wished to give something wonderful as a gift to each other. But they had no money to buy the gifts. Della sold her hair and bought a platinum chain for Jim’s gold watch. On the other hand, Jim sold his gold watch and bought a beautiful set of combs for Della’s hair. But when they came back home, they found that their gifts were of no use to them. Jim was without his watch and Della was without her hair. But their love for each other made the Christmas eve most enjoyable for them.

A Gift for Christmas Summary & Translation in English

(Page 46)

One dollar and eighty-seven cents. That was all. And sixty cents of it was in pennies. Pennies saved one and two at a time. Three times Della counted it. And the next day would be Christmas. There was clearly nothing that Della could do except to throw herself on the dirty little couch and cry. While Della is crying let us take a look at her home which is a furnished flat at $8 a week. You see signs of poverty

wherever you turn your eyes. What else can you expect1 when Della’s husband, Mr. James Dillingham Young, earns just2 $20 a week ? Della finished crying. She went up to the looking-glass and began to powder her cheeks. Then she stood by the window and looked out dully at a grey cat walking on a grey fence in a grey backyard. Tomorrow would be Christmas Day, and she had only $1.87 with which to buy Jim a present. She had been saving every penny she could for months, with this result. Twenty dollars a week doesn’t go far. Expenses had been greater than she had calculated. They always are. Only $1.87 to buy a present for Jim. Her Jim. Oh, the many happy hours she had spent planning for something nice for him . Something fine and rare, worthy of the honour of being owned by Jim.

Suddenly Della turned away from the window and stood before the glass. Her eyes were shining brilliantly, but her face had lost its colour all of a sudden, Rapidly she pulled down her hair and let it fall to its full length.Now, there were two possessions of the James Dillingham Youngs in which they both took great pride. One was Jim’s gold watch that had been his father’s and his grandfather’s. The other was Della’s hair. Della let fall her beautiful hair and it looked like a cascade of brown waters.

It reached below her knees. Quickly and nervously she combed it and did it up again. For a minute she faltered. Tears appeared in her eyes.

(Page 47)

That was only for a moment. She put on her old brown jacket, she put on her old brown hat. With her eyes shining brightly she fluttered out of the door and down the stairs to the street. She stopped at a shop with the sign ‘Mme Sofronio. Hair Goods of All Kinds’. The shop was located on the second floor. Della ran up the stairs.
‘Will you buy my hair ?’ asked Della.
‘I buy hair,’ said Madame. ‘Take your hat off and let me have a look at it.’
Down came the brown cascade.

‘Twenty dollars,’ said Madame, lifting the beautiful hair with her experienced hand.
‘Give it to me quickly,’ said Della.
Della spent the next two hours in the stores eagerly looking for Jim’s present. She found it at last. It surely had been made for Jim and no one else. There was no other like it in any of the stores. It was a platinum watch-chain, simple but well made. It was worthy of the watch. As soon as she saw it she decided that it was the right present for Jim. She paid twenty-one dollars for it and hurried home with the 87 cents that remained.

When Della reached home, pleased with the present, she grew nervous as she thought calmly about what she had done. She looked at the reflection in the mirror long, carefully, and critically. She brought out her curling irons and began to curl her hair carefully. The tiny curls made her look like a schoolboy. ‘If Jim doesn’t kill me,’ she said to herself, ‘before he takes a second look at me, he’ll say I look like a boy. But what could I do ? Oh ! What could I do with a dollar and eighty-seven cents ?’

Page -48

At seven o’clock the coffee was made and everything arranged to get dinner ready. Jim was never late. Della sat on the corner of the table near the door with the watch chain in hater hand. Then she heard his step on the stairs. She turned white for just a moment. She prayed, ‘Please God, make him think I am still pretty.’

The door opened and Jim stepped in and closed it. He looked thin and very serious. Poor fellow, he was only twenty- two and he was burdened with a family . He needed a new overcoat and he was without gloves. Jim’s eyes were fixed on Della, and there was an expression in them that she could not read, and it terrified her. It was not anger, nor surprise. He simply stared at her with a strange expression on his face.

Della got off the table and moved towards him. ‘Jim, darling,’ she cried,‘don’t look at me that way. I had my hair cut off and sold it because I had to buy a Christmas present for you. I just had to do it. My hair grows so fast you don’t mind, do you ? Say Merry Christmas ! Jim, and let’s be happy. You don’t know what a nice what a beautiful present I’ve got for you.’

You’ve cut off your hair ?’ asked Jim, speaking with difficulty.‘Cut it off and sold it,’ said Della. ‘Don’t you like me just as well , without my hair ?’ Jim looked about the room curiously . You say, your hair is gone ?’ he said with an air almost of disbelief .You needn’t look for it,’ said Della. ‘It’s sold, I tell you sold and gone. It’s Christmas Eve, Jim. Be good to me, because I did it all for you.’

Jim seemed to wake up at last, and to understand. He kissed Della. He suddenly remembered that he had brought something for Della too. He drew a package from his overcoat pocket and threw it upon the table.

Page – 49

‘Don’t make any mistake, Della,’ he said, ‘about me. Whatever happens I shall always love you just the same. Now open the package and you will understand why I behaved as I did.’ Della’s white fingers quickly opened the package. And then at first a scream of joy followed by a quick feminine change to tears.

For there lay The Combs the set of combs, side and back, that Della had seen in a Broadway window and liked so much. They were beautiful combs, so expensive and they were hers now. But alas, the hair in which she was to wear them was sold and gone ! She took them up lovingly, smiled through her tears and said, ‘My hair grows so fast, Jim !’
And then Della jumped up like a little cat and cried, ‘Oh, oh !’

Jim had not yet seen his beautiful present. She held it out to him eagerly on her open palm.
‘Isn’t it lovely, Jim ? I hunted all over town to find it. You’ll have to look at your watch a hundred times a day now. Give me your watch. I want to see how it looks on it.’

Instead of obeying, Jim sat down on the couch and put his hands under the back of his head and smiled.
‘Dell,’ said he, ‘let’s put our Christmas presents away and keep them awhile. They are too nice to use just at present. I sold the watch to get the money to buy your combs. And now please get the dinner ready.’

A Gift for Christmas Summary & Translation in Hindi

A Gift for Christmas Introduction:
जिम और डैला पति-पत्नी थे। उनके दिलों में एक-दूसरे के लिए बहुत प्यार था। उनके घर में दो बहुमूल्य वस्तुएं थीं। एक तो जिम की सोने की घड़ी थी। दूसरी डैला के बाल थे। क्रिसमस की पूर्व-संध्या थी। वे एकदूसरे को कोई आश्चर्यजनक उपहार भेंट करना चाहते थे। परन्तु उनके पास उपहार खरीदने के लिए पैसे नहीं थे। डैला ने अपने बाल बेच दिए और जिम की सोने की घड़ी के लिए एक प्लैटिनम की जंजीर खरीद ली। दूसरी ओर, जिम ने अपनी सोने की घड़ी बेच दी और डैला के लम्बे बालों के लिए कंघियों का एक सुन्दर सैट खरीद लिया। परन्तु जब वे घर वापस आए तो उन्होंने पाया कि उनके उपहारों का उनके लिए कोई लाभ नहीं था। जिम के पास घड़ी नहीं थी और डैला के बाल नहीं थे। परन्तु उनके पारस्परिक प्यार के कारण क्रिसमस की संध्या उनके लिए अत्यन्त खुशी भरी हो गई।

A Gift for Christmas Summary & Translation in Hindi

(Page 46)

एक डॉलर और सत्तासी सैंट। केवल इतनी ही रकम थी। और इसमें भी साठ सैंट पेनियों (छोटे सिक्के) थे। वे पेनियां जो एक-एक और दो-दो करके जमा की गई थीं। डैला ने इसे तीन बार गिना। और अगले दिन क्रिसमस होनी थी। स्पष्ट रूप से डैला के पास कुछ अन्य करने को नहीं था, सिवाए इसके कि वह स्वयं को अपने छोटे-से गंदे सोफे पर पटक दे और रोने लगे। जिस दौरान डैला रो रही है, आइए हम उसके घर पर एक नज़र डाल लें जो कि आवश्यक वस्तुओं से सज्जित एक फ़्लैट है जिसका किराया आठ डॉलर प्रति सप्ताह है।

जिधर भी आप नज़र घुमाएं, आपको ग़रीबी के चिन्ह नज़र आएंगे। आप और क्या आशा कर सकते हैं जब डैला का पति, मिस्टर जेम्ज़ डिलिंगम यंग, प्रति $20 सप्ताह मात्र बीस डॉलर कमाता है ? डैला ने रोना बंद कर दिया। वह दर्पण के सामने गई और अपने गालों पर पाउडर लगाने लगी। फिर वह खिड़की की बगल में खड़ी हो गई और नीरस भाव से बाहर को देखा जहां एक धूसर रंग की बिल्ली धूसर रंग के पिछवाड़े में धूसर रंग के अहाते पर चली जा रही थी। अगला दिन क्रिस्मस का होने वाला था और उसके पास जिम के लिए उपहार खरीदने को मात्र 1.87 डॉलर थे। वह कई महीनों से प्रत्येक पैनी बचाती आ रही थी जो वह बचा सकती थी और उसका परिणाम केवल इतना हुआ था।

प्रति सप्ताह बीस डॉलर ज़्यादा नहीं चलते हैं। खर्चे उससे ज़्यादा हो जाते जितना वह अनुमान लगाया करती। वे हमेशा हो जाते हैं। जिम के लिए उपहार $1.87 खरीदने को मात्र 1.87 डॉलर। उसका अपना जिम। ओह, कितने प्रसन्नतापूर्ण घण्टे उसने जिम के लिए किसी बढ़िया चीज़ की योजना बनाते हुए बिताए थे! कोई ऐसी चीज़ जो बढ़िया और दुर्लभ हो, जो जिम द्वारा रखे जाने के सम्मान की पात्र हो।

अचानक डैला खिड़की से हटी और दर्पण के सामने खड़ी हो गई। उसकी आंखें तेज़ चमक लिए हुए थीं किन्तु उसका चेहरा अचानक ही अपनी सारी लालिमा खो बैठा। शीघ्रता से उसने अपने बाल खोल कर नीचे किए और उन्हें उनकी पूरी लंबाई तक गिरने दिया। अब जेम्ज़ डिलिंगम यंग परिवार के पास दो कीमती चीजें थीं जिन पर वह दोनों बहुत गर्व करते थे। एक तो जिम की सुनहरी घड़ी थी जो उससे पहले उसके पिता और उसके दादा के पास रह चुकी थी। दूसरी चीज़ डैला के बाल थे। डैला ने अपने सुंदर बालों को नीचे तक गिरने दिया और ये भूरे पानी के एक झरने के जैसे लग रहे थे। ये उसके घुटनों के नीचे तक पहुंच रहे थे। जल्दी से और घबराहटपूर्वक उसने बालों में कंघी की और उन्हें फिर से बान्ध लिया। एक पल के लिए वह हिचकिचा गई। उसकी आंखों में आंसू भर आए।

(Page 47)

ऐसा केवल एक पल ही रहा। उसने अपनी पुरानी भूरी जैकेट पहनी तथा अपना पुराना भूरे रंग का हैट पहन लिया। अपनी आंखों में एक तेज़ चमक लिए हुए वह तेज़ी से दरवाजे से बाहर निकली और सीढ़ियों से उतर कर गली में आ गई। वह एक दुकान के पास रुकी जहां लिखा था’ ‘मैडम सोफ्रोनियो। बालों से बनी सभी प्रकार की चीजें’। दुकान दूसरी मन्ज़िल पर स्थित थी। डैला भागती हुई सीढ़ियों से ऊपर को गई। “क्या आप मेरे बाल खरीदेंगी ?” डैला ने पूछा। “हां, मैं बाल ही खरीदती हूं,” मैडम ने कहा। “अपना हैट उतारो और मुझे इन्हें एक नज़र देखने दो।” भूरा झरना तुरन्त नीचे को बह आया।

“बीस डॉलर,” मैडम ने उन संदर बालों को अपने अभ्यस्त हाथों से उठाते हुए कहा। “जल्दी से यह मुझे दे दीजिए,” डैला ने कहा। डैला ने अगले दो घंटे जिम के लिए उपहार की उत्सुकतापूर्वक खोज करते हुए दुकानों में बिताए। अंत में उसे यह मिल गया। निश्चय ही यह जिम के लिए बनाया गया था, किसी भी अन्य के लिए नहीं। इसके जैसा कोई अन्य किसी भी दुकान में नहीं था। यह प्लैटिनम की बड़ी एक घड़ी वाली चेन थी, सादी किन्तु अच्छी बनी हुई। यह उस घड़ी के लिए उपयुक्त थी। ज्योंही डैला ने इसे देखा, उसने निश्चय कर लिया कि जिम के लिए यह बिल्कुल उपयुक्त उपहार था। उसने चेन के लिए इक्कीस डॉलर का भुगतान किया और बचे हुए सत्तासी सैंट लिए हुए तेज़ी से घर की तरफ चल दी।

जब डैला अपने उपहार पर प्रसन्न होती हुई घर पहुंची तो वह घबराने लगी जब उसने शांतिपूर्वक विचार किया कि वह क्या कर बैठी थी। दर्पण में अपने प्रतिबिम्ब को वह बड़े ध्यान से, आलोचनात्मक ढंगपूर्वक लंबे समय तक देखती रही। उसने बाल धुंघराले करने वाली अपनी लोहे की कंघियां निकाली और सावधानीपूर्वक अपने बालों को धुंघराले बनाने लगी। उन छोटे-छोटे छल्लों में वह एक स्कूली लड़के जैसी लग रही थी। “कहीं जिम मुझे मार ही न दे,” उसने स्वयं से कहा, “इससे पहले कि वह मुझ पर दूसरी नज़र डाले, वह कहेगा मैं एक लड़के जैसी लगती हूं। किन्तु मैं क्या कर सकती थी? ओह ! मैं एक डॉलर और सत्तासी सैंट से क्या कर सकती थी ?”

(Page 48)

सात बजे उसने काफ़ी बनाई और रात्रि भोज तैयार करने के लिए सभी चीजें तैयार कर लीं। जिम कभी देर से नहीं आता था। घड़ी की चेन अपने हाथ में लिए हुए डैला दरवाजे के पास एक मेज के कोने पर बैठ गई। तब उसे सीढ़ियों से आती जिम के कदमों की आवाज़ सुनाई दी। वह केवल एक पल के लिए सफ़ेद पड़ गई। वह प्रार्थना करने लगी, “हे ईश्वर, कृपा करके उसे यह विचार देना कि मैं अभी भी सुंदर हूँ।” दरवाजा खुला और जिम ने अंदर कदम रखा और इसे बंद कर दिया। वह दुबला और बहुत गंभीर लग रहा था। बेचारा जिम, वह सिर्फ बाईस वर्ष का था और परिवार के बोझ में दबा था! उसे एक नए ओवर कोट की ज़रूरत थी और उसके पास दस्तानें नहीं थे। जिम की नज़र डैला पर टिकी थी और उसकी आँखों में एक ऐसा भाव था जिसे डैला पढ़ न पाई और इससे वह भयभीत हो उठी। उस भाव में न क्रोध था और न ही आश्चर्य । वह अपने चेहरे पर एक विचित्र-सा भाव लिए उसकी तरफ़ टकटकी लगाए देखता रहा। डैला मेज़ से नीचे उतरी और जिम की तरफ बढ़ी। “जिम, मेरे प्रिय,” उसने चिल्लाते हुए कहा, “मुझे इस

तरह न देखो। मैंने अपने बाल कटवा दिए और बेच दिए क्योंकि मुझे तुम्हारे लिए क्रिसमस का उपहार खरीदना था। मुझे ऐसा करना ही था। मेरे बाल बहुत जल्दी बढ़ आते हैं, तुम्हें बुरा तो नहीं लगा है, क्या लगा है ? जिम, ‘शुभ क्रिसमस!’ कहो और आओ हम खुशी मनाएँ। तुम नहीं जानते मैं तुम्हारे लिए कितना बढ़िया,कितना सुंदर उपहार लाई हूं।” “तुमने अपने बाल कटवा दिए ?” जिम ने पूछा,
मुश्किल से बोलते हुए। “हाँ, कटवा दिए और बेच दिए.” डैला ने कहा। “क्या तुम मुझे बालों के बिना भी उतना ही पसंद नहीं ? करते हो ?” जिम ने उत्सुकतापूर्वक कमरे में इधर-उधर देखा।
“तुम कहती हो तुम्हारे बाल नहीं रहे ?” उसने लगभग अविश्वास के भाव से कहा।

“तुम्हें उन्हें ढूँढने की कोई जरूरत नहीं है,” डैला ने कहा। “वे बिक चुके हैं, मैं तुम्हें बता रही हूं बिक चुके हैं और जा चुके हैं। आज क्रिसमस की पूर्व-संध्या है, जिम। मेरे प्रति अच्छे बने रहो क्योंकि मैंने वह सब तुम्हारी खातिर किया था।” अन्त में मानो जिम जाग उठा हो और समझने लगा हो। उसने डैला को. चूमा। अचानक उसे याद आया कि वह डैला के लिए भी एक उपहार लाया था। उसने अपने ओवरकोट की जेब में से एक पैकट बाहर निकाला और इसे मेज़ पर फेंक दिया।

Page – 49

“डैला, मेरे विषय में कोई ग़लत मत सोचो,” उसने कहा, “यद्यपि कुछ भी हो जाए, मैं हमेशा तुम्हें उतना ही प्यार करता रहूंगा। अब पैकेट को खोलो और तुम समझ जाओगी कि मैंने वैसा व्यवहार क्यों किया जो मैं कर रहा था।” डैला की सफ़ेद अंगुलियों ने तेज़ी से पैकेट को खोला। और फिर पहले तो प्रसन्नता-भरी एक चीख़ निकली और इसके बाद औरतों वाले आंसू बहने शुरू हो गए। क्योंकि वहां वे कंघियां पड़ी हुई थीं – कंघियों का एक सैट जिसे डैला ने ब्रॉडवे बाज़ार की एक दुकान पर खिड़की में देखा था और उन्हें बहुत पसंद किया था।

वे सुंदर कंघियां थीं, बहुत कीमती तथा अब वे उसकी थीं। किन्तु अफसोस कि वे बाल जिनमें उसने ये पहननी थीं, बिक चुके थे और जा चुके थे! डैला ने प्यार से उन कंघियों भीतर से मुस्कराई और बोली, “मेरे बाल बहुत जल्दी बढ़ आते हैं, जिम !” और तब डैला एक छोटी बिल्ली की भांति उछली और चिल्लाई, “वाह, वाह !” जिम ने अभी अपना सुंदर उपहार नहीं देखा था। डैला ने इसे उत्सुकतापूर्वक अपनी खुली हथेली पर रखकर उसकी तरफ़ बढ़ाया। “क्या यह सुंदर नहीं है, जिम ? मैंने इसे पाने के लिए पूरा शहर छान मारा। अब तुम्हें दिन में सौ बार अपनी घड़ी की तरफ़ देखना पड़ेगा। लाओ, मुझे अपनी घड़ी दो। मैं देखना चाहती हूं कि यह इस पर कैसी लगती है।”

उसका कहा मानने की बजाए, जिम सोफे पर बैठ गया, और उसने अपने हाथ अपने सिर के पीछे रख लिए और मुस्कराया। “डैल,” उसने कहा, “आओ, हम अपने-अपने क्रिसमस उपहार एक तरफ़ रख दें और थोड़ी देर के लिए इन्हें पड़ा रहने दें। वे इतने अच्छे हैं कि उनका प्रयोग वर्तमान में अभी नहीं किया जा सकता। तुम्हारी कंघियां खरीदने के लिए पैसे प्राप्त करने को मैंने घड़ी बेच दी। और अब कृपया खाना तैयार कर दो।”

 

Punjab State Board PSEB 10th Class Science Important Questions Chapter 6 Life Processes Important Questions and Answers.

PSEB 10th Class Science Important Questions Chapter 6 Life Processes

Long Answer Type Questions

Question 1.
What are the kinds of heterotrophic organisms on the basis of nutrition?
Answer:
Heterotrophic nutrition is a mode of nutrition in which organisms obtain readymade organic food from outside source. The organisms that depend upon outside sources for obtaining organic nutrients are called heterotrophs. It is a characteristic feature of all animals and non-green plants, that are unable to utilize carbon and synthesi s organic compounds necessary for life, but depends upon organic sources of carbon. They are thus dependent upon autotrophic organisms (Plants) and are called as heterotrophs.

It is of the following types :

• Saprophytic nutrition: In this type of nutrition, an organism lives upon dead organic sources such as dead plants and dead animals. These usually secrete dissolving and digesting enzymes and absorb the liquefied molecules so formed e.g. yeast, bread moulds and dung moulds etc.
• Parasitic nutrition: In this type of nutrition, an organism lives totally at the expense of others and derives its food material and shelter from the other .These organisms which derive food material are called parasites and the organism from which food is derived is called as host. This type of nutrition is termed as parasitic or holozoic nutrition: It is also known as parasite-host relationship e.g. Cuscuta, Ascaris etc.
• Holozoic nutrition. It is a mode of heterotrophic nutrition which involves intake of solid pieces of food. Since solid food is taken in, Holozoic nutrition is also called ingestive nutrition. Holozoic nutrition (GK. “Holo”-Whole; “Zoon”-Animal) is found in animals and protists. The food may consist of another animal, plant or its parts.

Depending upon the source of food, holozoic organisms are of three types :

1. Herbivores: These organisms obtain their food from plants e.g. cow, rat, deer and goat etc.
2. Carnivores: These organisms take the flesh of other organisms as their food e.g. tiger, cheetah, snake, eagle etc.
3. Omnivores: These can feed on plants and flesh of other organisms e.g. human, cockroach, crow etc.

Question 2.
What is photosynthesis? Describe the significance of photo-synthesis.
Answer:
Photosynthesis (Photos-Light, Synthesis-putting together) may be defined as an anabolic process in which green plants manufacture complex organic food substances (carbohydrate) from simple inorganic compounds like carbon dioxide and wrater in presence of sunlight with the aid of chlorophyll and evolve out oxygen as a byproduct of the process. Thus photosynthesis is a process in which radiant energy is converted into chemical energy

In other words photosynthesis is a series of oxidation- reduction reaction in which CO₂ is reduced and H₂O is oxidized to produce carbohydrates and oxygen.

• Chloroplasts are the actual sites for photosynthesis.
• All green parts of a plant are involved in photosynthesis.
• Leaves are the most important organs of photosynthesis.

Section of Leaf showing site of photosynthesis

Significance of photosynthesis:

• Photosynthesis is a source of all our food and fuel. It is the only biological process that acts as the driving vital force for the whole animal kingdom and for the non-photosynthetic organisms.
• It drives all other processes of biological and abio- logical world. It is responsible for the growth and sustenance of our biosphere.
• It provides organic substances, which are used in the production of fats, proteins, nucleoproteins, pigments, enzymes, vitamins, cellulose, organic acids, etc. Some of them become structural parts of the organisms.
• It makes use of simple raw materials such as CO₂, H₂O and inexhaustible light energy for the synthesis of energetic organic compounds.
• It is significant because it provides energy in terms of fossil fuels like coal and petrol obtained from plants, which lived millions and millions of years ago.
• Plants, from great trees to microscopic algae, are engaged in converting light energy into chemical energy, while man with all his knowledge in chemistry and physics cannot imitate them.

Question 3.
Which organelle is responsible for photosynthesis? Describe the role of chlorophyll.
Answer:
Chloroplast is the organelle responsible for photosynthesis. Chloroplasts contain green pigment called as chlorophyll. Photosynthetic pigments occur in the granum. They constitute the pigment system called photosystem. About 250 to 400 pigment molecules are present in a photosystem.

The primary function of photosystems is to trap light energy and converts it to chemical energy.

• Chloroplast was discovered by Schimper.
• Number of chloroplasts is variable in different species of plants.
• In lower plants like algae they are 1 or 2 number.
• In higher plants their number varies from 40 -100 per palisade cell or more.
• Chloroplasts also have variable shapes, for example cup-shaped, ribbon-shaped etc. in algae while it is discoidal in higher plants.

A typical structure of chloroplast is a double membranous structure having two parts.

• Grana: It is a lamellar system consisting of stacks of granum lamella each bounded by a membranous box called as thylakoid. They are 40 – 60 per cell. Number of thylakoids per grana is 50 or more. Chlorophyll molecules are found inside the thylakoid membrane where they trap solar energy in the form of small energy packets called ‘photon’ or ‘quanta’. Grana are interconnected to each other by a channel called as stroma lamellae or Fret’s channel.
• Stroma: It is a non-pigmented proteinaceous matrix in which grana remain embedded. It contains enzymes for dark reaction.
• Mechanism of Photosynthesis: Photosynthesis is formation of organic food from carbon dioxide and water with the help of sunlight inside chlorophyll containing cells. Oxygen is produced as by-products.

Oxygen comes from water. Hydrogen of water is used to reduce carbon dioxide to form carbohydrate.

Photosynthesis occurs in two main steps:

• The first step is dependent upon light and the second step is not dependent upon light. Hence, the former is called light reaction or photochemical phase while the latter, the dark reaction or biosynthetic phase of photosynthesis.
• Water is split up during photosynthesis by the process called photolysis. It provides reductant for carbon dioxide. Oxygen is liberated. All the liberated oxygen, therefore, comes from water.
• The photolysis of water in photosynthesis was discovered by Hill and hence it is also known as Hill reaction.
• The light reaction of photosynthesis is followed by the dark reaction. In this, CO₂ is first fixed by ribulose diphosphate and from this fixed CO₂ phosphoglyceric acid is formed. The phosphoglyceric acid thus formed ultimately forms carbohydrates.
• The basic organic compound formed in photosynthesis is often considered to be glucose. The storage product of plants is commonly starch.
• A chemical equation of photosynthesis is

In plants and most algae it occurs in the chloroplasts i.e., light reaction and dark reaction.

Question 4.
Discuss the steps of light reaction and dark reaction.
Answer:
Steps of light reaction.
Two main steps of light reaction are :
(a) Photolysis of water
(b) Conversion of fight energy into chemical energy.

• Light reaction takes places in the thylakoid membranes and the intergranal lamellae of the chloroplast in the presence of fight.
• Two photosystems (PSI and PSII) work in a coordinated manner.
• H₂O splits into H⁺ and OH^–.
• H+ is used to reduce NADP to NADPH₂ which is used in dark reaction.
• Photophosphorylation takes place in two ways—cyclic and non-cyclic.
• Light energy is converted into chemical energy.
• The end-products are ATP and NADPH₂.
• As a result of photolysis of water, oxygen is evolved as a by-product.
  4H₂O → 4 OH^– + 4 H⁺
  4 OH^– + 4e^– → 4 OH^–
  OH → 2H₂O + O₂

Summary of dark reaction :

• Dark reaction takes place in the stroma of the living chloroplast.
• Atmospheric CO₂ is absorbed.
• The end products of fight reaction (ATP and NADPH₂) are also used.
• All green plants operate C₃ photosynthetic pathway. Some monocot plants like maize, sugarcane operate both C₃ and C₄ photosynthetic pathways.
• First end product of photosynthesis is sugar.

Question 5.
Explain process of nutrition in Amoeba.
Answer:
Nutrition in Amoeba. Amoeba is omnivorous, i.e. it feeds on smaller animals, plants, micro-organisms and fragments of larger organisms. Nutrition is holozoic. Ingestion can occur at any place on the surface since a regular mouth is absent. Ingestion occurs through phagocytosis or engulfing the food particle in an invagination of the body. The engulfed food particle comes to fie inside a food vacuole. The latter is surrounded by a membrane.

Digestion of food within food vacuole

Digestion: The digestion is intracellular and the food vacuoles act as temporary stomach for digestion.
Absorption: It occurs by diffusion and distribution takes place by cyclosis.
Assimilation: Assimilation of digested material occurs in a single cell.
Egestion: The undigested food is eliminated through the surface of the cell, where the food vacuole containing the undigested food bursts and discharges its contents to the outside.

Question 6.
Difference between the followings :
(i) Autotrophic and Heterotrophic nutrition
(ii) Herbivore and Carnivore.
Answer:
(i) Autotrophic and Heterotrophic nutrition :

Autotrophic Nutrition	Heterotrophic Nutrition
1. Food is self-manufactured.	1. Food is obtained readymade from outside.
2. An external source of energy is required for synthesis of food.	2. An external source of energy is not required. The required energy is present in the food obtained from outside.
3. Inorganic substances constitute the raw materials for manufacturing food.	3. Inorganic substances are not much required.
4. Chlorophyll is present for trapping light energy.	4. Chlorophyll is absent
5. Digestion is absent.	5. An external or internal digestion is required for conversion of complex organic materials into simpler and soluble ones.
6. Organisms performing autotrophic nutrition function as producers. Examples: Green plants, some bacteria, some protists.	6. Organisms performing heterotrophic nutrition function as consumers. Animals, many protists and monerans.

(ii) Herbivore and Carnivore

Herbivore	Carnivore
Animals winch cat only plants. e.g. Cow, goat etc.	They feed on flesh of other animals, e.g. Lion, vulture etc.

Question 7.
Describe human alimentary canal. Draw a labelled diagram of human alimentary canal.
Or
Describe the human alimentary canal with the help of a suitable diagram.
Answer:

• Mammalian (human) alimentary canal comprises mouth, buccal cavity, pharynx, oesophagus, stomach, small intestine (duodenum, jejunum and ileum), large intestine (caecum, colon and rectum) and anus.
• The mouth, bounded by two lips open into oral cavity.
• Buccal cavity contains teeth and tongue, and receives saliva from 3 pairs of salivary glands. Teeth are meant for cutting and mastication of food.
• Pharynx: It is a vertical tube. It is a cross passage for food and air. It has uvula and epiglottis which closes the internal nares and glottis respectively during swallowing of food to ensure the passage of food into oesophagus (food pipe).
• Oesophagus: It is a 25 cm long narrow muscular straight tube. It opens into stomach. Oesophagus propels the swallowed food into stomach.
• Stomach: It is a sac-like structure situated in the upper part of abdominal cavity below the diaphragm. Large part of this sac is situated left of the median line.
• Small Intestine: It is the longest part of alimentary canal. It is thin-walled and highly coiled tubular structure. It is about 3-3.5 metres long and occupies most part of abdominal cavity. It is coiled upon itself. Its inner lining is thrown into numerous villi.

Human digestive system.

Large intestine: The large intestine is about 1.5 metres long. It is divided into following parts, i.e. the vermiform appendix, the colon and the rectum. Caecum is a blind tube and represented by vermiform appendix (5-8 cm) and is present below the junction of small and large intestine. Rectum is the last part and opens to the outside by anus guarded by anal sphincter.

Question 8.
Describe the process of digestion of food in man.
Answer:
Digestion: The process of conversion of non-diffusible form of food into the simple and diffusible form by chemical and mechanical processes in the alimentary canal is called digestion.

• The process of digestion starts in the mouth cavity and is completed in the intestine.
• In the mouth, food gets mixed up with saliva secreted by salivary glands.
• Saliva contains an enzyme ptyalin (salivary amylase) which breaks polysaccharide starch into disaccharide maltose.

• The food from the mouth cavity called bolus passes into the stomach through the oesophagus.
• The gastric glands of the stomach secrete gastric juice which contains hydrochloric acid, protein digesting
• enzyme-pepsin Rennin, mucus and small amount of gastric lipase are also components of gastric juice.
• Pepsin breaks down proteins into peptones and proteoses in acidic medium of stomach.
• Rennin undies the milk.
• Muscles present on the wall of stomach churn and propel the food called chyme forward into duodenum.
• The digested food moves from stomach to duodenum of the small intestine.
• Duodenum receives bile from juices from liver and pancreatic juice from pancreas.
• The pancreatic juice contains trypsin, amylase and lipase.
• The proteins, fats and carbohydrates are further digested into diffusible form amino acids, glycerol and fatty acids, glucose and fructose.
• The intetinal juice consists of amylolytic, proteolytic and lipolytic enzymes.
• Finally, the digestion is completed in the ileum with the secretion of the intestinal juice by intestinal glands.
• Emulsion form of food called chyle is ready for absorption.

Question 9.
Name the constituents of blood and state the functions of each.
Answer:

Constituents	Functions
1. Plasma, (i) Serum	It contains proteins as well as organic and inorganic substances in solution.
(ii) Fibrinogen	It serves to carry the nutritive and waste materials, antibodies, enzymes and hormones.
2. Red blood corpuscles (R.B.Cs.)	Clotting of blood.
(Erythrocytes)	They help to transport oxygen.
3. White blood corpuscles (W.B.Cs)	They help to defend our body against bacteria, as well as the toxins which these organisms may produce. They also help to remove useless dead tissues from the blood.
4. Blood Platelets or Thrombocytes	They play a vey important role in bringing about the coagulation of blood.

Question 10.
State the functions of blood.
Answer:
Blood performs a number of functions in the body, the most important of which are as follows :

• Blood supplies nutrients and oxygen to various organs and cells of the body.
• It carries the waste matter formed in the cells to the excretory organs.
• It regulates the temperature of the body.
• It supplies hormones to different parts of the body.
• It prevents the body from various diseases by destroying the pathogenic germs.
• It prevents excessive loss of nutrients from cuts and wound by forming a clot.

Question 11.
Describe the structure of human heart.
Answer:
Heart.

• It is a highly efficient, pumping organ of body. Human heart consists of 4 chambers: upper smaller right and left atria (auricles) with thinner wall and lower larger right and left ventricles with thicker walls.
• Atria open into the respective ventricles by atrioventricular apertures guarded by atrioventricular valves.
• The two atria are separated from each other by interatrial septum, and the two ventricles are separated from each other by interventricular septum.
• The sinoatrial node (SAN) or the pacemaker is located in the upper wall of right atrium.

Valves of the heart.
Valves are muscular flaps which prevent the blood to flow back through it. Two types of heart valves are distinguished :

1. The Atrioventicular valves: These valves separate the atria from the ventricles. The right side of the heart possesses the tricuspid valve or right atrioventricular valve and the left side of the heart possesses the bicuspid or mitral valve.
2. Semilunar valves: These are located in the arteries leaving the heart. The pocket-shaped pulmonary semilunar valves lies in the opening where the pulmonary trunk leaves the right ventricle and aortic semilunar valve lies at the opening between the left ventricle and aorta.

Question 12.
Draw Human heart and label its parts.
Or
Draw a sectional view of the human heart and label on it, Aorta, Right Ventricle and Pulmonary veins.
Answer:
Human Heart

V.S. of Human heart.

Question 13.
Explain respiratory system of human.
Answer:

Human respiratory system

Question 14.
Describe the mechanism of breathing in human beings.
Answer:
Mechanism of breathing
Breathing. It is simply inhaling fresh air rich in oxygen and exhaling foul air rich in carbon dioxide. Respiratory system of man consists of :

1. Respiratory tract.
2. Respiratory organs (lungs).

Respiratory tract. It is the tract or the path through which fresh air enters the body reaches the lungs and foul air (rich in CO₂) leaves the lungs to come out. It consists of Nasal cavity → Pharynx → Larynx → Trachea → Bronchi → Bronchioles → Alveoli (of Lungs).
Breathing is accomplished through changes in size and air pressure of chest cavity. It involves Inspiration and Expiration.

Inspiration:
Intake of fresh air is called inspiration. It occurs when the chest cavity is increased in size and therefore decrease in pressure.

Expiration:
The expulsion of foul air (rich in CO₂) from lungs is called expiration. It results when the chest cavity is reduced in size.

Question 15.
Draw a well labelled diagram of human excretory system.
Answer:
Human Excretory System.

Human excretory system.

Question 16.
Describe the structure of human urinary system.
Answer:
The urinary system consists of the following :

1. Kidneys
2. Ureters
3. Urinary bladder
4. Urethra.

1. Kidneys: The kidneys are a pair of bean-shaped delicate organs. They are situated one on each side of the mid-dorsal line of the abdominal cavity, just below the level of the stomach.

2. Ureters: They are two tubes about 30 cm long, emerging from each kidney with the pelvis of which they are continuous. The ureters run downwards and inwards and open into the urinary bladder.

3. Urinary bladder: It serves as a reservoir for the urine. It is a hollow muscular organ lined by stratified epithelium. Its average capacity for storage is about 500 mm. It is situated in the cavity of the pelvis just behind the pubic symphysis.

4. Urethra: The urethra in two sexes differ. The male urethra is about 20 cm in length. The female urethra is a short duct of about 4 cm long and it extends from the urinary bladder to the external urethra orifice which is in the vestibule just above and anterior to the vaginal orifice.

Short Answer Type Questions

Question 1.
What are life processes?
Answer:
Life processes: Every living organisms takes food, derives energy, removes wagte materials from their bodies and responds to changes in their environment. These activities are called life processes. In all living organisms there occur the basic life processes such as nutrition, respiration, transportation, excretion and reproduction, which are necessary for survival.

Question 2.
What is nutrition? Briefly explain the two major kinds of nutrition.
Or
Define autotrophic nutrition.
Answer:
Nutrition: All living organisms need matter to build up the body and energy to operate the metabolic reaction that sustains life. The materials which provide these two primary requirements of life are called nutrients or foods. The sum total of processes by which organisms obtain matter and energy is termed nutrition.

Modes of Nutrition:
1. Autotrophic or Holophytic nutrition: All green plants and certain protozoans (Euglena) have evolved a mechanism to directly use the energy7 of sunlight for preparing organic food in their own body from simple raw materials i.e. C02 and H20. These simple inorganic materials are transformed into glucose and oxygen is evolved.

2. Heterotrophic Nutrition: Animal, fungi, (Amoeba) and many bacteria cannot utilize solar energy. They use chemical bond-energy of organic molecules synthesized by other organisms in building their own organic molecules. Such a mode of feeding is termed as heterotrophic nutrition, and the organisms having it are called heterotrophs.

It is of three types :

1. Saprophytic
2. Parasitic
3. Holozoic.

Question 3.
Write a note on saprophytic nutrition.
Answer:
Saprophytic nutrition (Sapros = rotten; phyton = plant) It this organism releases some juices to soften or digest the food and then absorbs the nutrient. Thus they decompose the dead organic matter into simpler substance. Fungi (yeast, moulds, mushrooms) and many bacteria are saprophytic in nutrition.

The saprophytic mode of nutrition can best be exemplified by the common bread mould, Rhizopus. It converts the complex organic food materials of bread i.e. starch into soluble sugars with the help of starch digesting enzymes. These soluble sugars are then absorbed by the fungus.

Question 4.
Explain the two main steps of photosynthesis.
Answer:
Photosynthesis occurs in two main steps.

• The first step is dependent upon light and the second step is not dependent upon light. Hence, the former is called light reaction or photochemical phase while the latter, the dark reaction or biosynthetic phase of photosynthesis.
• Water is split up during photosynthesis by the process called photolysis. It provides reductant for carbon dioxide. Oxygen is liberated. All the liberated oxygen, therefore, comes from water.
• The photolysis of water in photosynthesis was discovered by Hill and hence it is also known as Hill reaction.
• The light reaction of photosynthesis is followed by the dark reaction. In this, CO₂ is first fixed by ribulose diphosphate and from this fixed CO₂ phosphoglyceric acid is formed. The phosphoglyceric acid thus formed ultimately forms carbohydrates.
• The basic organic compound formed in photosynthesis is often considered to be glucose. The storage product of plants is commonly starch.
• A chemical equation of photosynthesis is

In plants and most algae it occurs in the chloroplasts i.e., light reaction and dark reaction.

Question 5.
Give a brief account of factors affecting the process of photosynthesis.
Answer:
Factors affecting the process of photosynthesis.

• Temperature: The rate of photosynthesis increases with increase in temperature upto a maximum of 35°C. However, the rate starts decreasing if the temperature rises beyond 30°C.
• Water: The rate of photosynthesis is slow in water-deficient conditions.
• Carbon dioxide: The rate of photosynthesis increases with an increase in carbon dioxide concentration upto a certain level, beyond which there is no effect on the rate of photosynthesis.
• Anatomy of leaf
• Chlorophyll contents.

Question 6.
What are stomata? Explain role in respiration.
Or
How respiration takes place in roots and stems in plants?
Answer:
Respiration in plants. Plants, during the process of photosynthesis, give off oxygen which is utilized during respiration.

Plant respiration occurs at slower rate.

• In the leaves Stomata are the openings located on the surface of the leaves which are guarded by two kidney-shaped guard cells. Through stomatal opening, air can pass into or out of leaves.
• In woody stems. Lenticelo are the breathing pores located on the surface of the woody stems through which air can pass. Plants do not have any specialised ventilation mechanism.
• In roots. Roots take up oxygen present in between particles through root hairs by diffusion. Root hairs are simple extensions of epidermal cells of root in contact with soil.

In the older parts of roots: Older portions of root hairs lacks root hairs. They are covered with protective layer of dead cells having very small openings called lenticels through which gaseous exchange take place between soil and inner living cell.

Question 7.
Demonstrate with experiment that O₂ is evolved during photosynthesis.
Answer:
Take a beaker filled with water. Add a pinch of baking soda (NaHCO₃) to it and put a Hydrilla plant (Aquatic plant) in it. Cover the plant with a funnel. Invert a test tube containing water over the stem of the funnel. Keep this apparatus in the bright sunlight. After some time bubbles start emerging out from the plant, which gets collected in the upper part of the test tube. Remove the test tube and test the gas with a lighted splinter, it keeps on glowing showing that the gas is a supporter of combustion. Thus, the experiment clearly shows that O₂ is evolved during photosynthesis.

Question 8.
To demonstrate that photosynthesis take place in the presence of chlorophyll
Procedure :

• Take a potted plant with variegated leaves-for example, money plant or crotons.
• Keep the plant in a dark room for three days so that all the starch gets used up.
• Now keep the plant in the sunlight for about six hours.
• Pluck a leaf from the plant. Mark the green areas in it and trace them on a sheet of paper.
• Dip the leaf in boiling water for a few minutes.
• After this immerse it in a beaker containing alcohol.
• Carefully place the above beaker in a water-bath and heat till the alcohol begins to boil.
• What happens to the colour of the leaf? What is the colour of the solution?
• Now dip the leaf in a dilute solution of iodine for a few minutes.
• Take out the leaf and rinse off the iodine solution.
• Observe the colour of the leaf and compare this with the tracing of the leaf done in the beginning (Fig.).

What can you conclude about the presence of starch in various areas of the leaf?

• Observation and Conclusion: Only green patches of variegated leaf take on blue colour. Other parts remain unchanged.
• Photosynthesis take place only in chlorophyll-containing patches of leaf.

Question 9.
To demonstrate that CO₂ necessary for photosynthesis.
Answer:
Procedure:

• Take two healthy potted plants which are nearly of the same size.
• Keep them in a dark room for three days.
• Now place each plant on separate glass plates. Place a watch-glass containing potassium hydroxide by the side of one of the plants.

The potassium hydroxide is used to absorb carbon dioxide.

Experimetal set-up (a) with potassium hydroxide (b) without potassium hydroxide

• Cover both the plants with separate bell-jars as shown in Figure.
• Use vaseline to seal the bottom of the jars to the glass plates so that the set-up is air-tight.
• Keep the plants in sunlight for about two hours.
• Pluck a leaf from each plant and check for the presence of starch as in the above activity.
• Do both the leaves show the presence of the same amount of starch?

What can you conclude from this activity?
Observation and Conclusion. The plant containing CO₂ in the surrounding carry out photosynthesis. Other plant does not. It proves that CO₂ is essential for photosynthesis.

Question 10.
Demonstrate with experiment that light is essential for photosynthesis.
Answer:
Take a de-starched potted plant, which has been kept in dark for 3 to 4 days. Cover one of its leaves completely with a carbon paper so that no light falls on it. Keep the plant in light for 4 to 6 hours. Test the covered leaf and uncovered leaf for starch with iodine test. The covered leaf will show negligible amount of starch, while the uncovered leaf will give positive test for starch. The process clearly shows that light is necessary for photosynthesis.

Question 11.
How is respiration different from breathing?
Answer:
Differences between Breathing and Respiration

Breathing	Respiration
1. It is ventilation or bringing in of oxygenated air and giving out deoxygenated air.	1. Respiration of animals includes breathing, gaseous exchange and catabolic breakdown of food.
2. It is a physical process.	2. Respiration is both a physical and physiological process.
3. Breathing does not liberate energy.	3. It liberates energy.
4. It is restricted to organs where gaseous exchange occurs between blood and atmospheric air.	4. Respiration involves every living ceil of the body.

Question 12.
List three differences between respiration in plants and respiration in animals.
Answer:
Differences in respiration in plants and animals

Respiration in plants	Respiration in animals
1. All the cells of plant parts (root, stem, leaves) perform the respiration individually.	1. It is performed by specific respiratory organs for all the cells of body.
2. There is little transport of gases from one part to the other.	2. Transport of gases is maximum.
3. Rate of respiration is low.	3. Rate of respiration is high.

Question 13.
What is the function of epiglottis?
Answer:
Epiglottis is a flap like structure present at the top of glottis. It closes glottis during swallowing of food thus checks the entry of food into respiratory passage.

Question 14.
Why is food necessary for living organisms?
Answer:
Food provide energy to raw materials for growth and maintenance.

Utility of components of food.

• Carbohydrates are mainly used for producing energy.
• Fats serve as stored concentrated fuel for energy production.
• Proteins are mainly used to build up tissues.
• Mineral salts and vitamins regulate metabolic processes and growth.
• Water is essential for all biological activities.

Question 15.
Explain the mechanism of breathing in human.
Answer:
Inhalation or Inspiration

• The entry of air from outside into alveoli of lungs through respiratory tract is called inhalation.
• The air enters when thoracic cavity expands due to contraction of intercostal muscles attached to ribs and peripheral muscles of the diaphragm.
• Thus the thorax moves upward, outward and forward.
• It increases the volume of thoracic cavity and the pressure decreases.
• Thus air from outside rushes into alveoli of lungs through nostrils, nasal chambers, trachea, bronchi and bronchioles.
• The alveolar sac gets filled with oxygen rich air.

Exhalation or Expiration is concerned with the expelling of carbon dioxide from lungs.

• It takes place when the volume of the thoracic cavity decreases and the pressure of the contained air in the thoracic cavity increases.
• Air passes out through the respiratory tract from the lungs.

Question 16.
What is the effect of sternuos exercise on rate of breathing and why?
Answer:
Normally man breathes about 15-18 times per minute but during hard exercise the breathing rate increases to 20 to 25 times per minute. It is due to the fact that body needs more of energy thus requires more of oxygen.

Question 17.
Give an outline of Calvin-Benson Cycle.
Answer:
Melvin Calvin and Andy Benson discovered this cycle, hence it is called Calvin cycle.

Calvin-Benson Cycle

Question 18.
Label the parts in the figure.
Answer:

Answer:

1. Pseudopodium
2. Food particle
3. Ingestion
4. Food Vacuole
5. Waste
6. Digestion of food.

Question 19.
Describe the role of intestinal juice.
Answer:
Intestinal juice too is alkaline (pH 8.3).

It has many enzymes :

• Intestinal amylase hydrolyses the remaining starch and glycogen to maltose.
• Maltase changes maltose to glucose.
• Sucrase converts sucrose into glucose and fructose.
• Lactase hydrolyses lactose to glucose and fructose.
• Dipeptidases hydrolyse dipeptides to amino acids.
• Intestinal lipase splits emulsified fats into fatty acids and glycerol.
• Alkaline emulsion of digestion products formed in the small intestine is called chyle.

Question 20.
Explain absorption of food in the small intestine.
Answer:
Absorption. The process of diffusion of digested food into blood present in the blood capillaries of smail intestine is called absorption. Inner lining is thrown in fold called villi. They increase surface area for absorption of food.
Glucose, amino acid, vitamins, mineral salts and water diffuses into blood present in blood capillaries of numerous villi of the small intestine. The fatty acids and glycerol diffuses into lymph present in lymph vessels called lacteals. The digested food is carried to the liver by the hepatic portal vein. The fatty acid and glycerol unite in lymph to form fat. Most of the fat passes as a milky emulsion. After absorption, the undigested- food passes into large intestine.

Question 21.
State the functions of stomach and large intestine.
Functions of Stomach
Answer:

• Storage of food.
• Mechanical breakdown of food.
• Partial digestion of food.

Functions of large intestine
Colon:

• Its wall absorbs the water from undigested food.
• Absorption of digested food also takes place in this region which has not been absorbed by ileum.

Question 22.
Differentiate the following :
Respiration and Photosynthesis
Answer:
Differences between Respiration and Photosynthesis

Respiration	Photosynthesis
1. It is a catabolic process in which food substrates are broken down.	1. It is an anabolic process in which food substrates are synthesized.
2. It takes place in all living cells.	2. It is carried out only by the chlorophyll containing cells of plants.
3. CO2 and H2O are produced.	3. CO2 and H2O are used.
4. CO2 is given out.	4. O2 is released as a byproduct.
5. Chemical energy is converted into ATP and some energy is lost as heat.	5. Radiant energy’of light is converted into 1 chemical energy.

Question 23.
What is fermentation? How is it important?
Answer:
The slow decomposition of organic matter into simpler substances in the presence of enzymes is known as fermentation. It is a type of anaerobic respiration. Fermentation literally means a chemical change accompanied by effervescence. The anaerobic breakdown of glucose to carbon dioxide and ethanol is a form of respiration referred to fermentation. It is normally carried by yeast cells and accounts for the production of alcohol in alcoholic bevefages. In fermentation process, if glucose is converted into ethanol then it is called ethanolic fermentation. When glucose is converted into organic acids such as lactic acid, then this type of fermentation is known as lactic acid fermentation. It is carried out by the bacterium Bacillus acidilacti.

Question 24.
Briefly explain the human respiratory system and also label the parts 1, 2, 3, 4, 3 and 6.

Answer:
Human Respiratory System. Respiratory system of human beings and other mammals consists of air passage or respiratory tract, a pair of lungs.

Respiratory tract is made up of nostrils nasal cavity, pharynx, larynx, trachea and bronchi.

1. Left Lung
2. Heart
3. Diaphragm
4. Trachea
5. Larynx
6. Nasal Cavity

The lungs are a pair of brownish grey coloured spongy structures situated in the thoracic cavity. The left lung consists of two lobes while the right lung consists of three lobes.

Each lobule of a lung consists of bronchioles which terminate into a bunch of spherical thin walled air sacs, called alveoli.

Each alveolus or air sac has a diameter of 75 to 300 microns and has a very thin wall. The walls of the alveoli are elastic and are supplied with capillaries. Gases are exchanged between the capillaries and the air sacs through these thin walls.

Question 25.
What are the different modes of respiration in animals?
Answer:
In animals such as earthworm, respiration is by skin.

• The insects have an elaborate tracheal system of respiration.
• Fishes respire through gills.
• Respiratory system of human beings and other mammals consists of air passage or Respiratory tract, and a pair of lungs.
• Respiratory tract is made up of nasal cavity, pharynx, larynx, trachea and bronchi. The lungs are a pair of brownish grey coloured spongy structures situated in the thoracic cavity.
• The left lung consists of two lobes while the right lung consists of three lobes.
• Each lobule of a lung consists of bronchioles which terminate into a bunch of spherical thin-walled air sacs, called alveoli.

Question 26.
Differentiate between respiration and combustion.
Answer:
Difference between respiration and combustion.

Respiration	Combustion
1. It occurs in living cells.	1. It occurs in non living and dead cells.
2. It is a complex biochemical process controlled by several enzymes.	2. It is a chemical process.
3. Heat produced is much less.	3. A large amount of heat is produced.
4. There is no flame or light produced.	4. This process is usually accompanied with flame and light.

Question 27.
What are parasitic nutrition?
Answer:
Parasitic nutrition (Para = besides ; sitos = food). In this an organism (parasite) depends upon the organism (host) for its nutritional requirements. Many bacteria, viruses, fungi, some non-green plants and many animals have this mode of nutrition.

For example, a fungus Puccinia is a parasite on wheat and barberry plants; Cuscuta or dodder plant grows as a parasite on many plants; tapeworms and round worms are parasites in the body of man etc.

Parasites are of two kinds :

1. Ectoparasites and
2. Endoparasites

Question 28.
Differentiate between Light reaction and Dark reaction in photosynthesis.
Answer:
Difference between light reaction and Dark reaction

Light reaction	Dark reaction
1. Light reaction is light induced chemical reaction.	1. Dark reaction requires no light and is purely enzyme controlled reaction.
2. Energy rich compounds like ATP and NADPH2 are synthesized.	2. The energy rich compounds are used to produce the organic compounds.
3. Oxygen is liberated.	3. No liberation of oxygen.
4. It takes place in the grana of the chloroplasts.	4. It takes place in the stroma of chloroplasts.

Question 29.
What are the functions of liver?
Answer:
Functions of liver

1. Role in digestion. Bile produced by liver helps in the digestion of food as follows.
   • It emulsifies the fats with its salts.
   • It prevents decomposition of food by checking the growth of bacteria.
   • It neutralizes the acid coming from the stomach along with food and provide alkaline medium in the intestine required for action of enzymes of pancreas and intestinal glands.
2. Regulation of Blood Sugar: The liver separates the excess of sugar from the blood and stores it in its cells as glycogen (animals starch).
3. Formation of Glycogen from non-carbohydrates Sources.
4. Deamination: In the liver, the amino acids coming from the alimentary canal are sorted out, ammonia is formed. Ammonia is converted to less toxic urea.
5. Excretion: Liver collects haemoglobin of the worn-out red blood corpuscles and changes it into bile pigments.

Question 30.
Differentiate between Saprophytic and Parasitic nutrition.
Answer:

Saprotrophic Nutrition

Parasitic nutrition

Many organisms absorb fluid food through the body surface. This is called saprotrophic nutrition. Bacteria and fungi flourish on dead, decaying organic matter of both plant and animal origin. They secrete digestive enzymes onto this matter. The enzymes hydrolyze the organic matter into simple soluble products that are then absorbed. This method of taking up organic food is known as saprophytic nutrition.

The organisms obtain nutrients from a living host without helping it any way. Examples. Liver fluke lives in the bile duct of sheep and absorbs nutrient. Other examples include several fungi, bacteria and a few higher non-green plants such a cuscuta.

Question 31.
Discuss the fate of food in the oral cavity of man.
Answer:
Fate of food in mouth cavity. The partial digestion of food occurs due to the action of Ptyalin enzyme. It acts on starches and forms maltose.
The sufficiently masticated, partially digested food forms bolus. It is swallowed into oesophagus through gullet by raising the throat aided by the muscles of pharynx.

Question 32.
What is a digestive gland? Name the various digestive glands of man and their secretions.
Answer:
Digestive gland. A gland that secretes digestive juice which is helpful in the digestion of food is called a digestive gland.

Digestive glands of Man

Name of digestive gland	Name of digestive juice/Secretion
1. Salivary gland	Saliva
2. Gastric glands	Gastric juice
3. Pancreas	Pancreatic juice
4. Liver	Bile
5. Intestinal glands	Intestinal juice

Question 33.
Write the enzymes of the pancreatic juice, the substrates they digest and the products of their digestive action.
Answer:
Enzymes of the pancreatic juice

Name of Enzyme	Substrate	Name of end products
1. Amylase	Starch, glycogen	Maltose and Isomaltose
2. Trypsin	Proteoses, Peptones and Proteins	Peptides and amino acid
3. Lipase	Emulsified lipids	Glycerol and fatty acids

Question 34.
What is meant by photosynthesis? What are the basic requirements for the process of photosynthesis?
Answer:
The manufacture of organic compounds from carbon dioxide and water in the presence of sunlight inside the chlorophyll containing cells of the plant is called photosynthesis. The overall reaction of photosynthesis is

Basic requirements for photosynthesis. CO2, water, chlorophyll and solar energy. Photosynthesis is a photo-biochemical process in which energy rich compounds such as carbohydrates (glucose) are synthesized from simple inorganic compounds like CO2 and water in the presence of sunlight and chlorophyll. Oxygen is a by-product.

Question 35.
What are the different ways in which glucose is oxidized to provide energy in various organisms?
Answer:
Breaking down of glucose involves two step process. In the first step, it is broken into three carbon molecule called pyruvate. The pyruvate is further broken down into energy in following different ways in various organisms :

• Aerobic Respiration: In this case, pyruvate is broken down into water and carbon dioxide along with release of energy. It commonly occurs in mitochondria of cells.
• Anaerobic Respiration in Yeast: In yeast cells during fermentation pyruvate is converted into ethanol and carbon dioxide in the absence of oxygen.
• Anaerobic Respiration in Muscles: Due to lack of oxygen, e.g. during vigorous running or exercise, in human muscles, pyruvate is converted into lactic acid.

Question 36.
Explain how exchange of materials takes place between Blood and Tissues.
Answer:
Arteries supply fresh blood with 02 and food materials to different body organs. Inside the body organ the artery divides into smaller branches called arterioles. The arterioles further divide into extremely thin walled blood capillaries. The blood capillaries form an extensive network inside the body organ. They make their way through the tissue cells. Blood plasma along with the dissolved materials comes out of the thin walls of the blood capillaries and collects into the tissue. It is then called tissue fluid, which acts as an intermediate medium between blood and tissue cells.

The tissue fluid contains different materials such as oxygen, amino acids, glucose, mineral ions and proteins etc. which are needed by the body cells. The body cells take up the required materials from the tissue fluid and release their wastes such as C02 and nitrogenous wastes. These enter through the blood capillary wall and dissolve into the blood plasma or enter into the red blood cells and are carried away.

Question 37.
Outline inhalation-exhalation cycle.
Answer:

• Inhalation: Lowering of diaphragm → Rising of rib cage → Gas (O₂) passes to Alveoli
• Exhalation: Air is forced out → Rising of diaphragm → Lowering of ribcage

Question 38.
Leaves of a healthy potted plant are coated with vaseline to block the stomata. Will this plant remain healthy for long? State three reasons to support your answer.
Answer:
No, the plant will not remain healthy because no exchange of gases will take place. It will lead to :

• low respiration
• no photosynthesis occurs
• no transpiration.

Hence plant will not remain healthy and may die eventually.

Question 39.
What are
(i) stomata and
Answer:
Stomata are tiny apertures found on the surface of the leaf, which regulate the exchange of respiratory gases and transpiration.

(ii) lenticels?
Answer:
Lenticels are the raised pores in the woody plants that allow the exchange of gases between the atmosphere and the internal tissues.

Question 40.
Briefly explain breathing, external resperation exchange of gases and tissue resperation.
Answer:

• Breathing involves inhaling of oxygen rich fresh air and exhaling of carbon dioxide rich foul air. The respiratory surface is richly supplied with blood for this purpose. Oxygen of the inhaled air is taken up by blood while carbon dioxide of the blood passes into the air for exhalation.
• The exchange of gases between the blood and the air at the respiratory surface is. known as external respiration.
• Oxygen absorbed by the blood at the respiratory surface is taken to various parts of the body through arteries. Blood loses the oxygen contained in it to tissue fluid, from where it picks up carbon dioxide. The latter is brought to the respiratory surface by blood.
• Tissue respiration, also called internal respiration, is the exchange of gases between the tissue cells and the blood involving uptake of oxygen by tissue cells, oxidation of respiratory substrate and elimination of carbon dioxide by the cells.

Question 41.
Why is mitochondria termed ‘power house’ of the cell?
Answer:

• Most of the aerobic respiration occurs inside the mitochondria and therefore, the latter are also called power houses of the cells.
• Mitochondria are site of synthesis, storage and transport of ATP.
• ATP (Adenosine triphosphate) is the energy currency of the living organisms.
• Adenosine triphosphate. The energy released during cellular respiration is immediately used to synthesise a molecule called ATP from ADP and inorganic phosphate

ATP is used to fuel all other activities in the cell. Therefore, it is said to be the energy currency for . most cellular processes.

Question 42.
The figure shows different ways in which glucose is oxidised to provide energy in various organisms?
Fill up the blanks : A _________ B _________ C _________, D. _________ E _________ F _________

Answer:
Different pathways to provide energy from glucose
A. glucose
B. Pyruvate
C. Absence of Oxygen
D. Presence of oxygen
E. Lactic Acid F. Carbondioxide

Question 43.
Fill in the blanks 1, 2, 3, 4, 5, 6 in the figure.

Double circulation of blood in birds and mammals.
Answer:

1. Right vetricle
2. Lungs
3. Left Auricle
4. Left Ventricle
5. Body parts (except Lungs)
6. Right Auricle

Question 44.
State differences between artery and vein.
Answer:
Differences between Artery and Vein

Artery	Vein
1. An artery carries blood from the heart to different organs of the body.	1. A vein collects blood from different organs of the body and brings it back to the heart.
2. Blood flows under great pressure.	2. Blood flows under less pressure.
3. It has a thick muscular wall.	3. Wall is thin
4. It is non collapsible.	4. It is collapsible.
5. It contains oxygenated blood (Exception pulmonary artery).	5. It contains deoxygenated blood (Exception pulmonary vein)
6. Valves are absent.	6. Valves are present.
7. Mostly deep seated.	7. Mostly superficial.

Question 45.
Why are WBCs called ‘soldiers of the body’?
Answer:
WBC (White Blood Corpuscles) or leucocytes engulf and destroy the foreign particles in the body. Hence they are called ‘soldiers of the body.’

Question 46.
What are hypertension and hypotension?
Answer:
Hypertension. It is the high blood pressure which is caused due to emotions such as worry, excitement, fear etc.
Hypotension. It is the low blood pressure when it falls below the normal level.

Question 47.
Name the three major types of blood vessels. Explain briefly.
Answer:
The three main types of blood vessels are :

• Arteries have thick elastic walls and their diameter may be even 1 cm. These blood vessels carry the blood from the heart to the various parts of the body.
• Capillaries. Arteries divide into thin arterioles and arterioles further ramify into capillaries (1 micron diameter). The wall of a capillary is made up of a single layer of cells. The muscles and elastic fibres are absent in the capillaries. The walls of these capillaries are so thin that the exchange of food materials, waste materials and gases takes place between the blood and protoplasm of cells (liver, lung etc.) through them.
• Veins. The capillaries again reunite to form venules and venules unite to form veins. These venules and veins return the blood to the heart.

Diagram showing the relationship among blood vessels

Question 48.
Write a note on lymphatic system in human beings.
Answer:
Lymphatic system: The lymphatic system comprises colourless fluid, the lymph; a network of fine channels, the lymphatic capillaries; tubes of varied sizes, the lymphatic vessels; and the lymph nodes. Tissue or interstitial fluid present in the spaces between tissue cells is formed by filtration of protein-free fluid from the blood. Tissue fluid passes into lymphatic capillaries to form lymph. The latter is carried by lymphatic vessels to the veins. Lymphatic vessels have lymph nodes which filter lymph, removing microorganisms and cellular debris and adding lymphocytes.

Question 49.
Write functions of lymph.
Answer:
Functions of lymph

• It drains excess tissue fluid from the extracellular spaces back into the blood.
• Some of the fluid from the digestive tract is absorbed in the lymph. The lymphatic vessels store this fluid temporarily, and release it gradually so that the kidneys do not face a sudden pressure of urine excretion.
• It carries carbon dioxide and nitrogenous waste materials that diffuse into the tissue fluid to the blood.
• It takes lymphocytes and antibodies from the lymph nodes to the blood.

Question 50.
Give differences between blood and lymph.
Answer:
Differences between Blood and Lymph

Blood	Lymph
1. It consists of plasma, erythrocytes, leucocytes and platelets.	1. It consists of plasma and leucocytes (lymphocytes most abundant).
2. It is red in colour due to the presence of haemoglobin in erythrocytes.	2. It is colourless as haemoglobin is absent,
3. Its plasma has more proteins, calcium and phosphorus.	3. Its plasma has fewer proteins and less calcium and phosphorus.
4. It transports materials in the body.	4. It acts as middle man between blood and body tissue.

Question 51.
How are xylem and phloem well suited for transport of materials in plants? Explain.
Or
How are water and mineral transported in plants?
Answer:
Xylem and phloem are well suited to carry water, minerals and food in plants. Vessels in the xylem are cylindrical in shape with their ends open and are placed one above the other so as to form a continuous column stretching from roots to leaves. So, the water and minerals absorbed by the roots are carried upwards to the leaves. This is known as transportation.

Similarly, phloem has sieve tubes that are also cylindrical but the ends are not open instead covered with sieve (perforated) plate. These tubes are also placed one above the other, forming a continuous column from leaves to other parts of the plant body. The food synthesized in the leaves is carried to other paxts of the plant body through phloem. Sucrose is the main form in which carbohydrates are translocated in plants.

Xylem vessels that transport water and mineral sahs

Phioem tubes that conduct prepared food.

Question 52.
Mention any three methods adopted by plants to minimise the transpiration rate.
Answer:
Three methods adopted by plants to minimise the rate of transpiration are :

1. In some cases leaves are rolled to cover stomata (e.g. some grasses)
2. The stomata may be sunken (e.g. Nerium)
3. In some cases, leaves may be dropped or absent as in most cacti.

Question 53.
Write a short note on root pressure.
Answer:
Root pressure: During absorption, water is forced into the xylem vessels by the surrounding cortical cells with a certain force. This induces a pressure which is responsible for ascent of sap to many feet in xylem. This pressure which is developed due to the activity of root is called as root pressure.
Root pressure is a vital phenomenon and depends upon the activity of living root cells. The magnitude of root pressure varies from 2-8 atm.

Question 54.
How is transpiration useful to plants?
Answer:
Advantages of transpiration

• It has cooling effect on the plants as excess of sun’s energy is dissipated.
• It helps in the removal of excess of water from the plant.
• It causes ascent of sap.
• It helps to maintain water cycle.
• It increases the amount of sugar and mineral content in the fruit.
• It is needed to permit photosynthesis to take place.

Question 55.
What are the disadvantages of transpiration?
Answer:

• More plants die from excessive water loss by transpiration.
• Due to high rate of transpiration plants suffer from loss of turgidity.

Question 56.
What is translocation?
Answer:
Translocation: The long distance transport of the organic food from a source to a sink is known as translocation.

Question 57.
(a) What is blood pressure?
Answer:
Blood pressure is the force that blood exerts against the wall of a vessel. This pressure is much greater in arteries than in veins. The pressure of blood inside the artery during ventricular systole is called systolic pressure and pressure in artery during ventricular diastole is called diastolic pressure.

(b) What are normal value of systolic and diastolic blood pressure
Answer:
The normal systolic pressure is about 120 mm of Hg and diastolic pressure is 80 mm of Hg.

(c) How is it measured?
Answer:

Measurement of blood pressure

(d) Name the instrument used to measure blood pressure.
Answer:
Blood pressure is measured with an instrument called sphygmomanometer.
High blood pressure is also called hypertension and is caused by the constriction of arterioles, which results in increased resistance to blood flow. It can lead to the rupture of an artery and internal bleeding.

Question 58.
Write a note on mechanism of blood clotting.
Answer:
Blood Clotting: At the site of injury, blood platelets disintegrate and release enzyme thromboplastin. Thromboplastin in the presence of calcium ions, transforms the inactive prothrombin into active thrombin. Thrombin converts soluble fibrinogen into insoluble fibrin. This forms a meshwork of fibrils which entangle blood corpuscle and transforms the liquid blood into a gel or clot.

Mechanism of Blood Clotting
Unless the blood clots at the site of the injury, there will be loss of blood (blood haemorrhage).
Such a loss of blood will lead to death of the person.

Question 59.
Briefly describe excretory system.
Answer:

• Kidneys are a pair of bean-shaped reddish brown organs which lie in the lumbar part of abdomen along the dorsal wall, one on either side of the vertebral column.
• Each kidney receives a renal artery from dorsal aorta and sends a renal vein to inferior vena cava.
• The excretory waste products ,are filtered out in the kidney.
• Each kidney contains about 1.2 million excretory units called uriniferous tubules or nephrons.
• Uriniferous tubule is a long, twisted, narrow, tubular structure which consists of ‘ Bowman’s capsule, neck, proximal convoluted tubule, loop of Henle and distal convoluted tubule.
• Bowman’s capsule is a blind cup-shaped end of uriniferous tubule with a tuft of blood capillaries called glomerulus.
• Ureters are two distensible tubes which connect the kidneys with the urinary bladder.
• Urinary bladder is a median pear-shaped bag-like structure that occurs in she pelvic region of abdominal cavity.
• Urinary bladder can hold 300-800 ml of urine.
• Urethra is a tubular connection between the urinary bladder and the external Opening of urinary tract.

Question 60.
Label the parts of human excretory system.
Answer:

1. Kidney
2. Ureter
3. Urinary Bladder.

Question 61.
How does the excretion take place in Amoeba?
Answer:
The excretory product of Amoeba is ammonia. Special excretory organelle is lacking in Amoeba. C02 and ammonia are excreted by diffusing in solution through plasma membrane. The concentration of ammonia is always higher in Amoeba than in the surrounding water. The water enters through plasma membrane by “endosmosis”. Ammonia is formed in cytoplasm by metabolism.

Surplus water enters contractile vacuole. This surplus water can rupture the animal’s body. Thus size of contractile vacuole increases, when the contractile vacuole is fully expanded with water, it moves towards the periphery. As the contractile vacuole comes in close contact with the plasma membrane, it bursts. Thus excess of water (surplus water) is discharged in the surrounding water. This phenomenon of controlling the amount of water in the body is called as “osmoregulation”.

Excretion in Amoeba

Question 62.
State one main function of the following :
(i) Glomerulus
Answer:
The filtration of blood in the nephron takes place in the glomerulus.

(ii) Malpighian capsule
Answer:
Malpighian capsule is concerned with ultrafiltration.

(iii) Sweat gland
Answer:
Sweat glands produce sweat containing urea, uric acid and salts. Sweat evaporates to bring down the body temperature to normal.

(iv) Nephron of kidney tubule
Answer:
Through the kidney tubule or nephrons, filtration of urea, uric acid, water and some salts occur from the blood.

(v) Loop of Henle.
Answer:
Loop of Henle is useful in the absorption of water and secretion of urea.

Question 63.
Name the chief organs of excretion in man. Mention the waste products that they excrete.
Answer:
The chief excretory organs and the waste products removed by them are :

1. Kidneys – Urea in the form of urine.
2. Lungs – Carbon dioxide.
3. Skin – Water and salts as sweat.

Question 64.
Name the following :
(i) A process by which the unwanted nitrogenous wastes are eliminated from the body.
Answer:
Excretion

(ii) Major excretory organs of man.
Answer:
Kidneys

(iii) The structural and functional units of kidney.
Answer:
Nephrons

(iv) A tuft of blood capillaries found in the Bowman’s capsule of nephron.
Answer:
Glomerulus

Question 65.
Name the following :
(i) The structure that brings urine from the kidney to the urinary bladder.
Answer:
Ureter

(ii) Thin membranous sac serving as the reservoir of urine.
Answer:
Urinary bladder

(iii) Any two organic constituents of normal human urine.
Answer:
Urea, creatinine

(iv) The chief nitrogenous waste product in the human urine and the organ which produces it.
Answer:
Urea, liver

(v) Name two excretory products formed by the liver.
Answer:
Bile pigments (Bilirubin, Biliverdin), urea.

Question 66.
What do you understand by artificial kidney? Name the principle on which it works.
Or
Write a note on haemodialysis.
Answer:
Artificial Kidney or Haemodialysis. In case of acute kidney failure, the poisonous materials may accumulate in the body fluids which will cause oedema and finally lead to death of the patient. In such cases, artificial kidney is used. It works on the principle of dialysis and separates wastes from the blood. The process is called haemodialysis.

Artificial kidney contains a number of tubes with a semipermeable lining.
Its functioning is similar to kidney, but it is different since there is no reabsorption involved.

In this, blood from an artery is diverted through a cellophane tube, having pores equal to those of glomerular capillaries, placed in a circulating bath. Concentration of bath-fluid is kept equal to that of normal plasma. The pores in the cellophane tube allow small sized wastes like urea, ammonium salts etc. to pass through but do not allow the passage of blood cells, proteins, fats etc. Diffusion of small and useful substances like glucose, amino acids etc is prevented by keeping their concentration in the dialysis fluid equal to the normal plasma. Blood from dialyser is returned to the body through a vein.

Flow of blood through an artificial kidney for haemodialysis.

Question 67.
What are the functions of tongue?
Answer:
Functions of tongue.

• It helps in mastication of food.
• It bears taste buds and helps in the sensation of taste of food.
• It takes part in the modification of sound production.
• It acts as a brush and cleans the teeth.
• It aids in deglutition of food.

Question 68.
(i) Label the part A-E
Answer:

A. Interventricular System B. Right Ventricle C. Right Atrium D. Left Ventricle E. Aorta

(ii) Write Function of E.
Answer:
Function of E-Aorta carries blood to all parts of body.

Very Short Answer Type Questions

Question 1.
Why are maintenance processes required?
Answer:
They are required to prevent breakdown.

Question 2.
List three characteristics of living organisms.
Answer:

1. Growth
2. Movements
3. Repair and maintenance of their structures.

Question 3.
What are life processes?
Answer:
The processes which together perform the maintenance jobs are collectively termed as life processes.

Question 4.
What is the basic requirement of maintenance?
Answer:
Energy is needed by living organisms for maintenance.

Question 5.
What are sources of energy for living organisms?
Answer:
Carbon based molecules i.e. food obtained from environment.

Question 6.
List the common reactions required to obtain energy from carbon based molecules.
Answer:
Oxidising-reducing reactions.

Question 7.
Name any four life processes required for maintenance.
Answer:

1. Nutrition
2. Respiration
3. Transportation
4. Excretion.

Question 8.
What are nutrients?
Answer:
The substances which provide materials for growth, energy and maintenance are called nutrients.

Question 9.
What is nutrition? Why is it necessary?
Answer:
Nutrition. The sum total of processes by which living organisms obtain food materials and prepare them for use in the growth, repair and providing energy is termed nutrition.

Question 10.
What is food?
Answer:
Food provides energy. It Provides raw materials for growth and maintenance.

Question 11.
What is holozoic nutrition?
Answer:
Holozoic nutrition. When the nutrients are ingested as solid organic food matter, it is called holozoic nutrition.

Question 12.
What is the source of food for heterotrophs?
Answer:
All heterotrophs obtain food from autotrophs.

Question 13.
Name the process which prepares food is autotrophs.
Answer:
Photosynthesis.

Question 14.
Why are green plants called producers?
Answer:
Green plants prepare their food from CO₂ and H₂O in the presence of sunlight and chlorophyll. All other organisms obtain food from green plants, thus called as producers.

Question 16.
In which spectrum of light maximum photosynthesis occurs?
Answer:
Red light.

Question 17.
Where is chlorophyll present in cells of leaves?
Answer:
Chloroplast.

Question 18.
How does oxygen produced during photosynthesis enter the atmosphere?
Answer:
Oxygen passes out of green leaves through stomata and diffuses into the atmosphere.

Question 19.
Where does photolysis occur in plant?
Answer:
Photolysis occurs in chloroplasts present in the cell.

Question 20.
Write chemical reaction of photosynthesis.
Answer:

Question 21.
What are the advantages of cooked food?
Answer:
Human beings consume cooked food. Cooking makes it soft, palatable, tasty and easier to digest.

Question 22.
What is the role of CO₂ during photosynthesis?
Answer:
CO₂ provides carbon for synthesis of glucose (C₆H₁₂O₈) during photosynthesis.

Question 23.
What is the role of stomata in green leaves?
Answer:
Stomata are minute pores through which exchange of gas occurs.

Question 24.
Name the minerals obtained from soil by plants.
Answer:
Nitrogen, phosphorus, potassium, iron, magnesium and other minerals.

Question 25.
What is the role of nitrogen plants?
Answer:
Nitrogen is constituent of proteins and nitrogen bases of nucleic acids.

Question 26.
What is the food of Amoeba?
Answer:
Food of Amoeba consists of small protozoans, algae, rotifers, bacteria, and diatoms. It also feeds upon bits of organic matter.

Question 27.
Is food vacuole of Amoeba, temporary structure or a permanent one?
Answer:
Food vacuole is a temporary structure.

Question 28.
What is saliva?
Answer:
Saliva is a digestive juice secreted by salivary glands present in oral cavity.

Question 29.
Name the enzyme present in saliva.
Answer:
Salivary amylase.

Question 30.
Name the organ through which blood passes into stomach from oral cavity.
Answer:
Pharynx and oesophagus.

Question 31.
Name the largest part of alimentary canal.
Answer:
Small intestine.

Question 32.
Which of the animals need long large intestine?
Answer:
Animals eating grasses need large intestine for digestion of cellulose.

Question 33.
What is the nature of food entering small intestine from stomach?
Answer:
Acidic in nature.

Question 34.
Name the juices which convert acidic food into alkaline in small intestine.
Answer:
Bile and pancreatic juice.

Question 35.
Name the digestive juice secreted by liver.
Answer:
Bile juice.

Question 36.
Name the digestive juice secreted by pancreas.
Answer:
Pancreatic juice.

Question 37.
List the enzymes which help in the digestion of proteins.
Answer:

• Pepsin
• Trypsin
• Chymotryposin
• Peptidases.

Question 38.
What is approximate length of human alimentary canal?
Answer:
9 to 10 metres.

Question 39.
Name the largest gland present in human body.
Answer:
Liver.

Question 40.
Name the gland which is exocrine as well as endocrine in nature.
Answer:
Pancreas.

Question 41.
What are three parts of small intestine?
Answer:

1. Duodenum
2. Jejunum
3. Ileum.

Question 42.
Differentiate between chyme and chyle.
Answer:

• Chyme is a semisolid, semidigested acidic food which passes from stomach into duodenum.
• Chyle is emulsion form, completely digested, alkaline food present is small intestine ready for absorption.

Question 43.
Name the four enzymes present in pancreatic juice.
Answer:

1. Pancreatic amylase
2. Pancreatic lipase
3. Trypsin
4. Chymotrypsin.

Question 44.
Maximum water is absorbed in which part of alimentary canal.
Answer:
Large intestine.

Question 45.
What is digestion?
Answer:
Digestion. Chemical and mechanical break down of complex, non-diffusible form of food into simple diffusible form of food by action of enzyme.

Question 46.
What is assimilation?
Answer:
The absorption and digestion of food or nutrients by the body or any biological system.

Question 47.
What is egestion?
Answer:
The act or process of discharging undigested food as faeces from a cell in case of unicellular organisms.

Question 48.
What are villi present is small intestine and not in stomach?
Answer:
Small intestine is site of absorption of digested food, villi increase the surface area for absorption of food. No absorption of food occurs in stomach thus villi are absent.

Question 49.
What happens to pyrnvate produced during anaerobic respiration?
Answer:
Pyruvate produced at the end of glycolysis is converted to C02 and ethanol.

Question 50.
What is aerobic respiration?
Answer:
Aerobic respiration is the process of producing cellular energy involving oxygen cells break down food in the mitochondria in a long, multistep process that produces roughly 36 ATP.

Question 51.
What is anaerobic res-piration?
Answer:
A form of incomplete intracellular breakdown of sugar or other organic compounds in the absence of oxygen that releases energy.

Question 52.
What is ATP?
Answer:
ATP is Adenosine triphosphate. It is the energy currency of life. ATP is a high- energy molecule found in every cell. Its job is to store and supply the cell with needed energy.

Question 53.
Expand NADP.
Answer:
NADP. Nicotinamide Adenine Dinucleotide.

Question 54.
Name three animals which respire through skin.
Answer:

1. Earthworm
2. Leech
3. Frog.

Question 55.
Where does Krebs cycle occur in the body?
Answer:
Krebs cycle is completed in mitochondria of cells.

Question 56.
What is hypoxia?
Answer:
Hypoxia is a condition of shortage of oxygen in the body due to strangulation on cyanide poisoning.

Question 57.
Name the respiratory sub-strate.
Answer:
Glucose.

Question 58.
What is the end product of aerobic respiration?
Answer:
Carbon dioxide and water.

Question 59.
What is fermentation?
Answer:
Incomplete breakdown of glucose in the absence of oxygen in microbes such as bacteria and yeast. It forms CO2₂, ethanol and energy is released in small amount.

Question 60.
Man breaths how many times per minute?
Answer:
12-15 times.

Question 61.
What are the functions of ATP?
Answer:
ATP provide energy for all metabolic reactions in the body such as movements, synthesis, cell division.

Question 62.
What is bark?
Answer:
The tissue ontside the outer most covering of the stem or root is called bark.

Question 63.
Name the tissue which transport food in plants.
Answer:
Phloem.

Question 64.
What is xylem?
Answer:
Xylem is a complex tissue which transport water and minerals from roots to other parts of the plant.

Question 65.
Name two substances which enter the root through the root hairs.
Answer:

1. Water
2. Soluble minerals from soil.

Question 66.
What is ascent of sap?
Answer:
The process by which water absorbed by the root is carried to aerial parts of plant is called ascent of sap.

Question 67.
Name the transport tissue of body.
Answer:
Blood and lymph.

Question 68.
Name the three types of blood vessels.
Answer:

1. Arteries
2. Veins
3. Capillaries.

Question 69.
List types of circulation in human body.
Answer:
Double circulation involving pulmonary circulation and systemic circulation.

Question 70.
Name the fluid medium of blood.
Answer:
Plasma.

Question 71.
Why is the S-A node called pace-maker of the heart?
Answer:
S-A node, being self-excitatory, initiates a wave of contraction in the heart.

Question 72.
Name the organs which play role in circulation of blood.
Answer:
Heart. It is a muscular, pumping organ. It pumps the blood in the body.

Question 73.
Name the types of cells which destroy harmful bacteria in the body.
Answer:
White blood corpuscles (W.B.C.)

Question 74.
Name the instrument used to measure blood pressure.
Answer:
Sphigmomanometer.

Question 75.
Name the artery which carry impure (deoxygenated) blood from heart to lungs.
Answer:
Pulmonary artery.

Question 76.
Expand ECG.
Answer:
Electrocardiogram.

Question 77.
Write normal blood pressure in human body.
Answer:
120/80 → Systolic = 120 and Diastolic = 80

Question 78.
Name the largest artery.
Answer:
Aorta.

Question 79.
What is excretion?
Answer:
Excretion. Elimination of nitrogenous waste materials from body is called excretion.

Question 80.
How many nephrons are present in each kidney?
Answer:
About 10 lakhs.

Question 81.
What are the excretory structures of amoeba?
Answer:
Contractile vacuole.

Question 82.
What is a malpighian body (renal corpuscle)?
Answer:
Bowman’s capsule and glomerulus.

Question 83.
Name the reservoir of urine in the body.
Answer:
Urinary bladder.

Question 84.
What is micturition?
Answer:
Act of passing out of urine from urinary bladder is called micturition.

Question 85.
Name the structures which store wastes in plants.
Answer:
Central vacuoles.

Question 86.
What are resins and gums?
Answer:
These are storage wastes of plants.

Question 87.
Define autotrophic nutrition.
Answer:
The organisms prepare their own food from raw materials like C02 and H20 in the presence of sunlight. It takes place in green plants containing chlorophyll.

Question 88.
Define heterotrophic nutrition.
Answer:
The mode of taking readymade organic food material is called heterotrophic nutrition. It may be holozoic (ingestive) or saprophytic and parasitic (absorptive).

Multiple Choice Questions

Question 1.
Among the following which is a parasitic plant?
(A) Plasmodium
(B) Cuscuta
(C) Amoeba
(D) Rhizobium.
Answer:
(B) Cuscuta

Question 2.
Dark reaction and light reaction of photosynthesis takes place is:
(A) stroma and grana of chioroplast respectively
(B) grana and stroma of chioroplast respectively
(C) grana only
(D) stroma only.
Answer:
(A)stroma and grana of chioroplast respectively

Question 3.
Chemical reaction takes place during dark reaction of photosynthesis is:
(A) photo1ysi
(B) hydrolysis
(C) carbon dioxide is bonded with RUBP
(D) nitrogen fixation.
Answer:
(C) carbon dioxide is bonded with RUBP

Question 4.
Plants are green in colour because:
(A) they absorb green light only
(B) they reflect green light
(C) they absorb green light but reflect all other lights
(D) none of the above are correct.
Answer:
(B) they reflect green light.

Question 5.
The nutrition in Mucor is:
(A) parasitic
(B) autotrophic
(C) saprophytic
(D) holozoic.
Answer:
(C) saprophytic

Question 6.
In amoeba the digestion is intracellular because :
(A) amoeba is unicellular
(B) amoeba is multicellular ‘
(C) amoeba is found in pond
(D) amoeba is microscopic animal.
Answer:
(A) amoeba is unicellular

Question 7.
Which of the following has no digestive enzyme?
(A) Saliva
(B) Bile
(C) Gastric juice
(D) Intestinal juice.
Answer:
(B) Bile

Question 8.
C02 acceptor during dark reaction of photosynthesis is :
(A) RUBP
(B) PEP
(C) NADPH
(D) ATP.
Answer:
(A) RUBP

Fill in the blanks:

Question 1.
Viruses show _________ movements.
Answer:
Molecular.

Question 2.
Growth, _________ and repair and _________ are characteristics of life.
Answer:
movements, maintenance.

Question 3.
_________ is needed by living organisms for movements and maintenance.
Answer:
Energy.

Question 4.
_________ is the largest gland of body.
Answer:
Liver

Question 5.
_________ and are the raw materials for photosynthesis.
Answer:
C02 and H20.

Question 6.
RBC transport _________ in the body.
Answer:
Oxygen.

Question 7.
Xylem and _________ are the main conducting tissues in plants.
Answer:
Phloem.

Question 8.
Translocation of food takes place through _________ of phloem.
Answer:
Sieve tubes.

Punjab State Board PSEB 10th Class English Book Solutions English Main Course Book Chapter 3 Secret of Happiness Textbook Exercise Questions and Answers.

PSEB Solutions for Class 10 English Main Course Book Chapter 3 Secret of Happiness

Short Answer Type Questions

Question 1.
Which is the greatest day in an individual’s life ?
Answer:
It is when the individual begins for the first time to realize himself.

ऐसा तब होता है जब व्यक्ति सर्वप्रथम स्वयं को जानने लगता है।

Question 2.
What enthralled the student in the Psychology class ?
Answer:
The professor in the Psychology class said that an average man fails because he does not learn to control and consolidate his powers. The student was enthralled because he realized that this very thing was the cause of his own failures.

मनोविज्ञान की कक्षा में प्रोफैसर ने बताया कि एक आम आदमी इसलिए असफल होता है क्योंकि वह अपनी शक्तियों को काबू करना और उन्हें संगठित करना नहीं सीखता। इससे विद्यार्थी रोमांचित हो उठा क्योंकि उसे महसूस हो गया कि उसकी अपनी असफलताओं का यही कारण था।

Question 3.
Did the boy change as a result of realization ?
Answer:
Yes, as a result of the self-realization, the boy changed a lot. He became highly successful in his life.

हां, आत्म-ज्ञान की वजह से लड़के में भारी बदलाव आ गया। वह अपने जीवन में अत्यधिक सफल बन गया।

Question 4.
What is there in the personality of every man ?
Answer:
In the personality of every individual, there is a great reservoir of unused power.

प्रत्येक व्यक्ति के व्यक्तित्व में अप्रयुक्त शक्ति का एक भारी भण्डार होता है।

Word-meanings :

• सामना करना
• कष्ट देना, पीड़ित करना
• में विश्वास प्रकट करना।

Question 5.
How can weak personalities become strong ?
Answer:
Every individual has an immense store of unused power. By using this store, weak personalities can become strong.

प्रत्येक व्यक्ति के पास अप्रयुक्त शक्ति का विशाल भण्डार होता है। इस भण्डार का प्रयोग करने से कमज़ोर व्यक्तित्व मज़बूत बन सकते हैं।

Question 6.
What would Chesterton preach if he had just one sermon to deliver ?
Answer:
He would preach against fear and also tell the way to conquer it.

वह भय के विरुद्ध प्रवचन करता और इसे जीत पाने का रास्ता भी बताता।

Question 7.
What are the different types of fear experienced by people ?
Answer:
People experience many types of fear. There are financial fears, fears of ill health and fears about the future. There are also fears about the consequences of past acts.

लोग कई प्रकार के भय अनुभव करते हैं। वहां वित्तीय भय, बुरे स्वास्थ्य के भय और भविष्य के बारे में भय होते हैं। वहां अतीत में की गई क्रियाओं के परिणामों के भय भी होते हैं।

Question 8.
What did the author of ‘Secret of Happiness’ find when he flung the door open ?
Answer:
He found only a little chipmunk there. It ran off into the darkness as the author flung the door open.

वहां उसे केवल एक छोटी-सी गिलहरी दिखाई दी। यह तुरन्त अन्धेरे में भाग गई जब लेखक ने झटके से दरवाजा खोला।

Question 9.
How can one have a real escape from fear ?
Answer:
We must have faith in God. We must have faith that we are not alone. We must have faith that God is always with us and cares for us. Such faith can give us real peace of mind and freedom from all fear.

हमें ईश्वर में अवश्य विश्वास रखना चाहिए। हमें विश्वास रखना चाहिए कि हम अकेले नहीं हैं। हमें विश्वास रखना चाहिए कि ईश्वर सदा हमारे साथ है और हमारी चिन्ता करता है। इस तरह का विश्वास हमें मन की वास्तविक शान्ति और सब तरह के भय से मुक्ति प्रदान कर सकता है।

Question 10.
What was the priceless secret discovered by Mr. Kagawa ?
Answer:
Mr. Kagawa discovered that if a person immerses himself over a long period in the grace of God, he can attain peace that nothing can destroy.

मिस्टर कगावा ने यह बात खोज निकाली कि यदि कोई व्यक्ति एक लम्बे समय तक स्वयं को ईश्वरकृपा में डुबो लेता है तो वह ऐसी गहरी शान्ति प्राप्त कर सकता है जिसे कोई भी चीज़ नष्ट नहीं कर सकती।

Long Answer Type Questions

Question 1.
Describe, in your own words, how the professor changed the total attitude of the student.
Answer:
The student was totally unsuccessful in his studies. His professor told the class that an average man fails because he does not learn to control and consolidate his powers. The professor gave the example of the burning glass. The student realized the cause of his own failures. Thus his attitude towards life changed totally.

वह विद्यार्थी अपनी पढ़ाई में पूरी तरह से असफल रहा था। उसके प्रोफैसर ने कक्षा को बताया कि एक आम आदमी असफल रहता है क्योंकि वह अपनी शक्तियों को काबू और संगठित करना नहीं सीखता। प्रोफैसर ने जलाने वाले शीशे का उदाहरण दिया। विद्यार्थी को अपनी असफलताओं का कारण समझ में आ गया। इस प्रकार जीवन के प्रति उसका दृष्टिकोण पूरी तरह बदल गया।

Question 2.
Write a small paragraph on The Proper Use of Human Energy’.
Answer:
Every human being has an immense source of energy. But sadly, an average man uses only twenty percent of his mental power. The rest of it remains unused. If human beings learn to use their unused powers, they can face and master all circumstances. Thus through the proper use of human energy, complete peace can be attained.

प्रत्येक मनुष्य के पास ऊर्जा का विशाल स्त्रोत होता है। परन्तु दुःख की बात यह है कि साधारण आदमी अपनी मानसिक शक्ति का केवल बीस प्रतिशत ही प्रयोग करता है। इसका शेष भाग अप्रयुक्त ही पड़ा रहता है। यदि मनुष्य अपनी अप्रयुक्त शक्तियों का प्रयोग करना सीख लें, तो वे सभी प्रकार की परिस्थितियों का सामना कर सकते हैं और उन पर विजय प्राप्त कर सकते हैं। इस प्रकार मानव-शक्ति के उपयुक्त प्रयोग के द्वारा संपूर्ण शान्ति प्राप्त की जा सकती है।

Question 3.
Relate the incident of North Woods in your own words. Answer: Once the author was staying in a lonely cabin in the North Woods. The night was very dark. The author heard some noises outside his cabin. He thought there were gangsters with machine guns and pistols. But the author conquered his fear and flung the door open. He found there only a little chipmunk that at once ran off into the darkness.

एक बार लेखक नार्थ वुडज़ में स्थित एक एकान्त केबिन में ठहरा हुआ था। रात बहुत अन्धेरी थी। लेखक को अपने केबिन के बाहर कुछ आवाजें सुनाई दी। उसने समझा वहां मशीनगनों और पिस्तौलों के साथ डाकू आ गए थे। परन्तु लेखक ने अपने भय पर काबू पा लिया और झटके से दरवाज़ा खोल दिया। वहां उसे मात्र एक छोटी-सी गिलहरी दिखाई दी जो तुरन्त अन्धेरे में भाग गई।

Question 4.
Write, in brief, the message given by Mr. Kagawa.
Answer:
Mr. Kagawa said that we must have faith in God. We must have faith that God is always with us and cares for us. Such faith can give us real peace of mind and freedom from fear. Nothing can destroy such peace.

मिस्टर कगावा ने कहा कि हमें अवश्य ईश्वर में विश्वास रखना चाहिए। हमें अवश्य विश्वास रखना चाहिए कि ईश्वर सदा हमारे साथ है और वह हमारी चिन्ता करता है। इस तरह का विश्वास हमें वास्तविक शान्ति और भय से मुक्ति प्रदान कर सकता है। इस तरह की शान्ति को कोई भी चीज़ नष्ट नहीं कर सकती है।

Vocabulary and Grammar

Question 1.
Give the synonyms of :
Answer:
(a) eminent — famous
(b) adversary — enemy
(c) profound — deep
(d) poise — calmness
(e) obstacle — hindrance
(f) illustration — example
(g) futile — pointless
(h) abundant — plentiful
(i) conquer — defeat
(j) total — complete.

Question 2.
Give the antonyms of :
Answer:
(a) destroy — create
(b) opponent — companion
(c) shakable — unshakable
(d) optimism — pessimism
(g) ignorance — knowledge
(e) strength — weakness
(f) ordinary — special
(g) cautious — reckless.
(h) real — imaginary
(i) fact — fiction

Question 3.
Give one word for each of the following expressions :
Answer:
(a) psychology
(b) sermon
(c) optimist
(d) journal
(e) atheist.

Question 4.
Frame sentences to show distinction between the following pairs of words :
Answer:
1. Birth–I have been living here since my birth.
Berth-I was lucky to have a berth on the train.

2. Familiar-There was something vaguely familiar about him.
Familial-A protective familial environment has made him a dull person.

3. Gate-We drove through the palace gate.
Gait-The old man was walking with an unsteady gait.

4. Adept-He is adept at mending clocks.
Adapt-She adapted herself quickly to the new climate.

5. Mental-The experience caused him much mental suffering.
Mantle The clever minister took on the mantle of supreme power.

6. Root-Vines have very long roots.
RouteWe drove home by the shortest route.

7. Peace-After years of fighting, the people longed for peace.
Piece-He lost one of the pieces of his model engine.

Question 5.
Fill in the blanks with suitable articles :
Answer:
1. The dog is a faithful animal.
2. Tanuja is an honest girl.
3. I saw an American and a European at the market.
4. We visited the Golden Temple at Amritsar.
5. The Himalayas have many ranges.
6. I use an umbrella in the rainy season.
7. Chandigarh is the capital of Punjab.

Question 6.
Change the following sentences into passive voice :
Answer:
1. He is known to me very well.
2. My help was sought by them.
3. It is time for goodbye to be said.
4. Milk is contained in this jug.
5. Foul language should not be used.
6. I will be received by my father.
7. She was annoyed at me.

Question 7.
Fill in the blanks with the appropriate comparatives or superlatives of the adjectives given in the brackets :
Answer:
1. Milk is thicker than water.
2. The pen is mightier than the sword.
3. Ludhiana is the largest city of Punjab.
4. It is easier said than done.
5. The condition of the patient is much better now.
6. Better late than never.

Question 8.
Fill in the blanks with a non-finite:
1. He used the illustration of the burning glass.
2. The great success of life lies in putting a key into the lock and releasing that terrific power.
3. If I had only one sermon to preach, I would preach people to shun fear.
4. We allow ourselves to be made miserable by fear.
5. The person who wishes to become adept in the art of living must learn to subdue his fears.
6. I sat rooted to my chair.
7. I wanted to get out of there.
8. I found the door broken.
9. He did not learn the art of controlling his powers.
10. Having faith in God gives a lot of strength: more

Objective Type Questions

Question 1.
Which illustration was used by the professor of Psychology ?
Question
The familiar illustration of the burning glass.

Question 2.
Who declared to give sermon against fear ?
(i) Professor of Psychology
(ii) Gilbert Chesterton
(iii) Author
(iv) Kagawa.
Answer:
(ii) Gilbert Chesterton

Question 3
values are needed in the world today.
Answer:
(i) Moral

Question 4.
The author found an elephant when he flung open the door. (True/False)
Answer:
False

Question 5.
We should have faith that is always with us.
(i) God
(ii) somebody
(iii) everyman
(iv) nobody.
Answer:
(i) God

Question 6. ……….
in God gives us real peace of mind.
(i) Fear
(ii) Hatred
(iii) Faith
(iv) Anger.
Answer:
(iii) Faith

Answer each of the following in one word / phrase / sentence :

Question 1.
Who is the author of the essay, ‘Secret of Happinessf ?
Answer.
Norman Vincent Peale.

Question 2.
Which is the greatest day in man’s life ?
Answer.
When he begins to realize himself.

Question 3.
Why does an average man fail ?
Answer.
Because he has not learnt to control and consolidate his powers.

Question 4.
How much of the powers possessed by a man is used by him ?
Answer.
Only a very small part.

Question 5.
What is there in the personality of an individual ?
Answer.
A great store of unused power.

Question 6.
What does the author teach us about fear ?
Answer.
Fear should never overcome us.

Question 7.
How did a student of psychology class change himself ?
Answer.
He changed himself by self-realization.

Question 8.
How can a weak person become strong ?
Answer.
By using his large store of unused power.

Question 9.
How can we overcome fear ?
Answer.
By convincing ourselves that God is always with us.

Question 10.
What was the message given by Mr Kagawa ?
Answer.
He advised us to have faith in God.

Complete the following :

1. Man’s greatest day is when he starts ………… himself.
2. Man fails because he fails to ………… his desires.
3. We can have a real escape from fear when we have faith in …………
4. The ways of destiny are …………
5. Man can succeed if he can bring his unused powers to a …………
6. An average man uses only about ………… per cent of his mental capacity.
Answer:
1. realising
2. control
3. God
4. strange
5. focus
6. twenty.

Write True or False against each statement :

1. A man feels great when he starts realizing himself.
2. The college student mentioned in the essay was no good in the athletic field.
3. We can get over our fears if we have faith in God.
4. An average human uses about 60 percent of his mental powers.
5. Fear is one of the commonest enemies of man.
6. A fear is, in many ways, like a ghost.
Answer:
1. True
2. False
3. True
4. False
5. True
6. True.

Choose the correct option for each of the following :

Question 1.
Destiny has its own ………………… ways.
(a) strange
(b) predictable
(c) funny
(d) horrible.
Answer:
(a) strange

Question 2.
We can escape fear by ………….
(a) arming ourselves
(b) self-confidence
(c) having faith in God
(d) none of the above.
Answer:
(c) having faith in God

Question 3.
The only sermon of Chesterton would be against
(a) war
(b) greed
(c) love
(d) fear
Answer:
(d) fear

Question 4.
In many respects, fear is comparable to a …..
(a) professor
(b) teacher
(c) preacher
(d) ghost.
Answer:
(d) ghost.

Secret of Happiness Summary & Translation in English

Secret of Happiness Introduction:

In this chapter, the author tells us how we can gain success in our life. He says that we should realize our powers. He says that an average man uses only twenty percent of his mental powers. Every man has a big store of unused powers. If he can use this power, he will be able to master all circumstances. Fear is one of the biggest enemies of man. If we wish to become adept in the art of living, we must learn to conquer our fears. We should have faith in ourselves. If we have faith in ourselves, we can be free from every fear. And then we shall have total peace of mind.

Secret of Happiness Summary & Translation in English

Page 31.

Dynamics of Self-Realization

The greatest day in any individual’s life is when he begins for the first time to realize himself. It happened to a college student friend of mine once with dramatic suddenness. He was as unsuccessful in his studies as he was efficient upon the athletic field. Destiny, however, has its own strange ways. One day in a class in Psychology, our student friend suddenly became enthralled as the professor described how the average man fails because he does not learn to control and consolidate his powers. He used the familiar illustration of the burning glass. The rays of the sun, falling upon a piece of paper, have little effect. Let them, however, be drawn by the burning glass to a focus and they create an intense heat which will quickly burn a hole in the paper.

The professor pointed out that the man who succeeds is the one who can draw his dissipated and therefore futile powers to a focus . Our student said that in a flashing illumination he saw the cause of his own failure and oblivious of all in the room and under the spell of a veritable new birth leaped to his feet, crying, “I see it; I see it.” What had happened ? He had met himself, a new self, his real self, which he never before had seen and the revelation changed him from a failure to a potential success, the possibilities of which were later abundantly realized. He was now a grand success in whatever he chose to do.

(Page 32)

You Are Greater than You Think.

In his famous address on ‘The Energies of Men’, William James, a geat psychologist, said, “Men habitually use only a small part of the powers which they possess and which they might use under appropriate circumstances.” A scientist is reported recently to have said that the average man uses but twenty percent of his brain power. When you think of some people, that sounds like optimism. Think of it – you are using, if you are an average person, only one fifth of your mental capacity.

Consider what you could make of life if you increased that by only fifty percent. In the personality of every individual there is a great reservoir of unused power. But in many of us just a miserable little trickle is getting through, and on that we live and do our work. The great secret of life is to put a key into the lock, turn back the sluice gates and let that power, like a terrific stream, flow into your mind and personality. It will transform you into a person of strength and effectiveness,well able to meet and master all circumstances. The important thing to emphasize is that it is a source of inward power by which weak personalities can become strong; divided personalities can become unified; hurt minds can be healed; and the secret of peace and poise attained.

The Escape from Fear
A British publishing house issued, some years ago, a volume of sermons, under the title, If I Could Preach Only Once. One of these sermons was by Gilbert Chesterton, “If I had only one sermon to preach,” Chesterton declared, “it would be sermon against fear.”

(Page 33)

Why should this eminent man of letters 11 single out so ordinary an adversary? First of all, because fear is one of man’s most common enemies. It touches every one of us in some way. Many people, for example, have financial fears. We have fears of ill health, anticipating the direful consequences of being overtaken by some bodily affliction. We allow ourselves to be made miserable by fear of what the future holds or fears of the consequences of past acts and decisions. Fears of one kind and another haunt us and cast a shadow over our happiness.

No person is at his best or in full control of his powers if he is the victim of fear. In many ways fear lays its paralyzing hand upon an individual and becomes a chief obstacle to the full development of personality and to the achievement of success in life. The person who wishes to become adept in the art of living must learn to conquer and subdue his fears.

This is a problem common to us all, and I want to state at the outset the encouraging fact that any and every individual can escape from fear. Remember this, however, only you can conquer your fears. Others may help you but ultimately you must do it yourself. The first step and, for that matter, a large part of the campaign against one’s fears is to get a complete and thorough. going knowledge of them. Bring them out into the light of day and watch them shrivel up.

A fear is not unlike a ghost. It frightens you in the gloom, but there isn’t much to it when you get it into the light. Most of the things one fears never happen; at least they do not amount to anything. As one frog in a pond may sound like a hundred when one is trying to sleep, so one little fact may be enlarged by mental fear and distorted imaging out of all proportion to its real size.

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Once in a lonely cabin1 on a dark night, deep in the North Woods, I heard on the porch noises that sent a shiver up my spine. It sounded like the cautious approach of several intruders. I sat transfixed , rooted to my chair, with every hair seemingly standing on end. Newspaper accounts of a recent murder in that section flashed across my mind. This is the end, I thought, but I was far from being prepared to die. I didn’t want to die; I wanted to get out of there.

Finally, unable to stand the suspense longer and desperation lending bravado,leaped to the door and flung it open, expecting to see a whole array of gangsters with machine guns and pistols. Instead, a little chipmunk scurried off into the darkness, leaving me limp and mortified but yet the learner of a great lesson, namely, that it is very salutary to get a good look at your fears, and that when you do, they are much less impressive than you had imagined them to be.

Faith in God

A great Japanese, Kagawa, a preacher and social worker, once visited our country. Everyone noted that he carried about himself a sense of peace and poise, an inner strength and confidence that was truly remarkable. Kagawa had discovered a priceless secret, and he gave us his secret by saying, that if one will do as he did, ‘immerse oneself over a long period in the grace of God’, one will enter into a profound calm that nothing can destroy. Kagawa said that encountering mobs, threatened by soldiers, hurt by opponents, the calm never left him. His eyesight was threatened; disease afflicted him; but he never lost his calm. He testified that he was often amazed by the depth of this peace. This he assured us he had found in God. In that relationship he lost all his fears.

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There is the real escape from fear. Get a deep, unshakable faith in the fact that you are not alone, but that God watches over you and cares for you and will bring you through all difficulties. Then you will have total peace of mind. Confidence, not fear, will be yours forever.

Secret of Happiness Summary & Translation in Hindi

Secret of Happiness Introduction:

इस अध्याय में लेखक हमें यह बताता है कि हम जीवन में सफलता कैसे प्राप्त कर सकते हैं। वह कहता है कि हमें अपनी शक्तियों को समझना चाहिए। वह कहता है कि एक आम आदमी अपनी मानसिक शक्तियों का केवल बीस प्रतिशत प्रयोग करता है। प्रत्येक मनुष्य के पास अप्रयुक्त शक्ति का एक बड़ा भण्डार होता है। वह यदि उस शक्ति का प्रयोग कर पाए तो वह हर प्रकार की परिस्थिति पर काबू पा सकता है। डर मनुष्य के सबसे बड़े शत्रुओं में से एक है। यदि हम जीने की कला में कुशल होना चाहते हैं तो हमें अपने भयों पर काबू पाना सीखना चाहिए। हमें स्वयम् पर विश्वास होना चाहिए। यदि हमें स्वयम् पर विश्वास होगा तो हम हर प्रकार के भय से मुक्त हो सकेंगे। और तब हमारे मन को पूर्ण शान्ति मिलेगी।

Secret of Happiness Summary & Translation in Hindi

आत्मज्ञान का गति-विज्ञान

किसी भी व्यक्ति के जीवन का महानतम् दिन वह होता है जब उसे पहली बार आत्मज्ञान होने लगता है। ऐसा एक बार मेरे एक मित्र के साथ, जो कॉलेज का विद्यार्थी था, नाटकीय ढंग से अचानक हुआ। वह अपनी पढ़ाई में उतना ही असफल था जितना वह खेल-कूद के मैदान में कुशल था। किन्तु भाग्य के अपने ही विचित्र ढंग होते हैं। एक दिन मनोविज्ञान की कक्षा में मेरा वह विद्यार्थी-मित्र रोमांचित हो उठा जब प्रोफैसर ने बताया कि एक औसत व्यक्ति इसलिए असफल रहता है क्योंकि वह अपनी शक्तियों पर नियंत्रण करना और उन्हें मजबूत करना नहीं सीखता।

उसने जलाने वाले शीशे वाले सुपरिचित उदाहरण का प्रयोग किया। कागज़ के एक टुकड़े पर पड़ती हुई सूर्य की किरणों का कोई प्रभाव नहीं होता। किन्तु यदि जलाने वाले शीशे द्वारा उन्हें केंद्रित कर दिया जाए तो उनसे तीव्र ताप पैदा हो जाता है जो उस कागज़ में जल्दी ही जला कर एक छेद बना देगा। प्रोफैसर ने बताया कि एक सफल व्यक्ति वही होता है जो अपनी कमज़ोर हो चुकी, और इस प्रकार बेकार पड़ी, शक्तियों को केंद्रित कर सकता है। हमारे उस विद्यार्थी ने कहा कि एक चौंधिया देने वाले ज्ञान-प्रकाश में उसने अपनी स्वयं की असफलता को पहचान लिया,और कमरे में बैठे सभी व्यक्तियों के प्रति पूरी तरह से अनजान हुआ और अपने उस नए जन्म से सम्मोहित हुआ, वह उछल कर अपने पांवों पर खड़ा हो गया और चिल्लाते हुए बोला, “मैं समझ गया; मैं समझ गया।”

क्या हुआ था? उसका स्वयं से मिलन हो गया था, एक नए व्यक्तित्व से, उसके वास्तविक व्यक्तित्व से, जिसे उसने पहले कभी नहीं देखा था और उस रहस्योद्घाटन ने उसकी असफलता को संभावित सफलता में परिवर्तित कर दिया, और जिसकी संभावनाओं को बाद में पर्याप्त रूप से अर्जित कर लिया गया। अब वह प्रत्येक उस काम में भारी सफलता प्राप्त करता जो भी वह करने का मन बनाता।”

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आप उससे अधिक महान है जितना आप सोचते हैं-‘व्यक्तियों की शक्तियाँ’, इस विषय पर दिए गए अपने प्रसिद्ध भाषण में महान् मनोवैज्ञानिक विलियम जेम्ज़ ने कहा, “लोग आदतन उन शक्तियों का एक छोटा-सा अंश ही इस्तेमाल करते हैं जो उनके पास होती हैं और जिन शक्तियों का इस्तेमाल वे शायद उपयुक्त परिस्थितियों में कर सकते हैं।” किसी वैज्ञानिक ने हाल में ही कहा था कि एक औसत व्यक्ति अपने मस्तिष्क की शक्ति के केवल बीस प्रतिशत का ही इस्तेमाल करता है। जब आप कुछ व्यक्तियों के बारे में विचार करते हैं तो यह बात एक आशावाद के जैसी लगती है। तनिक सोचिए – यदि आप एक औसत व्यक्ति हैं तो आप अपने मानसिक सामर्थ्य का केवल पांचवां भाग ही इस्तेमाल कर रहे हैं।

यह सोचिए कि आप अपने जीवन को कैसा बना सकते यदि आप उस अंश को केवल पचास प्रतिशत बढ़ा लेते। प्रत्येक व्यक्ति के व्यक्तित्व के अंदर बिना इस्तेमाल की गई शक्ति. का एक महान् भंडार होता है। किन्तु हम में से अनेकों में उस भंडार की मात्र एक हल्की-सी टपकन ही निकल रही होती है, और उसी पर हम जीवित रहते हैं और अपना काम चलाते रहते हैं। जीवन| का महान् रहस्य यही है कि आप ताले में चाबी डालें, जल-द्वारों को खोलें और उस शक्ति को एक शक्तिशाली| प्रवाह की भांति अपने मस्तिष्क और व्यक्तित्व के अंदर बह कर आने दें। यह आप को एक शक्तिशाली और प्रभावी व्यक्ति में बदल देगी जो सब परिस्थितियों का सामना करने और उन पर स्वामित्व स्थापित करने में पूरी तरह समर्थ होगा। वह महत्त्वपूर्ण बात जिस पर बल देने की ज़रूरत है, यह है कि आंतरिक शक्ति का यह एक स्त्रोत है जिससे कमजोर व्यक्तित्व शक्तिशाली बन सकते हैं, विभक्त व्यक्तित्व एकीकृत हो सकते हैं, चोट खाए मस्तिष्कों को राहत मिल सकती है, और शांति और मानसिक संतुलन के रहस्य का भेद जाना जा सकता है।

भय से छुटकारा

कुछ वर्ष पूर्व एक बर्तानवी प्रकाशन संस्थान ने प्रवचनों की एक पुस्तक जारी की जिसका शीर्षक था- यदि मैं केवल एक बार भी प्रवचन कर पाता। इन प्रवचनों में से एक प्रवचन गिल्बर्ट चेस्टर्टन की रचना थी। “यदि मेरे पास देने को केवल एक प्रवचन होता,” चेस्टर्टन ने ऐसा कहा, “तो यह भय के विरुद्ध एक प्रवचन होता।”

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इस प्रसिद्ध विद्वान ने भय जैसे एक साधारण शत्रु को क्यों चुना? सर्वप्रथम इसलिए क्योंकि भय मनुष्य के सबसे सामान्य शत्रुओं में से एक होता है। यह हममें से प्रत्येक को किसी न किसी रूप में प्रभावित करता है। उदाहरण के रूप में बहुत से लोगों को वित्तीय भय होते हैं। हमें खराब स्वास्थ्य के भय होते हैं, किसी शारीरिक कष्ट से ग्रस्त होने के खतरनाक परिणामों का हम पूर्वानुमान लगाने लगते हैं। हम स्वयं को उस भय से दुःखी बना लेते हैं कि भविष्य में क्या होगा, अथवा उस भय से कि हमारे अतीत के काम और निर्णयों के क्या परिणाम होंगे।

एक या दूसरी किस्म के डर हमें निरन्तर सताते रहते हैं और हमारी प्रसन्नता को ग्रसित करते रहते कोई भी व्यक्ति अपने सर्वोत्तम स्वरूप में नहीं होता अथवा अपनी शक्तियों पर पूरे नियंत्रण की स्थिति में| नहीं होता यदि वह भय का शिकार हो। कई तरह से भय एक व्यक्ति पर अपना अशक्त बना देने वाला हाथ रख देता है और उसके व्यक्तित्व के संपूर्ण विकास में और उसके जीवन में सफलता प्राप्त करने में एक मुख्य बाधा बन जाता है। वह व्यक्ति जो जीने की कला में दक्ष बनने की इच्छा रखता है, उसे अपने भयों पर विजय पाना और उन्हें दबाए रखना सीखना होगा।

यह हम सभी के लिए एक समस्या है और मैं शुरू में ही यह उत्साहवर्द्धक तथ्य बता देना चाहता हूं कि कोई भी और हर कोई भय से छुटकारा पा सकता है। किन्तु यह याद राखए कि केवल आप हा अपन भया पर विजय पा सकते हैं। अन्य व्यक्ति यद्यपि आप की सहायता करें, किन्तु अंत में आप को यह काम स्वयं ही करना होगा। पहला कदम और वास्तव में भी किसी भी व्यक्ति द्वारा अपने भयों के विरुद्ध अभियान का एक मुख्य अंश यह होता है कि वह उन भयों के विषय में सम्पूर्ण और गहरी जानकारी प्राप्त करे।

उनको दिन की रोशनी में लेकर आइए और फिर उन्हें मुरझाता हुआ और कुम्हलाता हुआ देखिए। भय किसी भूत से भिन्न नहीं होता है। यह आप को अंधेरे में डराता है, किन्तु जब आप इसे प्रकाश में ले कर आते हैं तो इसमें अधिक कुछ भी नहीं रहता। अधिकतर चीजें जिनसे व्यक्ति डरता है, वे कभी घटित नहीं होती हैं; कम से कम उनका कोई सार नहीं होता है। जिस तरह किसी तालाब में एक मेढक की टर्राहट सौ मेंढकों जैसी प्रतीत हो सकती है जब कोई व्यक्ति सोने का प्रयत्न कर रहा हो, उसी तरह एक छोटी-सी चीज़ को मानसिक डर तथा विकृत कल्पना के द्वारा उसके वास्तविक आकार से कहीं अधिक बड़ा अनुपात प्रदान किया जा सकता है।

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एक बार नार्थ वुड्स (नामक घने जंगल) के काफी भीतर की तरफ़ एक अंधेरी रात के समय एक एकांत केबिन में बैठे हुए मैंने बरामदे से आती हुई कुछ आवाजें सुनीं जिनसे मेरी रीढ़ की हड्डी में एक कंपकंपी दौड़ गई। ये आवाजें कई घुसपैठियों द्वारा सावधानी पूर्वक पास आने के जैसी लग रही थीं। मैं जड़ हो कर अपनी कुर्सी से जकड़ा हुआ बैठा रहा, मेरा एक-एक रोम खड़ा हुआ प्रतीत हो रहा था। उस क्षेत्र में हाल ही में हुई एक हत्या के विषय में समाचार-पत्रों द्वारा किए गए वर्णन मेरेमन में अचानक आने लगे। मैंने सोचा कि मेरा अंत आ गया था किन्तु मैं मरने के लिए बिल्कुल तैयार नहीं था। मैं मरना नहीं चाहता था; मैं वहां से बच निकलना चाहता था। अंत में उस दुविधा को और अधिक सहने में असमर्थ हो कर, और हताशा वाली वीरता से भर कर मैं दरवाज़े की तरफ झपटा और इसे एक झटके के साथ खोल दिया, यह आशा करते हुए कि वहां डाकुओं की एक पूरी सेना मशीन-गनें और पिस्तौलें लिए हुए होगी। इसकी बजाए वहां एक छोटी-सी गिलहरी दौड़ कर अन्धेरे की तरफ़ भाग गई और मैं वहां निष्क्रिय और लज्जित-सा हुआ खड़ा रह गया, किन्तु फिर भी मैंने एक महान् शिक्षा ग्रहण कर ली कि अपने भयों पर एक भरपूर नज़र डाल लेना बहुत हितकारी होता है, तथा यह कि जब आप ऐसा कर लेते हैं तो वे (भय) उतने डरावनेनहीं रहते जितनी आप ने उनके बारे में कल्पना कर ली थी।

ईश्वर में आस्था.

एक महान् जापानी (उपदेशक तथा समाज-सेवक) कगावा एक बार हमारे देश में आया। प्रत्येक व्यक्ति का ध्यान इस ओर गया कि उसमें शान्ति तथा मानसिक सन्तुलन की भावना, एक आंतरिक शक्ति और आत्म विश्वास था जो सचमुच ही असाधारण था। कगावा ने एक अमूल्य रहस्य का भेद पा लिया था, तथा उसने हमें अपना रहस्य यह कहते हुए बताया कि यदि कोई व्यक्ति वैसा ही करेगा जैसा कि वह स्वयं करता है, “एक लंबे समय तक स्वयं को ईश्वर-कृपा में डुबो ले’, तो वह ऐसी गहरी शांति प्राप्त कर लेगा जिसे कोई भी चीज़ नष्ट नहीं कर सकेगी। कगावा ने कहा कि लोगों की भारी भीड़ का सामना करने, सैनिकों द्वारा धमकाए जाने,विरोधियों द्वारा चोट पहुंचाए जाने के बावजूद भी शान्ति ने उसका साथ कभी नहीं छोड़ा था। उसकी आंखों की रोशनी खतरे में पड़ गई थी, रोग उसे कष्ट दे रहे थे; किन्तु उसने शांति का दामन कभी नहीं छोड़ा। उसने विश्वासपूर्ण ढंग से कहा कि अक्सर इस शान्ति की गहराई से वह चकित रह जाता था। उसने हमें यह विश्वास दिलाया कि यह शान्ति उसे ईश्वर से प्राप्त हुई थी। इस संबंध के कारण उसने सब भयों से मुक्ति पा ली थी।

(Page 35)

भय से छुटकारा पाने का वहां एक वास्तविक तरीका है। इस तथ्य में आप एक गहरी और अटल आस्था रखिए कि आप अकेले नहीं हैं, अपितु ईश्वर आप पर पूरी निगरानी रखता है और आप का पूरा ध्यान रखता है और वह आप को सभी कठिनाइयों से बाहर ले आएगा। तब आप को पूर्ण मानसिक शान्ति प्राप्त हो जाएगी।

Punjab State Board PSEB 10th Class Science Important Questions Chapter 5 Periodic Classification of Elements Important Questions and Answers.

PSEB 10th Class Science Important Questions Chapter 5 Periodic Classification of Elements

Long Answer Type Questions

Question 1.
What do you understand by Dobereiner’s triads? Give some examples to support it.
Answer:
In 1817, a German Chemist, Dobereiner, gave a classification in which the similar elements were arranged in groups of three called Triads. The arrangement was such that the atomic mass of the middle element was almost the average of the atomic masses of the first and third elements. For example, if A, B and C are the elements present in the triad, then

Atomic mass of B =\(\frac{\text { Atomic mass of } \mathrm{A}+\text { Atomic mass of } \mathrm{C}}{2}\)

Examples of triads.
A few examples of triads are listed as given ahead :
1. Lithium, Sodium. Potassium
Atomic mass of Lithium (Li) = 7
Atomic mass of Potassium (K) = 39
Atomic mass of Sodium (Na) = \(\frac{39+7}{2}\) = 23
Actual atomic mass of sodium = 23

This group of triads is called Alkali Metal Group. All the elements present are metals, have valency equal to one (1) and dissolve in water to form soluble hydroxides called alkalis.

2. Calcium, Strontium, Barium
Atomic mass of Calcium (Ca) = 40
Atomic mass of Barium (Ba) = 137
Atomic mass of Strontium (Sr) = \(\frac{137+40}{2}=\frac{177}{2}\) = 88.5
Actual atomic mass of strontium = 88

This group of triads is called Alkaline Earth Metals Group. All the elements present are metals, have valency equal to two (2) and their oxides dissolve in water to form hydroxides which are alkaline in nature.

Question 2.
(a) What was Dobereiner’s basis of classifying elements?
Answer:
Dobereiner gave a classification in which the elements were arranged in a group of three elements called triads. The arrangement was such that the atomic masses of the middle elements were almost the average of the atomic masses of the first and third elements.

(b) What is the basis of classification of elements according to Mendeleev?
Answer:
The major contribution in the classification of the elements is by Mendeleev, a Russian chemist. He studied in detail the properties of the elements and made a very important observation. He stated that when elements are arranged in order of increasing atomic masses, the elements with similar properties recur after a definite gap. He based his classification of law called Mendeleev’s Periodic Law. The law may be stated as:

Physical and chemical properties of the elements are periodic function of their atomic weights or atomic masses.

Question 3.
Give a brief discussion of the Mendeleev’s classification of the elements.
Answer:
Mendeleev’s classification of the elements is based upon the Mendeleev’s periodic law. The law helped him to develop a table called Mendeleev’s Periodic Table. The table has been divided into vertical columns which are called Groups and horizontal rows which are known as Periods.

These are briefly discussed as follows :
1. Groups: These are the vertical rows. There are in all eight groups. The elements present in first seven groups are called Normal Elements. The elements present in group VIII are called the Transition Elements. Each group (I to VII) has been further divided into sub-groups which are called A and B. The inert gas or noble gas elements (He, Ne, Ar, Kr, Xe) were not known at that time. Therefore, they were not shown in the table. All the elements placed in a group have the same valency. Ail the elements present in a sub-group have the similar properties. For example, group I-B includes element Cu (Copper), Ag (Silver) and Au (Gold). They have similar properties.

2. Periods: In the periodic table horizontal rows are called periods. There were in all six periods in the original periodic table. The seventh period was added later on and this is not shown in the periodic table. The properties of the elements present in a period change systematically. For example, in every period, the first element is a typical metal. As we move from left to right, the metallic character gradually decreases and non- metallic character increases. For example, in period 2, the first element Li (Lithium) is a metal while the last element F (Fluorine) is a non-metal. The Mendeleev’s Periodic Table is shown below :

Mendeleev’S Periodic Table

Question 4.
(a) Why do we classify elements?
Answer:
To simplify and systematize the study of known elements.

(b) What were the two criteria used by Mendeleev in creating his Periodic Table?
Answer:

1. Mendeleev arranged the elements in order of increasing atomic masses.
2. Mendeleev considered the compounds formed by the elements oxygen and hydrogen.

(c) Why did Mendeleev leave some gaps in his Periodic Table?
Answer:
For the discovery of new elements.

(d) In Mendeleev’s Periodic Table, why was there no mention of Noble gases like7 Helium, Neon and Argon?
Answer:
Because noble gases were not known at that time.

(e) Would you place the two isotopes of chlorine, Cl-35 and Cl-37 in different slots because of their different atomic masses or in the same slot because their chemical properties are the same? Justify your answer.
Answer:
In the same slot because Cl-35 and Cl-37 have same chemical properties.

Question 5.
How did Mendeleev’s Periodic Table help in the discovery of new elements?
Answer:
When Mendeleev gave the periodic table, only 63 elements were known. The classification was based on two major properties :

• Elements are arranged in order of increasing atomic masses.
• Elements present in a group have similar properties.

Many elements were not known at the time the periodic table was given. Therefore, Mendeleev left gaps for these elements in the periodic table. But the properties of these elements could be predicted. For example, let us suppose that Rb (Rubidium) a member of group IA was not known when Mendeleev framed the periodic table. But its properties could be predicted. It was expected to be a metal with valency equal to 1. It was expected to be soluble in water to form a soluble hydroxide RbOH which is an alkali. This helped in the discovery of the element. In this manner, a number of elements could be discovered.

Question 6.
Discuss some major merits of the Mendeleev’s Periodic Table.
Answer:
Merits of Mendeleev’s Periodic Table
Mendeleev’s periodic table was the first proper systematic classification of the elements. The important merits of the table are listed as follows :
1. Systematic study of elements. With the classification of elements into groups and periods, their study became quite systematic. For example, if the properties of one particular element in a group are known, those of the other elements could be predicted. Actually, elements placed in a group are expected to show similar characteristics.

2. Correction of wrong atomic masses. The periodic table helped in correcting the atomic masses of some of the elements because the elements were arranged in order of their increasing atomic masses.

3. Prediction of new elements. At the time Mendeleev gave the periodic table, only 63 elements were known. While arranging these elements in groups and periods, certain gaps were left. These gaps represented some undiscovered elements. But the properties of these unknown elements could be predicted from their positions in the respective groups. This helped, later on, to discover these elements.

Question 7.
On the basis of Mendeleev’s Periodic Table given following, answer the questions that follow the table :

(a) Name the element which is in
(i) 1st group and 3rd period
Answer:
Sodium

(ii) VII group and 2nd period.
Answer:
Fluorine

(b) Suggest the formula for the following :
(i) oxide of nitrogen
Answer:
N₂O₅

(ii) hydride of oxygen.
Answer:
H₂O.

(c) In group VIII of the Periodic Table, why does cobalt with atomic mass 58.93 appear before nickel having atomic mass 58.71?
Answer:
Because the elements with similar properties could be grouped together.

(d) Besides gallium, which two other elements have since been discovered for which Mendeleev had left gaps in his Periodic Table?
Answer:
Scandium and Germanium.

(e) Using atomic masses of Li, Na and K, find the average atomic mass of Li and K and compare it with the atomic mass of Na. State the conclusion drawn from this activity.
Answer:
Average atomic mass of Li and K = \(\frac{6.939+39.102}{2}=\frac{46.04}{2}\) = 23.02
Atomic mass of Na = 22.99
Hence Atomic mass of Na = Average of atomic masses of Li and K = \(\frac{46.04}{2}\) = 23.02

Question 8.
Point out the major defects in Mendeleev’s Periodic Table.
Answer:
Defects in Mendeleev’s Periodic Table:
Mendeleev’s periodic table was quite helpful in the classification of the elements.

But it had certain defects also. These are discussed as follows :
1. Position of hydrogen. Hydrogen was placed at the top of group LA. It is a non-metal where all other elements included in the group are metals.

2. Position of isotopes. The periodic table is based on the basis of the atomic masses of the elements and the elements with different atomic masses must be given separate places in the table. If this is correct, all the isotopes of an element must be allotted separate positions. For example, there are three isotopes for hydrogen and they must be given three separate places in the table. But only one position for hydrogen has been given.

3. Wrong order of atomic masses of some elements. In the table, the elements are arranged in order of increasing atomic masses. This means that the element with higher atomic mass must be placed after the element with the lower atomic mass. But in the table, there are some anomalies. For example, Co (Cobalt) with atomic mass 58-9 should be placed after Ni (Nickel) with atomic mass 58-7. But it has been placed before nickel.

4. Elements with similar properties placed in different groups. In the periodic table, it has been found that the elements with similar properties are placed in different groups. For example, copper and mercury have many common properties. But copper has been placed in group I B and mercury in group II B.

5. No similarity in the elements placed in sub-groups. The elements present in different sub-groups of the same group are expected to have common properties. But these are quite different. For example, elements in group I A are very soft and reactive metals but elements in group IB are hard and less reactive in nature.

6. No explanation for the cause of periodicity. Mendeleev was not in a position to explain why the elements included in a group show similar properties.

Question 9.
Give a brief description of Long Form of Periodic Table.
Answer:
The Long form of periodic table has been formed by arranging the elements in order of increasing atomic numbers. It is based upon Modern periodic law which states that the properties of the elements are the periodic function of their atomic numbers. Just as in case of the Mendeleev’s table, this periodic table has also been divided into Periods and Groups.
(A) Groups
These are the vertical columns. In all, there are eighteen groups in the table. The details of the groups are as follows :

Long Form of Periodic Table of Modern Periodic Table

• Group 1: The elements present in group I or 1 are called Alkali Metals.
• Group 2: The elements which are present in group IIA or 2 are called Alkaline Earth Metals.
• Groups 13 to Group 18: There are in all six groups. The Groups 13 to 16 are named after the first element present in the family. For example, Group IIIA or 13 is called Boron Family because first member is boron.
• Group 17 consists of a family called Halogen Family.
• The group 18 is also called zero group because the elements have zero valency. These elements are ail gases. They have very little tendency to take part in chemical combination. These are also called Noble Gases.

In the latest Long Form of Periodic Table, groups of Alkali metals and Alkaline erttH metals are given numbers 1 and 2. The transition of elements are numbered from its,2 The non-metals are included in groups 13 to 18.

Group No.	Name of Family
Group 13	Boron Family
Group 14	Carbon Family
Group 15	Nitrogen Family
Group 16	Oxygen Family
Group 17	Halogens
Group 18 or zero group	Noble Gases

• Group 3 to Group 12: There are in all ten groups. These are all metals and are called Transition elements. When we go down each group, the metallic character further increases.
• Group 3: Group 3 also includes fourteen elements belonging to Lanthanide family. These are called Lanthanides because they start after Lanthanum (La) with Z = 57. These are present in the 6th period as shown in the table.
• It also includes another fourteen elements called Actinides. These are present in 7th period. These are so called as they come after Actinium (Ac) with Z = 89. These are placed at the bottom of the table for convenience.

(B) Periods
Periods are the horizontal rows which are present in the Long Form of Periodic Table. Different periods have different number of elements and their atomic numbers are continuous. There are in all seven periods. The seventh period is still incomplete. The number of elements which are included in each period are given below :

Period	No. of elements	Name of the Period
1	2	Shortest Period
2	8	Short Period
3	8	Short Period
4	18	Long Period
5	18	Long Period
6	32	Longest Period
7	20	Incomplete Period

Question 10.
What is periodicity? What is the cause of periodicity?
Answer:
Periodicity may be defined as the repetition of the similar properties of the elements placed in a group and separated by definite gaps of atomic numbers (8, 8, 18, 18, 32).

Cause of Periodicity. The properties of the elements, particularly the chemical properties, are linked with number of electrons present in the outermost shell of their atoms which is also called Valence shell. Elements with similar valence shell electronic configurations are expected to have similar properties.

It may be noted that all the elements which are present in a group have the same number of electrons in the valence shells of their atoms. In other words, the same valence shell electronic arrangement gets repeated after definite gaps of atomic numbers (8, 8, 18, 18, 32). Therefore, the elements placed in a group show similar properties.

Example, Let us write the electronic distribution of the first four members of the alkali metals present in group I.

All the four elements have one electron each in the valence shell of their atoms. They have, therefore, similar properties.

Question 11.
(a) What were the two major shortcomings of Mendeleev’s periodic table? How have these been removed in the modern periodic table?
Answer:
The shortcomings of Mendeleev’s periodic table are :

• Isotopes of an element find different positions in periodic table.
• Some chemically similar elements have been separated and some dissimilar elements are placed together.

In these Modern Periodic Table
Modern Table

• Isotopes of an element occupy the same position because they have same atomic number.
• The similar elements are grouped together and dissimilar elements are separated.

(b) Two elements X and Y have atomic numbers 12 and 16 respectively. Write the electronic configuration for these elements. To which period of the modern periodic table do these two elements belong? What type of bond will be formed between them and why?
Answer:

Element	Electronic Configuration	Period
X12	2, 8, 2	3rd
Y16	2, 8, 6	3rd

They will form ionic bonds because two electrons are transferred from X to Y so that they get their octets complete :

Question 12.
Why is Long Form of Periodic Table regarded better than Mendeleev’s Periodic Table?
Or
How could Modern Periodic Table remove various anomalies of Mendeleev’s Periodic Table?
Answer:
Long Form of Periodic Table is regarded better than the Mendeleev’s periodic table due to the following reasons:

• It is based upon atomic number which is considered better than the atomic mass because the properties of the elements are related to the atomic number.
• It explains why the elements placed in a group show similar properties but Mendeleev’s Periodic Table gives no explanation for the same.
• All groups in the Periodic Table are independent groups and there are no sub¬groups as in Mendeleev’s Periodic Table.
• Many defects in the Mendeleev’s Periodic Table have been removed.
• There is no confusion regarding the position of isotopes because all the isotopes of an element have the same atomic number.
• The periodic table is more systematic than the Mendeleev’s table and is easy to remember.

Question 13.
The following tables shows the position of six elements A, B, C, D, E and F in the periodic table.

Using the above table answer the following questions :
(a) Which element will form only covalent compounds?
Answer:
E

(b) Which element is a metal with valency 2?
Answer:
D

(c) Which element is non-metal with valency of 3?
Answer:
B

(d) Out of D and E, which one has a bigger atomic radius and why?
Answer:
D

(e) Write a common name for the family of elements C and F,
Answer:
The noble gases.

Question 14.
The question refers to the elements of the periodic table with atomic number from 3 to 18.

(a) Which of these :
(i) is/are noble gas?
Answer:
H, P

(ii) is it a halogen?
Answer:
G, O

(iii) is an alkali metal?
Answer:
A, I

(iv) is it a metal with valency 2?
Answer:
A, I

(b) Write the electronic arrangement of G.
Answer:
G has the electronic configuration = 2, 7

(c) If A combines with F, what would be the formula of resulting compound?
Answer:

Short Answer Type Questions

Question 1.
Atomic number is considered to be a more appropriate parameter than atomic mass classification of elements in a periodic table. Why?
How does atomic size of elements vary on moving from
(i) Left to right in a period.
(ii) from top to bottom in a group.
Give reasons for your answers.
Answer:

• This is because atomic number is a more fundamental property of an atom.
• As we move from left to right along a period atomic radius decreases due to increase in effective nuclear charge.
• As we move from top to bottom in a group, atomic radius increases. This is due to addition of new electronic shells.

Question 2.
Define periodic law. Why was it necessary to change the basis of classification from atomic masses to atomic numbers?
Answer:
Periodic Law: The properties of elements are a periodic function of their atomic numbers. It was necessary to change the basis of classification from atomic masses to atomic numbers because atomic number and not atomic mass is the fundamental property of an element.

Question 3.
What do you understand by the term periodicity? Do the properties of two elements placed in a group the same? Illustrate.
Answer:
The repetition of the similar properties of the elements placed in a group and separated by definite gaps of atomic numbers (8, 8, 18, 18, 32) is called periodicity. The elements placed in a group show similar properties, e.g. consider group 1 elements.

Element	Symbol	Electronic configuration
Lithium	(3)	Li – 2, 1
Sodium	(11)	Na – 2, 8, 1
Potassium	(19)	K – 2, 8, 8, 1
Rubidium	(37)	Rb – 2, 8, 18, 8, 1
Cesium	(55)	Cs – 2, 8, 18, 18, 1
Francium	(87)	Fr – 2, 8, 18, 32, 18, 8, 1

These elements show similar properties because they have similar outer electronic configurations.

Question 4.
What was wrong with Dobereiner’s classification of elements?
Answer:
Dobereiner classified the elements in group of three in such a way that the atomic mass of the middle element was the mean of the first and the third elements. But he could not find many triads of elements. Therefore, the classification was rejected.

Question 5.
What properties do ail elements in the same column of the periodic table as boron have in common?
Answer:
The elements of Boron family in the periodic table show

• Tricovalency
• Form trihalides
• Form trioxides
• React with halogens to form halides.

Question 6.
Indicate the atomic number of elements of period 3 of Modern periodic table :
(a) non-metals
Answer:
14, 15, 16, 17

(b) elements forming negative ions.
Answer:
15, 16, 17

(c) elements with high melting points.
Answer:
11, 12, 13, 14

(d) elements forming positive ions.
Mention the atomic number only.
Answer:
11, 12, 13

Question 7.
Define atomic radius. Give its units.
Answer:
Atomic radius. It may be defined as the distance between the centre of nucleus and the outermost shell of an isolated atom.

Also the atomic radius of a non-metallic element is defined as half the distance between the nuclei of two atoms bound by a single covalent bond.
Units = Å or pm (picometre)
e.g. atomic radius of hydrogen atom = 37 pm.

Question 8.
How does atomic radius vary down a group and along a period?
Answer:
Variation in a group. The atomic radius generally increases from top to bottom in a group due to the addition of a new shell.
Variation along a period. The atomic radius decreases on moving from left to right due to the increase in nuclear charge.

Question 9.
Write down the electronic configuration of elements with atomic numbers 2, 14, 17, 19. Indicate the group of the periodic table to which they belong.
Answer:
The information is being given in a tabular form.

Atomic number	Electronic configuration K L M N	Group
2	2	18
14	2, 8, 4	14
17	2, 8, 7	17
19	2, 8, 8, 1	1

Question 10.
Locate the following group in the periodic table :
(a) Alkali metals
Answer:
Alkali metals: Group 1 or IA

(b) Halogens
Answer:
Halogens: Group 17 or VIIA

(c) Alkaline earth metals
Answer:
Alkaline earth metals: Group 2 or IIA

(d) Noble gases.
Answer:
Noble gases: Group 18 or zero

Question 11.
What properties do the elements in the same vertical column of the periodic table as fluorine have in common?
Answer:
These are :

• They form diatomic molecules F₂, Cl₂, Br₂ I₂
• They are non-metals.
• They show a valency of one.

Question 12.
Write the chemical electronic configuration of nitrogen (N = 7) and phosphorous (P = 15).
Answer:

Question 13.
(i) Name the members of the alkaline earth family.
Answer:
The members of the alkaline earth family are :
Be, Mg, Ca, Sr, Ba, Ra.

(ii) To which group do they belong?
Answer:
They belong to group 2.

(iii) Which member is radioactive in nature?
Answer:
The radioactive member in them is Radium (Ra).

(iv) Which member is the least reactive?
Answer:
The least reactive member of the family is Beryllium (Be).

Question 14.
Why are the members of group 1 called alkali metals?
Answer:
The members of group 1 are called alkali metals because all of them are water soluble. They react with water to form soluble hydroxides. The soluble hydroxides of the metals are called alkalies.

Question 15.
An atom has the electronic configuration 2, 8, 7.
(a) What is the atomic number of this element?
Answer:
The atomic number of the element = Total number of electrons
= 2 + 8 + 7 = 17

(b) To which of the following elements would it be chemically similar? (atomic numbers are given) N (7), F (9), P (15), Ar (18).
Answer:
The electronic configurations of given atom and N, F, P and Ar are.

Atom	Electronic configuration
	K	L	M
	2	8	7
N	2	5
F	2	7
P	2	8	5
Ar	2	8	8

Since F has same number of electrons in the outermost shell as the given atom. Hence, the given atom is chemically similar to F.

Question 16.
What physical and chemical properties of elements were used by Mendeleev in creating his periodic table? List two observations which posed a challenge to Mendeleev’s Periodic Law.
Answer:
He selected the compounds of the elements with oxygen and hydrogen. He gave a table based upon atomic weights of the elements.

Limitations of Mendeleev’s Classification

• The position of hydrogen was uncertain.
• The isotopes of elements were not given proper positions in the periodic table.

Question 17.
(a) What are amphoteric oxides? Choose the amphoteric oxides from amongst the following oxides :
Na₂O, ZnO, Al₂O₃, CO₂, HaO
Answer:
The oxides which can react both with acids as well as bases to produce salts and water.

(b) Why is it that non-metals do not displace hydrogen from dilute acids?
Answer:
This is because non-metals cannot lose electrons and cannot reduce H⁺ ions from acid to H₂.

Question 18.
What are noble gas elements? Why are they so called?
Answer:
Noble gas elements are the. elemehts present in group 18 of the periodic table which is also called zero group, It means that the valency of the elements is zero. Actually, whereas the first member helium has two electrons in its only shell, the atoms of the remaining elements (Neon, Argon, Krypton, Xenon and Radon) have eight electrons in their outermost shells. They do not have any tendency to combine with atoms of other elements. Hence, they show zero valency. These are also called noble gases because they do not take part in chemical combination.

Question 19.
How is metallic character of an element defined? How does the metallic character of the elements change in a group?
Answer:
The metallic character of an element may be expressed in terms of its tendency to lose electrons and to form positive ion.
M (Element) → M⁺ + e^–

In a group the metallic character increases’ downwards. For example, among the elements of group 2, Beryllium (Be) is the least metallic. At the same time, radium (Ra) which is the last element is maximum metallic in nature.

Question 20.
Why do the elements present in a group show similar chemical properties?
Answer:
The properties of the elements, particularly the chemical properties are related to valence shell electronic distribution. The elements with the same valence shell electronic distribution have the similar chemical properties. For example, the members, of alkaline earth metal family (Group 2) have two electrons in the valence shell of their atoms. They therefore, show similar chemical properties.

Question 21.
How does the reactivity of the metals vary in a group?
Answer:
In a group, containing metals, the reactivity increases down the group. For example, in the metals of group 1 (Alkali metals), Lithium reacts with water very slowly. Sodium is more reactive and potassium is. still more reactive than sodium.

Question 22.
Name the elements present in the second period. Give their electronic configuration.
Answer:
The second period of the Long Form of Periodic Table has eight elements. The first element is Lithium and the last element is Neon. The electronic configuration of the elements are given below:

Question 23.
Why do not the elements present in a period show same valency?
Answer:
The valency of the element is related to the number of electrons in the outermost energy shell of its atom. Since the elements present in a period have different number of valence electrons or outermost electrons, they show different valencies.

Question 24.
The metallic character of the elements in a period decreases from left to the right. Justify.
Answer:
In every period, as we move from left to right, the metallic character of the elements decreases gradually. This is shown with the elements present in the third period.

Question 25.
Give symbols for :
(a) a metal belonging to second group of the periodic table.
Answer:
The metal belonging to second group is calcium (Ca).

(b) a metal belonging to the third group of the periodic table.
Answer:
The metal belonging to third group is aluminium (Al).

(c) two non-metals belonging to the halogen family.
Answer:
The two non-metals of halogen family are fluorine (F) and chlorine (Cl).

Question 26.
Write electronic structures of:
(i) Potassium
(ii) Lithium
(iii) Fluorine.
Answer:
The electronic configurations of the atoms are given below :

Question 27.
Name two other elements which are in the same family as
(i) carbon
Answer:
Carbon belongs to the group 16. Two other elements are silicon (Si) and germanium (Ge).

(ii) fluorine
Answer:
Fluorine belongs to group 17. Two other elements are chlorine (Cl) and bromine (Br).

(iii) sodium.
Answer:
Sodium belongs to group 1. Two other elements are lithium (Li) and potassium (K).

Question 28.
Carbon (atomic number 6) and silicon (atomic number 14) are elements in the same group of the periodic table. Give the electronic arrangements of the carbon and silicon atoms and state the groups in which these elements occur.
Answer:
The required information may be given in a tabular form as follows :

Element	Atomic no.	Electronic arrangement	Group
Carbon (C)	6	2, 4	14
Silicon (Si)	14	2, 8, 4	14

Question 29.
Sodium and aluminium have atomic numbers of 11 and 13 respectively. They are separated by one element in the periodic table and have valencies of 1 and 3 respectively. Chlorine and potassium are also separated by one element in the periodic table (their atomic numbers are 17 and 19 respectively) and yet both have valency of one. Explain your answer.
Answer:
Sodium and aluminium: The electronic configurations of the elements are given below :
Sodium (Na) = 2, 8, 1
Aluminium (Al) = 2, 8, 3

The valency in this case is given by the number of valence electrons. Therefore, the valency of sodium is 1 and that of aluminium is 3.

Chlorine and potassium: The electronic configurations of the elements are given below :
Chlorine (Cl) = 2, 8, 7
Potassium (K) = 2, 8, 1

Question 30.
Give the atomic number and electronic distribution of:
(i) The third alkali metal
Answer:
Potassium (19) 2, 8, 8, 1

(ii) The second alkaline earth metal
Answer:
Magnesium (12) 2, 8, 2

(iii) The first halogen
Answer:
Fluorine (9) 2, 7

(iv) The second noble gas.
Answer:
Neon (10) 2, 8.

Question 31.
Observe the following elements in the Modern Periodic Table.

Name the elements A, B, C and D. Also indicate noble gas
Answer:
(A) Lithium
(B) Chlorine
(C) Neon
(D) Potassium C is a noble gas

Question 32.
Match the following :

(a) Fluorine	(i) Metalloid
(b) Neon	(ii) Halogen
(c) Sodium	(iii) Noble gas
(d) Arsenic	(iv) Alkali metal

Answer:

(a) Fluorine	(ii) Halogen
(b) Neon	(iii) Noble gas
(c) Sodium	(iv) Alkali metal
(d) Arsenic	(i) Metalloid

Question 33.
How many electrons can be present in the valence shells of metal atoms and non-metal atoms?
Answer:
Metal atoms have 1, 2 or 3 electrons in their valence shells whereas non-metal atoms have 4 to 7 electrons in their valence shells.

Question 34.
How are the various groups of the Modern Periodic Table designated according to the IUPAC system and old system?
Answer:
The designations of various groups of the Modern periodic table are :

Question 35.
What are the uses of Modern Periodic Table?
Answer:

• Systematic study of the elements. In the periodic table, the elements with similar properties are placed together in the same group. If we know the properties of one element of the group, the properties of other elements belonging to the same group can be predicted. Thus, there is no need to study the properties of all the elements.
• Properties of an element can be predicted from the position of the element in the periodic table. For example, if the element belongs to group IA or IIA it is likely to be a reactive metal, and if it belongs to group VII A it is likely to be a reactive non-metal.
• It has led to the discovery of many new elements.

Very Short Answer Type Questions

Question 1.
How many elements have been discovered so far?
Answer:
114.

Question 2.
How are elements classified?
Answer:
The elements have been classified on the basis of their properties.

Question 3.
Why are group IA elements called alkali metals?
Answer:
This is because all these elements are metals and their oxides and hydroxides give alkaline solutions in water.

Question 4.
What is the basis of Modern Periodic table?
Answer:
It is based upon Modern Periodic law.

Question 5.
Name the family to which halogens belongs?
Answer:
Halogen family.

Question 6.
Name the second elements of group 14.
Answer:
Silicon.

Question 7.
How many valence electrons and present in halogen elements?
Answer:
Seven.

Question 8.
How many elements are present in 4th period?
Answer:
18.

Question 9.
How many electrons are present in Mg²⁺ ion?
Answer:
Ten.

Question 10.
Out of Na and Mg which was larger size?
Answer:
Na

Question 11.
What is the valency of nitrogen?
Answer:
Three.

Question 12.
Out of Na and K which is more reactive?
Answer:
Sodium (Na).

Question 13.
Name the group number of halogen family.
Answer:
Group 17 (or VII-A).

Question 14.
Name the last element of third period?
Answer:
Argon.

Question 15.
What is Dobereiner’s Triad?
Answer:
A group of three elements having similar properties is called Dobereiner’s Triad.

Question 16.
A, B and constitute the Dobereiner s Traid. Atomic mass of A and C are 7 and 23 respectively. Calculate atomic mass of B.
Answer:
\(\frac{7+23}{2}=\frac{30}{2}\) = 15

Question 17.
Name the elements discovered after Mendeleev’s Periodic Table?
Answer:
Scandium (Se), Gallium (Ga), Germanium (Ge) etc.

Question 18.
Name the groups and periods in Mendeleev’s Periodic Table?
Answer:
8 groups and 7 periods.

Question 19.
How does atomic radii as we move from left along a period in the Periodic Table?
Answer:
It decreases.

Question 20.
An element has the electronic configuration 2, 8, 3. What is its group number in Modern Periodic Table?
Answer:
Group 13.

Question 21.
Give the basis of Dobereiner’s classification.
Answer:
Doberenier Triads.

Question 22.
Give the characteristics of Dobereiner’s Triads.
Answer:
The atomic mass of the central element is the average of masses of the other two elements.

Question 23.
What is the drawback of Doberenier’s Triads?
Answer:
All the known elements could be grouped into Triads.

Question 24.
There are three alements A, B and C. The atomic masses of A and C are 7 and 39. What is the atomic mass of B on the bais of Dobereiner’s Traids?
Answer:
Atomic mass of B = \(\frac{7+39}{2}\) = 23.

Question 25.
There are three elements X, Y, Z. Atomic masses of X and Z are 35.5 and 127. What will be atomic mass of Y on the basis of Dobereiner’s Traids?
Answer:
Atomic mass of Y
\(\frac{35.5+127}{2}=\frac{162.5}{2}\) = 81.25

Question 26.
Write Newland’s Law of Octaves for classification of elements.
Answer:
When the elements are arranged in order of increasing atomic masses, eighth elements has properties similar to the first element.

Question 27.
How many element were classified by Newland.
Answer:
Upto mass number 40.

Question 28.
Indicate the group number and period number of P in the modern Periodic Table.
Answer:
Group-15, Period-3.

Question 29.
An element has the electronic configuration 2, 8, 8, 2. Indicate its group and Period in the Modern Periodic Table.
Answer:
Group-12, Period-4.

Question 30.
An element M is in the group 13 of Modern Periodic Table write the formula of its oxide.
Answer:
M₂O₃.

Question 31.
Give the groups and periods in the Modern Periodic Table.
Answer:
Group-18, Periods-7.

Question 32.
Give the electronic configuration of ₁₇Cl³⁵. Also indicate its position in the Periodic Table.
Answer:
Electronic configuation of ₁₇Cl³⁵ = 2, 8, 7
Period number = 3
Group number =17. (VII A)

Question 33.
Give the name and electronic configuation of element with atomic number 9.
Answer:
Fluorine and it has the electronic configuation = 2, 7.

Question 34.
What is Modern Periodic Law?
Answer:
It states that the properties of the elements are the periodic functions of their atomic numbers.

Question 35.
Who gave Newland’s Law of Octaves.
Answer:
Newland.

Question 36.
Define Mendeleev’s periodic law.
Answer:
It states that the properties of the elements are the periodic functions of their atomic masses.

Question 37.
What is the basis of Mendeleev’s Modern Table?
Answer:
It is based upon Mendeleev periodic law and in this table the elements are arranged in order of increasing atomic masses.

Question 38.
How many groups are present in Mendeleev’s Period Table.
Answer:
Eight.

Question 39.
Name the next elements after P in Modern Periodic Table.
Answer:
Sulphur (S).

Question 40.
Give the group number of nitrogen and phosphorus.
Answer:
They belong to group number 15.

Question 41.
Out of Mg and Al which is more metallic?
Answer:
Mg.

Question 42.
Out of Be, Mg, Ca, Al which does not belong to same group?
Answer:
Al.

Question 43.
In which group noble gases are present?
Answer:
Group 18 or group zero.

Question 44.
Na and S are present in the third period of Modern Periodic Table. Which is more metallic and why?
Answer:
Na is more metallic due to larger size than S.

Question 45.
What is metallic character?
Answer:
It is the tendency of an atom of the element to form positive ions by losing electrons.

Question 46.
What is the trend in metallic character on moving from left to right along a period?
Answer:
It decreases.

Multiple Choice Questions:

Question 1.
Who gave Law of octaves?
(A) Newland
(B) Dobereiner
(C) Mendeleef
(D) Lother Mayer.
Answer:
(A) Newland

Question 2.
In Mendeleef’s periodic table which element was discovered in the gap between Boron and Aluminium ?
(A) Na
(B) Ca
(C) Ga
(D) Ba.
Answer:
(C) Ga

Question 3.
According to Mendeleef’s periodic law, the elements are arranged in order of A increasing:
(A) Atomic numbers
(B) Decreasing atomic number
(C) Increasing atomic masses
(D) Decreasing atomic masses.
Answer:
(C) Increasing atomic masses

Question 4.
Which element occupied gap left in Mendeleers periodic table?
(A) Germanium
(B) chlorine
(C) Oxygen
(D) Silicon.
Answer:
(A) Germanium

Question 5.
An element has the electronic configuration 2, 8, 2. It is present in group:
(A) 2
(B) is
(C) 8
(D) 10.
Answer:
(A) 2

Question 6.
Which element shows metallic character?
(A) 2, 8, 2
(B) 2, 8, 4
(C) 2, 8, 8
(D) 2, 7.
Answer:
(A) 2, 8, 2

Question 7.
Which shell is largest shell?
(A) K
(B)L
(C) M
(D) N.
Answer:
(D) N

Fill in the blanks :

Question 1.
Out of Na and Mg, ______ has bigger size.
Answer:
Na.

Question 2.
Number of elements known in Mendeleefs periodic table were ______
Answer:
63.

Question 3.
Oxygen and sulphur belong to same ______
Answer:
group.

Question 4.
The elements of group 17 are called ______
Answer:
halogens.

Question 5.
The valency of the members of noble gas family is ______
Answer:
zero.

Question 6.
The halogens belong to group ______
Answer:
17.

Punjab State Board PSEB 10th Class Science Book Solutions Chapter 5 Periodic Classification of Elements Textbook Exercise Questions and Answers.

PSEB Solutions for Class 10 Science Chapter 5 Periodic Classification of Elements

PSEB 10th Class Science Guide Periodic Classification of Elements Textbook Questions and Answers

Question 1.
Which of the following statements is not a correct statement about the trends when going from left to right across the periods of periodic table.
(а) The elements become less metallic in nature.
(b) The number of valence electrons increases.
(c) The atoms lose their electrons more easily.
(d) The oxides become more acidic.
Answer:
(c) The atoms lose their electrons more easily.

Question 2.
Element X forms a chloride with the formula XCl₂, which is a solid with a high melting point. X would most likely be in the same group of the periodic table as :
(a) Na
(b) Mg
(c) Al
(d) Si
Answer:
(b) Mg

Question 3.
Which element has :
(а) two shells, both of which are completely filled with electrons?
Answer:
Neon

(b) the electronic configuration 2, 8, 2?
Answer:
Magnesium

(c) a total of three shells, with four electrons in its valence shell?
Answer:
Silicon

(d) a total of two shells, with three electrons in its valence shell?
Answer:
Boron

(e) twice as many electrons in its second shell as in its first shell?
Answer:
Carbon.

Question 4.
(a) What property do all elements in the same column of the periodic table as Boron have in common?
Answer:
All elements of this column have 3 electrons in their valence shell like Boron.

(b) What property do all elements in the same column of the periodic table as Fluorine have in common?
Answer:
All elements of this column have 7 electrons in their valence shell like fluorine.

Question 5.
An atom has electronic configuration 2, 8, 7.
(а) What is the atomic number of this element?
Answer:
17

(b) To which of the following element would it be chemically similar? (atomic numbers are given in parenthesis).
N (7), F (9), P (15), Ar (18).
Answer:
F (9) (2, 7)

Question 6.
The position of three elements A, B and C in the periodic table are as shown below :

(а) State whether A is a metal or non-metal.
Answer:
A is non-metal.

(b) State whether C is more reactive or less reactive than A.
Answer:
C is less reactive than A.

(c) Will C be larger or smaller in size than B.
Answer:
C has smaller size than B.

(d) Which type of ion, cation or anion, will be formed by element A?
Answer:
Anion, A-.

Question 7.
Nitrogen (atomic number 7) and phosphorus (atomic number 15) belong to group 15 of the periodic table. Write the electronic configurations of these two elements. Which of these will be more electronegative? Why?
Answer:

	K	L	M
N7 has electronic configuration	2	5
P15 has electronic configuration	2	8	7

Nitrogen is more electronegative than Phosphorus due to smaller size.

Question 8.
How does the electronic configuration of an atom relate to its position in the Modern Periodic Table?
Answer:
By knowing the electronic configuration of an element, we can know its period number from the number of shells present in its atom and from number of electrons in the valence shell of its atoms we can know its group number, e.g. let us consider the case of sodium atom.

Atomic number of sodium = 11
Its electronic configuration = 2, 8, 1 (K) (L) (M)
∴ Number of shells = 3
∴ Sodium belongs to 3rd period.

Also sodium atom has one electron in its valence shell.
∴ It is present in first group.
∴ Sodium lies in the first group and third period of Modern Periodic Table.

Question 9.
In the Modern Periodic Table, calcium (atomic number 20) is surrounded by elements with atomic numbers 12,19, 21 and 38. Which of these have physical and chemical properties resembling calcium?
Answer:
Element with atomic numbers 12 and 38 because they have two electrons in their valence shells like calcium (2, 8, 8, 2).

Question 10.
Compare and contrast the arrangement of elements in Mendeleev’s Periodic table and the Modern Periodic table.
Answer:
Similarities :

• In both the elements are arranged in groups and periods.
• In both similar elements are placed in same group.
• Both the classification make the study of elements simple and systematic.

Differences :

Mendeleev’s Periodic Table	Modern Periodic Table
1. The elements are arranged in order of increasing mass numbers.	1. The elements are arranged in order of increasing atomic numbers.
2. It has 8 vertical columns called groups.	2. It contains eighteen vertical columns called groups.
3. Groups like group VIII ‘have been divided into sub groups A and B.	3. Each group is an independent group.
4. Inert gases are not included in this table.	4. Inert gases are included in this periodic table.

Science Guide for Class 10 PSEB Periodic Classification of Elements InText Questions and Answers

Question 1.
Did Dobereiner’s triads also exist in the columns of Newlands’ octaves? Compare and find out.
Answer:
Yes, Dobereiner’s triads also existed in columns of Newlands’ octaves. These are:

H	Li	Be
F	Na	Mg
Cl	K	Ca

Question 2.
What were the limitations of Dobereiner’s classification?
Answer:

• Dobereiner could find only three triads from the elements known at that time.
• It is applicable only to a few elements.

Question 3.
What were the limitations of Newlands’ law of octaves?
Answer:

• It is applicable upto calcium only.
• Sometimes two elements were put in the same slot.
• After the discovery of noble gas, law of octave is not valid.

Question 4.
Use Mendeleev’s periodic table to predict the formulae for the oxides of following elements :
K, C, Al, Si, Ba.
Answer:
K₂O, CO₂, Al₂O₃, SiO₂, BaO.

Question 5.
Besides Gallium, which other elements have since been discovered to fill the gaps left by Mendeleev in his periodic table? (any two)
Answer:
Scandium and Germanium.

Question 6.
What were the criteria used by Mendeleev in creating his periodic table?
Answer:

• The formulae of hydrides and oxides formed by an element wrere treated as one of the basic properties of an element for its classification.
• It is based upon Mendeleev’s periodic law which predicts that the properties of the elements are the periodic function of their atomic masses.

Question 7.
Why do you think the noble gases are placed in a separate group?
Answer:
These gases were discovered very late because they are very inert and placing them in a separate group, does not disturb the existing order put forward by Mendeleev.

Question 8.
How could Modern Periodic Table remove various anomalies of Mendeleev Periodic Table?
Answer:

• Isotopes of an elements occupy same position in the periodic table due to same atomic number.
• There is a logical separation of elements into subgroups.
• It is based upon the fundamental property of an element i.e. atomic number.

Question 9.
Name two elements you would expect to show same kind of chemical reactivity as magnesium. What is the basis for your choice?
Answer:
Calcium and Strontium because they have same number of valence electrons.

Question 10.
Name :
(а) three elements that have only a single electron in their outermost shells.
Answer:
Lithium, Sodium and Potassium.

(b) two elements that have two electrons in their outermost shells.
Answer:
Magnesium, Calcium.

(c) three elements with filled outermost shells.
Answer:
Neon, Argon, Krypton.

Question 11.
(a) Lithium, Sodium, Potassium are all metals that react with water to liberate hydrogen gas. Is there any similarity in the atoms of these elements?
Answer:
One electron in their valence shells and are metals.

(b) Helium is an unreactive gas and neon is a gas of extremely low reactivity. What, if anything, do their atoms have in common?
Answer:
Eight electrons in their valence shells.

Question 12.
In the modern periodic table, of the first ten elements, which are metals?
Answer:
Lithium and Beryllium.

Question 13.
By considering their position in the periodic table, which one of the following elements would you expect to have the most metallic characteristics?
Ga Ge As Se Be.
Answer:
Gallium.

Punjab State Board PSEB 10th Class Science Important Questions Chapter 4 Carbon and its Compounds Important Questions and Answers.

PSEB 10th Class Science Important Questions Chapter 4 Carbon and its Compounds

Long Answer Type Questions

Question 1.
What is allotropy? Name the allotropes of carbon. Are they chemically same? Compare their physical properties.
Answer:
Allotropy: The phenomenon of existence of two or more different physical forms of the same chemical element, with same chemical properties is called allotropy.

Allotropes of carbon

• Diamond
• Graphite

Similarity in chemical composition:
If both the allotropes in equal amount are heated in air then both will release same amount of carbon dioxide and will not leave any residue. Therefore this proves that both are same in chemical composition.

Comparison of Physical Properties

Property	Diamond	Graphite
1. Appearance	Transparent	Black, shiny
2. Hardness	Very hard	Soft, slippery/ smooth in touch
3. Heat conductivity	Very less	Medium conductor
4. Electric conductivity	Bad conductor	Good conductor
5. Density (kg/m3)	3 – 510	2 – 250
6. Purity	Purest	Less pure than diamond
7. Melting point	3500°C	3000°C
8. Uses/Applications	Jewellery, drilling purpose Lubricants.	Drycells, Electric Arcs, Pencils, Lead,

Question 2.
What is covalent bond? Write its properties.
Answer:
The chemical bond formed by sharing of electrons between atoms of same or different non-metal elements is known as covalent bond.

Properties of Covalent bond/bonds.

• They hax e strong bonds within molecules but their inter molecular bond is weak.
• They have low boiling points.
• They have low melting points.
• Their compounds are bad conductors of electricity.

Question 3.
(a) Why does carbon form largest number of compounds?
Answer:
This is due to its tetracovalency and catenation.

(b) Why are some of these called saturated and other unsaturated compounds?
Answer:
The compounds containing C – C single bond are called saturated compounds and the compound containing

bonds are called unsaturated compounds.

(c) Which of these two is more reactive?
Answer:
Unsaturated compounds are more reactive than saturated compounds.

(d) Write the names of the compounds
(i) CH₃ – CH₂ – Br
Answer:

Answer:

Question 4.
Write about nomenclature of carbon compounds.
Answer:
The names of compounds in a homologous series are based on the name of basic carbon chain modified by a prefix’ ‘phrase before’ or ‘suffix’ ‘phrase after’ indicating the nature of the functional group. For example, the names of various alcohols are methanol, ethanol, propanol and butanol.

Naming of carbon compound can be done by the following method :

• Identify the number of carbon atoms in the compound. A compound having three carbon atoms will have the name propane.
• In case a functional group is present, it is indicated in the name of the compound with either a ‘prefix’ or a ‘suffix’. Like chloro propane, bromo propane, propanal, propanone etc.
• If the name of functional group is to be given on the basis of suffix, the name of the carbon chain is modified by deleting the final ‘e’ and adding the appropriate suffix. For example, a chain having three carbons with a Ketone group will be given name in the following manner.
  Propane-‘e’ = propan + ‘one’ = propanone.
• If the carbon chain is unsaturated then the final ‘ane’ in the name of carbon chain is substituted by ‘ene’ or ‘yne’. For example, a three-carbon chain with a double bond would be called propene and if it has triple bond, it would be called propyne.

Question 5.
Write down the chemical properties of carbon compounds.
Answer:
The main chemical properties of carbon compounds are :
1. Burning: Carbons in all its allotropic forms burns in the presence of oxygen and produces heat, light and C02, For example :
C + O₂ → CO₂ + heat and light
CH₄ + 2O₂ → CO₂ + 2H₂O + Heat and light
CH₃CH₂OH + 3O₂ → 2CO₂ + 3H₂O + Heat and light.
Saturated hydrocarbons burn with a clear flame whereas unsaturated hydrocarbons burn with sooty yellow flame.

2. Oxidation: Carbon compounds can easily be oxidised by burning. Alkaline potassium permanganate or acidified potassium permanganate converts alcohols into acids.

3. Addition reaction: Unsaturated hydrocarbons make saturated hydrocarbons by adding hydrogen to itself in the presence of catalysts like nickel and palladium. The reaction is commonly used in hydrogenation of vegetable oils using nickel catalyst.

Vegetable oils generally have long unsaturated carbon chain while animal fats have saturated carbon chains.

4. Substitution reaction: Saturated hydrocarbons are fairly unreactive and are inert in the presence of most reagents. However, in the presence of sunlight, chlorine gets combined with hydrocarbons in a quick reaction. Chlorine replaces very quickly the hydrogen atoms in the chemical reaction one by one due to which number of products are usually formed with the higher homologous of alkanes.

Question 6.
(a) What is an alcohol? Give two examples.
Answer:
Alcohol is a simple compound of carbon, hydrogen and oxygen. If one hydrogen atom is replaced by hydroxyl (-OH) group in alkene, alcohol is produced. General formula of alcohol is C_nH_2n+2

Examples :

• In Methane (CH₄) when hydrogen atom is replaced by hydroxyl (- OH) group, methanol (CH₃OH) is formed.
• Ethanol (C₂H₅OH) is produced with the help of ethane

(b) How is synthetic ethanol produced? Also write.
Answer:
Synthetic ethanol is prepared by reacting ethane with water in the presence of phosphoric acid (H3P04).

Properties of Ethanol :

• It is a colourless liquid with specific colour.
• Its boiling point is 351 K and melting point is 156 K.
• It is soluble in water in any proportion.
• It doesn’t show any reaction with litmus because it is neutral.
• It burns with blue flame in air to produce carbon dioxide and water.
  C₂H₅OH + 3O₂ → 2CO₂ + 3H₂O
• It reacts with oxygen or potassium dichromate (K₂Cr₂O₇) to produce ethanoic acid.
  C₂H₅OH + O₂ → CH₃COOH + H₂O
• It reacts with sodium metal.
  2C₂H₅OH + 2Na → 2C₂H₅ONa + H₂
• It reacts with acetic acid in the presence of concentrated H₂SO₄. When this mixture is heated and poured in ice cold solution of sodium carbonate, a sweet smell is produced.

Question 7.
Give important properties of monocarboxylic acids. Also give its uses.
Or
Give important properties of ethanoic acid (Acetic acid). Also give its uses.
Answer:
Important properties of monocarboxylic acid :
1. Ethanoic acid or acetic acid is colourless liquid and is soluble in water, 5-8% solution of acetic acid in water is called vinegar.

2. Pure ethanoic acid melts at 290 K and freezes during winter in cold climates and looks like ice. Hence it is called glacial acetic acid.

3. Esterification: When an acid is heated with an alcohol in the presence of cone. H2S04, an ester is produced. This is a slow reversible reaction and is called esterification.

Esters are sweet-smelling substances.

4. Action with a base

5. Action with carbonates and bicarbonates
Ethanoic acid decomposes carbonates and bicarbonates producing salt, carbon dioxide and water.
2CH₃COOH + Na₂CO₃ → 2CH₃COONa + H₂O + CO₂ ↑
CH₃COOH + NaHCO₃ → CH₃COONa + H₂O + CO₂ ↑

Uses of ethanoic acid :

• It is used in the manufacture of dyes, perfumes and rayon.
• It is used in the manufacture of plastics, rubber and silk industries.
• It is used as a solvent.
• It is used as a vinegar in cooking, as food dressing and for preparing pickles.
• It is used for the manufacture of chemicals like acetone, acetic anhydride, etc.
• It is used for making white lead [2PbCO₃. Pb(OH)₂]

Question 8.
Explain the following terms :
(i) Esterification
Answer:
Alcohols are treated with carboxylic acids in the presence of concentrated sulphuric acid to form ester and this process in known as esterification.

Method: Mix ethyl alcohol with acetic acid in a test tube. Few drops of concentrated sulphuric acid is added and test tube is heated mildly in hot tub of water. Instantaneously sweet smell of ester is diffused in whole room.

It is an example of esterification. Ester is used in ice-cream, cold drinks, medicines, make up etc.

(ii) Saponification
Answer:
Saponification: Breaking down of fats is called saponification.

It is performed by heating vegetable or animal oils with 40% solution of caustic soda. Fats and base react to produce soap and glycerol.

Concentrated common salt solution is added to crystallize soap from water. Soap floats on the surface of water, after cooling. Soap is extracted from water and desired colour and smell are added and is given desired shape.

(iii) Decarboxylation
Answer:
Decarboxylation: Methane is produced when sodium or potassium salt of ethanoic acid are heated with sodium hydroxide and calcium oxide in 3 : 1 ratio.

It is a useful method to prepare methane. It is known as decarboxylation because one molecule of CO₂ is removed.

(iv) Polymerization.
Answer:
Polymerization: When a large number of small molecules join together at a specific temperature and pressure to form a big molecule, this process is termed as polymerization. These small molecules are known as ‘monomer’ whereas big combined molecule is known as ‘polymer.’
For example. Molecules of ethene join together at 2000 atm pressure and 200°C to form polythene.

Question 9.
Describe a method for the preparation of soap.
Answer:
Soaps are sodium or potassium salts of higher fatty acids. When the naturally occurring esters called fats or oils are heated with NaOH solution, they undergo hydrolysis to form sodium salt of higher fatty acid (called soap) and glycerol.

Manufacture of Soap. Soap can be made easily in the laboratory. Heat fat or oil with sodium hydroxide solution. After a few minutes, and constant stirring, the oil and water layers get mixed.

Add 5-10 g of common salt to it, stir the mixture and allow’ it to cool. On cooling, pale yellow a solid forms as a cake called soap.

The same principle is used for making soap in soap industry. Some other substances like perfumes, disinfectants and medicines are added to soap to give it desired characteristics.

Example :

Question 10.
What do you understand by isomers? Explain it with an example.
Or
Write down the isomers of butane.
Answer:
Isomers. The compounds with same molecular formula but different structural formula are called isomers and the phenomenon is called isomerism. There is no change in the structure of methane, ethane, propane if the atoms of carbon and hydrogen are rearranged but in case of alkane molecule if number of carbon is more than three then more than one arrangement is possible.

In this one long carbon chain is formed and the others are branched. In case of butane the chain is linked with atleast three carbon atoms with other carbon atoms. This type of alkanes are termed as iso-alkane. In a chain having no branch, carbon atom cannot be linked with two carbon atoms. Alkanes of this type are called normal alkane (n-alkane).

Two Isomers of Butane:

Isomers of Pentane

Short Answer Type Questions

Question 1.
Explain why carbon forms mostly covalent compounds?
Answer:
Carbon has four electrons in its outermost shell. In order to get stable electronic configuration, it has to lose or gain four electrons, but it is difficult to lose or gain four electrons from energy considerations. Hence, Carbon complete its octet by sharing its valence electrons with other atoms forming covatent bonds resulting in the formation of covalent compounds.

Question 2.
In order to form large amount of carbonic compounds which major elements are used other than hydrogen and oxygen?
Answer:
The number of carbonic compounds is very large which was not possible only with the help of hydrogen and oxygen. Along with these two elements some other elements like nitrogen, sulphur, oxygen, halogens (Cl, Br, I, F) etc. also combine and because of it the caybonic compounds have crossed the number of many million. These combine together on the basis of functional groups and make new compounds.

Question 3.
‘Carbon is a unique element’, why?
Answer:
Carbon is the only known element out of all other known elements, that has got capability to make long chains. Each long chain of carbon atoms provides such a simple base with which other atoms can join by various methods resulting in the composition of various compounds.

Carbon atoms can make long chains or rings in three ways because of having catenation property.

Question 4.
Explain the structure of diamond and write why is it so hard?
Answer:
In diamond each carbon atom remains at the centre of regular tetrahedral and it remains bound with covalent bond to four carbon atoms which are situated at four corners of tetrahedral. Thus, all electrons of carbon are bound atoms and none is found in free state. So it forms a strong three-dimensional tetrahedral structure and because of it diamond is the hardest substance with very high density.

Question 5.
What are the uses of diamond?
Answer:
Uses of Diamond

• Diamond being the hardest substance is used for cutting other substances.
• Diamond because of its shine and lustre is used for making ornaments.
• It is used for drilling hard rocks.
• Sharp-edged diamonds are used by eye surgeon in catract surgery.
• Being extra ordinarly sensitive for heat radiations and having property to remove immediately harmful radiations. These are used in making absolute thermometers.

Question 6.
Why do diamonds glitter?
Answer:
Diamond is a transparent substance whose refractive index is very high. The rays of light passing through it get diverted much. According to its cut base edges light rays undergo total internal reflection. When these edges are polished, diamond glitters very beautifully.

Question 7.
How are diamonds made naturally and artifically?
Answer:
Naturally, diamonds are made by carbon present at the depth of about 150 km, where pressure is 70,000 atm and the temperature is about 1500°C. These diamonds come up near the surface with special kimberlite rocks. Artifically, diamonds are made by heating graphite under high pressure in the presence of special catalysts.

Question 8.
Write the structure of graphite. Why is it so soft?
Answer:
Each carbon atom is bonded with three neighbouring carbon atoms with covalent bonds in graphite. They are always in the same plane giving hexagonal array. As compared to diamond, the distance between carbon atoms is more. The distance between upper and lower layers does not permit carbon atoms to make covalent bonds and because of this fourth electrons remains free. These layers can easily slide one upon the other and graphite attains the property of a lubricant. It is very soft and slippery.

Question 9.
Why are diamonds used in jewellery? Give reasons.
Answer:
Refractive index of diamond is 2.45 which is the highest of all known substances, because of this, it shines brightly. Its critical angle is 24°, which is very less. This is why, the light rays passing through it deviates much. A small deviation in it causes beautiful spectrum of colours. When the bases of diamond are polished, it produces an astonishing brightness. That is why diamonds are used in making jewellery.

Question 10.
Why is graphite a good conductor of electricity?
Answer:
Each carbon atom of graphite is surrounded by three carbon atoms joined with covalent bond which makes hexagonal layers over each other. In these layers distance between the carbon atoms is more, that is why the possibility of fourth covalent bond between the carbon atoms of opposite layers is reduced. The fourth covalent electron is set free. The graphite has easy flow of electrons and it acts as a good conductor of electricity.

Question 11.
What are the uses of graphite?
Answer:
Uses of Graphite

• It is good conductor of electricity so- it is used in making dry cells and electric arcs as electrods.
• It is used in making pencils, black colour and black paint.
• It has lubricant property so it is used in machines to keep them lubricating at high temperature.
• It is used in making crucibles to boil some metals because of its high melting point.

Question 12.
Why are allotropes of carbon in form a molecule known as fullerenes?
Answer:
The allotropes of carbon in which 60 carbon atoms join to form a molecule are termed as fullerene. US architect Buckminster Fuller designed three dimensional domes which were supported by pentagonal and hexagonal structures.

Since fullerene molecules looked like these domes, that is why they are known as fullerene.

Question 13.
Draw the electron dot structures of methane, ethane, ethene, butane.
Or
(i) Write molecular formula of butane.
(ii) Draw the structure of Propanal.
Answer:
Methane
Formula -CH₄

Ethane
Formula -C₂H₆

Ethene
Formula -C₂H₄

Or
(i) Butane
Formula – C₄H₁₀

(ii) Propanal

Question 14.
Write two tests of alcohol.
Answer:

1. Ester test: When alcohol is heated with acetic acid, in the presence of sulphuric acid, sweet smelling ester is produced.
2. Sodium test: Alcohol reacts with sodium metal and always produces hydrogen gas.

Question 15.
(a) What do you understand by homologous series? Explain with an example.
Answer:
Homologous series. A series of compounds in which the same functional group substitutes for hydrogen in a carbon chain is called a homologous series. Each successive member differ by (- CH₂) group. All the members of a homologous series can be obtained by similar process.

General Formula : C_nH_2n+2
For example : Homologous series of alkane is as follows

(b) Write the first three homologous compounds of methane.
Answer:
Homologous Compounds of Methane

Question 16.
Define homologous series. What are its main properties?
Answer:
Homologous series. A series of compounds in which the same functional group substitutes for hydrogen in a carbon chain is called homologous series. In this series the adjacent members differ by (-CH₂) group. Each member of a homologous series is called homolog.

Properties of Homologous Series :

• All the members of a homologous series can be represented by a common formula.
• Two successive members differ by one carbon atom and 2 hydrogen atoms.
• All the members of a homologous series possess similar chemical properties.
• There is a small difference between all the members of a homologous series.
• There is always a difference of 14 a.m.u. in atomic mass of two adjacent homologous.

Question 17.
What are alkanes? Write the properties of its main members. What do we conclude from its properties?
Answer:
Alkanes. The hydrocarbons with structural/general formula C_nH_2n+2 are called alkanes. The members of this group form an homologous series. Hydrocarbons like methane, ethane, propane and butane form many carbonic compounds which are collectively known as alkane. In these compounds, the number of carbon and hydrogen atoms differ by (- CH₂) for the next member of family.

Properties of Alkanes

Conclusions:

• Physical properties of alkane are based on their mass.
• First four members of alkane are in gasous state and alkanes having more than six carbon atoms are in liquid state.
• Alkanes having high molecular mass are found in solid state.
• Melting and boiling point of alkanes increase with increase in molecular mass.

Question 18.
What happens when hydrogen gas is passed through vegetable oils in the presence of nickel?
Answer:
Vegetables oils have double bond and polymerisation is possible. When nickel is used as catalyst, vegetable oil converts to vegetable ghee when hydrogen is passed through it because of hydrogenation. Vegetable ghee is solid like butter at room temperature.

Question 19.
Write the chemical properties of ethanoic acid.
Answer:
Ethanoic acid reacts with some metals, metal carbonates, hydroxides and bicarbonates.
1. Action with sodium:

2. Action with sodium hydroxide and potassium hydroxide:

3. Action with carbonate and hydrogen carbonate :
It reacts with carbonates and hydrogen carbonate to form water, salt and carbon dioxide.

Question 20.
Which type of oils should be used for cooking? Why?
Answer:
Animal fats have saturated fatty acids, which are harmful for health, whereas oils have long unsaturated carbon chains which are not harmful. Hence unsaturated fatty acids oils are used for cooking.

Question 21.
Write the ill-effects of using alcohol.
Answer:

• It is an addictive substance.
• It affects the sensitivity of nervous system.
• When a drunken person drives the vehicle he/she is not able to take the right decisions which leads to accident.

Question 22.
Why is consumption of methanol (CH₃OH) very fatal?
Answer:
Even a very small amount of methanol can prove fatal. In liver, it oxides to form methanale, which vigorously react with cells of liver, by which protoplasm gets emanating and swells in the same manner as boiled egg. Consumption of methanol also lead to blindness.

Question 23.
Write the IUPAC names of ethyl alcohol and acetic acid. Write the name of products formed when ethyl alcohol and acetic acid react in the presence of concentrated sulphuric acid. Write its chemical reaction.
Answer:

Compounds	IUPAC Names
1. Ethyl alcohol	ethanol
2. Acetic acid	ethanoic acid

Chemical reaction :

Question 24.
How will you prepare :
(a) ethyl alcohol from ethene
(b) acetic acid from ethyl alcohol?
Give reactions.
Answer:
(a) Ethene is heated with water in the presence of phosphoric acid to prepare ethyl alcohol

(b) Acetic acid is prepared by oxidation of ethyl alcohol

Question 25.
Write in brief the various industrial alcohols.
Answer:

• Absolute alcohol: It is 100% pure ethanol. It is produced by fractional distillation of ethanol which is prepared by fermentation of carbohydrates.
• Denatured alcohol: It is 95% ethanol and is used in industries. It is made poisonous by adding methanol, copper sulphate and pyridine, so as to make it unfit for drinking.
• Power alcohol: It is mixture of Benzene and Ether in 20% Ethanol and 50% gasolene. It is used to save petroleum.
• Alcoholic beverages: Alcohol is used as addictive drink. It is sold under various names like, rum, whisky, brandy, Jinn, etc.

Question 26.
Why is cleansing effect of soap not effective in hard water?
Answer:
Soaps are not effective in hard water for washing purposes because hard water has salts of calaium and magnesium. When soaps are dissolved in hard water, calcium and magnesium ions l’eact with water to form calcium and magnesium salts of fatty acids.

That is why a large amount of soap gets wasted. Calcium and magnesium salts being insoluble in water make precipitates and they get attached with the clothes and cause hinderance to the cleaning action and the clothes are not cleaned properly.

Question 27.
Distinguish between soaps and detergents.
Answer:

Soaps	Synthetic detergents
1. Soaps are sodium or potassium salts of higher fatty acids e.g. Sodium Stearate.	1. Synthetic detergents are Sodium alkyl Sulphates or Sodium alkyl benzene sulphates.
2. Soaps are prepared from vegetable oils or animal fats.	2. Synthetic detergents are prepared from the hydrocarbons obtained from petroleum.
3. Soaps have relatively weak cleansing action.	3. They have strong cleansing action.
4. Soaps form curdy white precipitates with calcium and magnesium salts present in hard water and hence, are not used in hard water.	4. Calcium and magnesium salts of detergents are soluble in water. Therefore no curdy white precipitates are obtained in hard water and hence synthetic detergents can be used even in hard water.
5. Soaps cannot be used in acidic medium as they are decomposed into carboxylic acids in acidic medium.	5. They can be used in acidic medium as they are the salts of strong acid and are not decomposed in acidic medium.
6. Soaps do not cause water pollution.	6. Synthetic detergents cause water pollution.
7. Soaps are biodegradable.	7. Some of the synthetic detergents are non biodegradable.

Question 28.
Write the formation of ethanol by fermentation process.
Answer:
Fermentation occurs in the presence of Bio-chemical catalysts at normal temperature by which sugar molecules convert into alcohol and carbon dioxide. These catalysts are known as enzymes, which means ‘yeast’ or ‘in the fermentation’.

Alcohol is formed by fermentation of sugar or starch. In a beaker, grape juice or glucose mixture is heated at 20° – 30°C in the presence of yeast. Sugar or starch molecules break into smaller molecules which produce carbon dioxide due to process of fermentation. This carbon dioxide is expelled out but air is not given inlet. A dilute mixture of ethanol is formed in water during fermentation. Ethanol is purified by distillation.

Chemical reaction :

Question 29.
Write the name of the reaction in which ethanoic acid and ethanol react together to form one product. Write the common name of the product.
Answer:
When ethanoic acid reacts with ethanol in the presence of concentrated sulphuric acid, ester is produced and this process is known as esterification.
CH₃COOH + C₂H₅OH → CH₃COOC₂H₅ + H₂O

Question 30.
Observe the figure given below :

(i) Write the reaction taking place
Answer:

(ii) What is this reaction called?
Answer:
Esterification

Question 31.
What is indicated in the figure given below and give use of it.
Answer:
The figure indicates formation of micelle. Micelles are used to remove oily dirt from clothes.
1 – Hydrophilic end
2 – Oil droplet.

Question 32.
Show the bonds of Hydrogen, Oxygen and Nitrogen atoms respectively.
Answer:
1. Hydrogen: Two atoms of hydrogen by sharing of their electrons make hydrogen molecule (H2).

2. Oxygen: A double bond is made between two atoms of oxygen. Each atom of oxygen shares two electrons with other atom to form .an octet.

3. Nitrogen: Each atom of nitrogen shares three electrons to form an octet.

Question 33.
(i) Write molecular formula of Propane.
Answer:
C3H8

(ii) Write IUPAC name of

Answer:
Bromoethane.

Question 34.
What is detergent? Write the formation of synthetic detergents. Write its advantage.
Answer:
Materials used for cleaning purposes are known as detergents. Since long, soaps have been used as detergents but now-a-days synthetic detergents are more popular. The detergent molecule has two ends, one which is made of sulphate (-SO₄) or sulphonate (SO₃Na) group and it is hydrophilic by nature whereas other which is made of hydrocarbon is hydrophobic.

Synthetic detergent produces ample amount of lather even in hard water. These do not form insoluble salts of calcium or magnesium.

Question 35.
Which substances are used to produce synthetic detergents?
Answer:
Following substances are needed for production of synthetic detergents :

• Long chained hydrocarbons obtained from petroleum and coal.
• Concentrated sulphuric acid.
• Sodium hydroxide.

Procedure: Hydrocarbons are treated with cone, sulphuric acid to get hydrocarbonic sulphuric acid. It is further reacted with NaOH which forms synthetic detergents. About 15 to 30% of the total weight of washing powder is detergent. Rest of the others are various chemicals which provide other qualities.

Question 36.
What are the components of washing powder?
Answer:

• Synthetic detergents (15 to 30%).
• Sodium sulphate and sodium nitrate.
• Sodium tri-poly phosphate or sodium carbonate.
• Sodium perborate.

Very Short Answer Type Questions

Question 1.
Which element is present necessarily in the following items?
Food, clothes, medicines and hooks.
Answer:
Carbon.

Question 2.
On which element do all living processes depend?
Answer:
Carbon.

Question 3.
What percentage of carbon is present in minerals found under the crust of earth?
Answer:
0.02 %.

Question 4.
What percentage of CO₂ is present in atmosphere?
Answer:
0.003%.

Question 5.
How many electrons are present in the outer shell of carbon?
Answer:
4.

Question 6.
Why does carbon need four electrons to gain or lose?
Answer:
To attain noble gas configuration.

Question 7.
How does carbon gain four electrons?
Answer:
By making C₄^– anion.

Question 8.
How does carbon lose four electrons?
Answer:
By making C₄⁺ cation.

Question 9.
Which type of bond is shared by a pair of two hydrogen atoms?
Answer:
Single bond.

Question 10.
How is single bond between two atoms expressed?
Answer:
By single straight line.

Question 11.
What is the atomic number of nitrogen?
Answer:
7.

Question 12.
How many electrons are given by each atom of Nitrogen to complete the octet?
Answer:
3.

Question 13.
Which gas is used as a fuel the most?
Answer:
Methane gas.

Question 14.
Methane is the main constituent gas of which two fuel gases?
Answer:
Biogas, C.N.G.

Question 15.
Write the full form of C.N.G.
Answer:
Compressed Natural Gas.

Question 16.
How is the structure of diamond?
Answer:
Strong three-dimensional structure.

Question 17.
How is the structure of graphite?
Answer:
Hexagonal.

Question 18.
Which of these two is a good conductor of electricity diamond or graphite?
Answer:
Graphite.

Question 19.
Which is the hardest substance?
Answer:
Diamond.

Question 20.
How does it feel by touching graphite?
Answer:
Soft and slippery.

Question 21.
Which element has the ability to form large number of compounds?
Answer:
Carbon.

Question 22.
Give names of two elements which are placed in the group of carbon and have same valency.
Answer:
Valency of carbon is 4. This group has silicon and germanium.

Question 23.
What is the simplest form of hydrocarbon?
Answer:
Methane (CH₄).

Question 24.
In which types of bonds can carbon atoms join?
Answer:
Single, double, triple bond and ring-shaped.

Question 25.
Write the names of five elements which can make bond with carbon to form new compounds.
Answer:
Oxygen, Hydrogen, Nitrogen, Sulphur, Chlorine.

Question 26.
Write the formula of Ethane.
Answer:
C₂H₆.

Question 27.
Write the structural formula of Ethane.
Answer:

Question 28.
Give the next higher homo-logues of:
(i) C₃H₆
Answer:
C₄H₈

(ii) C₆H₈.
Answer:
C₇H₁₀.

Question 29.
Give the structure of ethanol.
Answer:

Question 30.
Name the functional group in propanone.
Answer:

Question 31.
Give the structure of simplest ketone.
Answer:
Simplest keton is acetone. It has the structure :

Question 32.
Give the name and structure of four carbon atoms in aldehyde.
Answer:

Question 33.
Name the products obtained when ethanol undergoes complete combustion.
Answer:
Carbon dioxide (CO₂) and Water (H₂O).

Question 34.
Give the structural formula of ethanol.
Answer:

Question 35.
Give the name and structure of functional group present in acetic acid (CH3COOH).
Answer:
Carboxyl group

Question 36.
Which of the following compounds belong to same homo-Iogous series?
C₂H₆O₂, C₂H₆O₂, C₂H₆, CH₄O
Answer:
C₂H₆ O, (C₂H₅OH) And CH₄O or (CH₂OH).

Question 37.
Give the structural formula of an ester.
Answer:

Question 38.
Give the names and structural formulas of acid and alcohol from which ethyl acetate is obtained.
Answer:
Acetic acid

and ethyl alcohol, CH₃CH₂OH

Question 39.
Give the electron-dot stucture of methane.
Answer:

Question 40.
Define covalent bond.
Answer:
It is formed by mutual sharing of electron pair between two atoms.

Question 41.
Explain what covalent compounds do not conduct electric current?
Answer:
This is because there are neither free ions nor free electrons.

Question 42.
Name the bond formed between metal atom and non-metal atoms.
Answer:
Ionic or electro valent bond.

Question 43.
What are allotropes?
Answer:
When an element exists in two or more form having different physical pruperties but, some chemical properties, there forms are called allotropes.

Question 44.
Define catenation.
Answer:
It is the property due to which a large number of atoms of the same element get linked together through covalent bonds forming long straight chains, branched chains and rings of different sizes.

Question 45.
Give two oxidising agents.
Answer:

1. Acidified potassium permanganate.
2. Acidified potassium dichromate.

Question 46.
Give the electron dot structure of ethane.
Answer:
Dot structure of ethane :

Question 47.
Give the structural formula of propane.
Answer:

Question 48.
Give the electron dot structure of ethene.
Answer:
Dot structure of ethene.

Question 49.
Define functional group.
Answer:
It is an atom or group of atoms which when present in a molecule gives special properties to it. e.g. C₂H₅OH has the functional group, -OH (hydroxyl group).

Question 50.
If two organic compounds have some functional group, predict they have similar physical or chemical properties.
Answer:
Similar chemical properties.

Question 51.
Give the general formulae of alkanes, alkenes and alkynes.
Answer:
Alkanes: C_n H_2n+2
Alkaenes: C_nH_2n
Alkynes: C_nH_2n-2, where n = No. if carbon atoms).

Question 52.
Give the structural formula of isomers of C₄H₁₀ (butane).
Answer:
Butane has two structural isomers :

Question 53.
Give the first four members of homologous series of alcohols.
Answer:
CH₃OH, C₂H₅OH. C₃H₇OH, C₄H₅OH.

Question 54.
Define a Catalyst.
Answer:
It is a substance which can increase the rate of a reaction but remains unchanged in mass and composition at the end of reaction.

Question 55.
What happens when a piece of sodium metal is added to ethanol? Give chemical equation also.
Answer:

Question 56.
What happens when ethanol is heated with conc. H₂SO₄ at 443K?
Answer:
Ethanol undergoes acidic dehydration to give ethene

Question 57.
What is denatured spirit or alcohol?
Answer:
It is prepared by adding poisonous substance like methanol, acetone, pyridine or copper sulphate to ethanol. It is unfit for drinking purposes.

Question 58.
Give three uses of ethanoic acid.
Answer:

1. In the manufacture of vineger
2. In the manufacture white lead
3. As a reagent in laboratory.

Question 59.
What is the atomic number of hydrogen?
Answer:
One.

Question 60.
Give the electronic configuration of carbon atom.
Answer:
(2, 4).

Question 61.
Give name of four carbon compounds.
Answer:
Methane, Chloroform, Ethanol and ethanoic acid.

Question 62.
Give two allotropic forms of carbon.
Answer:
Diamond and graphite.

Question 63.
Give the name of simplest ketone.
Answer:
Propanone (CH₃ COCH₃).

Question 64.
Give the name of first member of homologous series of alkynes.
Answer:
Ethyne (C₂H₂).

Question 65.
Give the name and formula of acid present in vinegar.
Answer:
Ethanoic acid (CH₃ COOH).

Multiple Choice Questions:

Question 1.
Ethanoic acid has the formula:
(A) C₂H₅OH
(B) CH₃COCH₃
(C) CH₃COOH
(D) C₂H₅COOH.
Answer:
(C) CH₃COOH

Question 2.
Carboxylic acids contain functional group:
(A) -CHO
(B) -CH₂OH
(C) -COOH
(D) -OH.
Answer:
(C) -COOH

Question 3.
The general formula of the alkyne is:
(A) C_nH_2n-2
(B) C_nH_2n+2
(C) C_nH_2n
(D) C_nH_2n+2.
Answer:
(A) C_nH_2n-2

Question 4.
Propanone has the functional group :
(A) -OH
(B) -CHO
(C) C=O
(D) -COOH.
Answer:
(C) C=O

Question 5.
Vinegar contains acetic acid:
(A) 5-8%
(B) 15-20%
(C) 21-29%
(D) 30-40%.
Answer:
(A) 5-8%

Question 6.
The reaction of acetic acid with ethyl alcohol is called :
(A) Polymerisation
(B) Saponification
(C) Hydrogenation
(D) Esterification.
Answer:
(D) Esterification.

Fill in the Blanks :

Question 1.
The functional group present in ethyl alcohol is ___________
Answer:
The functional group present in ethyl alcohol is alcoholic group (-OH)

Question 2.
CH₃—CH₂—OH represents ___________
Answer:
Ethyl alcohol.

Question 3.
Two atoms of the same element combine to form a molecule. The bond between them is known as ___________ bond.
Answer:
Covalent.

Question 4.
In the formation of oxygen molecule, the oxygen atoms share ___________ electrons each.
Answer:
Two.

Question 5.
The number of single covalent bonds in the molecule of ammonia is ___________
Answer:
Three.

Punjab State Board PSEB 10th Class Science Book Solutions Chapter 4 Carbon and its Compounds Textbook Exercise Questions and Answers.

PSEB Solutions for Class 10 Science Chapter 4 Carbon and its Compounds

PSEB 10th Class Science Guide Carbon and its Compounds Textbook Questions and Answers

Question 1.
Ethane, with the molecular formula C₂H₆ has :
(a) 6 covalent bonds
(b) 7 covalent bonds
(c) 8 covalent bonds
(d) 9 covalent bonds.
Answer:
(b) 7 covalent bonds

Question 2.
Butanone is a four-carbon compound with the functional group :
(a) carboxylic acid
(b) aldehyde
(c) ketone
(d) alcohol.
Answer:
(c) ketone

Question 3.
While cooking, if the bottom of the vessel is getting blackened on the outside, it means that :
(а) the food is not cooked completely
(b) the fuel is not burning completely
(c) the fuel is wet
(d) the fuel is burning completely.
Answer:
(b) the fuel is not burning completely

Question 4.
Explain the nature of the covalent bond using the bond formation in CH₃Cl.
Answer:
The formation of CH₃Cl can be represented as :

Carbon forms single covalent bonds with three H- atoms and one Cl – atom by sharing one electron pair with each C-H bonds are non-polar. But C – Cl bond is polar because C and H leave almost same electronegativity whereas Cl has more electronegativity than carbon.

Question 5.
Draw the electron dot structures for :
(a) ethanoic acid
Answer:

(b) H₂S
Answer:

(c) propanone
Answer:

(d) F₂.
Answer:

Question 6.
What is an homologous series? Explain with an example.
Answer:
A series of compounds having similar structural formulae, same functional group and hence similar chemical properties is called a homologous series. In the homologous series any two adjacent members differ by CH2 unit in their molecular formulae.

For example homologous series of aldehydes (or alkanals) can be represented as :

H – CHO	Methanal
CH3 – CHO	Ethanal
CH3 – CH2 – CHO	Propanal
CH3 – CH2 – CH2 – CHO	Butanal
CH3 – CH2 – CH2 – CH2 – CHO	Pentanal and so on.

Question 7.
How can ethanol and ethanoic acid be differentiated on the basis of their physical and chemical properties?
Answer:
Differences between ethanol and ethanoic acid

Ethanol	Ethanoic acid
1. It is a colourless liquid having a pleasant smell.	1. It is colourless liquid having vineger like smell.
2. It has no action with a litmus solution.	2. It turns blue litmus solution red.
3. It has no action with sodium hydrogen carbonate solution.	3. It decomposes sodium hydrogen carbonate solution giving brisk effervescence of carbon dioxide gas.

Question 8.
Why does micelle formation take place when soap is added to water? Will a micelle be formed in other solvents such as ethanol also?
Answer:
Soap molecule has two ends, one is hydrophilic, and it dissolves in water, while the other end is hydrophobic, and it dissolves in hydrocarbons. When soap is at the surface of water , the hydrophobic ‘tail’ of soap will not be soluble in water and the soap will align along the surface of water with the ionic end in water and the hydrocarbon ‘tail’ pointing out of water.

Inside water, these molecules have a unique orientation which keeps the hydrocarbon portion out of the water. This is achieved due to the formation clusters of molecules in which the hydrophobic tails are in the interior of the cluster and the ionic ends are on the surface of the cluster. This formation is called a micelle.

Such micelles can be formed in other polar solvents like ethanol.

Question 9.
Why are carbon and its compounds used as fuels for most applications?
Answer:
Carbon and its compounds are used as fuels for most applications because they bum producing a large amount of heat and light.

Question 10.
Explain the formation of scum when hard water is treated with soap.
Answer:
When soap is added to hard water, the soluble calcium and magnesium salts present in it react with soap to give insoluble calcium salt of soap which produces scum.

Question 11.
What change will you observe if you test soap with litmus paper (red and blue)?
Answer:
Soap solution will turn red litmus paper blue because soap is alkaline in nature.

Question 12.
What is hydrogenation? What is its industrial application?
Answer:
The addition of hydrogen to unsaturated hydrocarbons in the presence of catalysts like palladium, platinum, nickel etc. to give saturated hydrocarbons is called hydrogenation.

This reaction is used for hydrogenation of liquid vegetable oils using a nickel catalyst to get artificial or vanaspati ghee.

Question 13.
Which of the following hydrocarbons undergo addition reaction : C₂H₆, C₃H₈, C₃H₆, C₂H₂ and CH₄.
Answer:
Out of C₂H₆, C₃H₈, C₃H₆, C₂H₂ and CH₄; C₃H₆ and C₂H₂ undergo addition reactions because they contain multiple bonds.

Question 14.
Give a test that can be used to differentiate chemically between butter and cooking oil.
Answer:
Distinction between Butter and Cooking oil:

Butter	Cooking Oil
1. It is solid at room temperature.	1. It is liquid at room temperature.
2. Mix equal volumes of HgCl2 solution in 50% alcohol and 5% iodine solution in alcohol. To this add lg of butter. Violet colour does not fade away.	2. Mix equal volumes of HgCl2 solution in 50% alcohol and 5% solution of iodine in alcohol. To this add 1 ml of cooking oil. Violet colour fades away.
3. Take 2 g of butter in a test tube. To this add 1ml of cone. HCl and a few drops of 2% furfural solution in alcohol. Shake and allow to stand for 5 – 10 minutes. No rose red coloration appears.	3. Take 2 g of cooking oil in a test tube. To this add 1 ml of cone. HCl and a few drops of 2% .furfural solution in alcohol. Shake it and allow to stand for 5 – 10 minutes. Rose red coloration is obtained.

Question 15.
Explain the mechanism of the cleansing action of soaps.
Answer:
Mechanism of cleansing action of Soap:
Soaps are sodium or potassium salts of higher fatty acids e.g. sodium palmitate, C₁₅H₃₁COO^–Na⁺, sodium stearate, C₁₇H₃₅COO^–Na⁺ etc. A molecule of soap consists of two parts :

1. a long chain hydrocarbon part (C₁₅H₃₁^–, C₁₇H₃₅ …. etc.) which is soluble in oil and
2. ionic part on polar group, – COO^–Na⁺ which is soluble in water. Thus a molecule of soap can be represented as :

The long hydrocarbon chain is insoluble in water but soluble in oil and greases whereas the ionic or polar part is soluble in water. Soap has a capacity to clean a dirty piece of cloth whereas ordinary water cannot. The dirty clothes contain greasy and oily substance (dirt). Soap molecules dissociate in water to give carboxylate ion (RCOO^–) and cation (Na⁺). When soap added to dirty clothes dipped in water, the hydrocarbon part of carboxylate group dissolving in greasy or oily dirt particles where the polar (COO^–) group remain attached to water. In this way each oil droplet acquires negative charge.

The cleansing action of Soap

These negative charged oil droplets called micelles cannot coalesce and hence form a stable emulsion water. These small droplets along with dirt can be easily washed away with water. Thus the soap helps in removing greasy dirt by producing a stable oil in wrater type emulsion. Also the soap reduces surface tension of water. Hence cloth is wetted more effectively and is cleaned.

Science Guide for Class 10 PSEB Carbon and its Compounds InText Questions and Answers

Question 1.
What would be the electron-dot structure of carbon dioxide which has the formula CO₂?
Answer:
In carbon dioxide, carbon atoms are bonded with two oxygen atoms. The atomic number of carbon is 6, and it has four electrons in the outer shell.

To make an octet it requires four electrons. Oxygen requires only two electrons in the outer shell. Therefore electron-dot structure will be :

Every oxygen atom is joined to carbon atom by double bond.

Question 2.
What would be the electron-dot structure of a molecule of sulphur which is made up of eight atoms of sulphur? (HINT. The eight atoms of sulphur are joined together in the form of ring.)
Answer:
The atomic number of sulphur is 16

Sulphur has 6 electrons in the outermost shell and to complete an octet it requires 2 electrons.
∴ Sulphur atom will share 2 electrons. It’s chemical formula is S₈.

Question 3.
How many structural isomers can you draw for pentane?
Answer:
Three ; n-Pentane, iso-pentane, neo-pentane.
Structural isomers can be drawn for pentane.

Question 4.
What are the two properties of carbon which lead to the huge number of carbon compounds we see around us?
Answer:

1. Catenation: The carbon atoms have an astonishing property to combine and form bond with other carbon atoms to form long chain compounds. This property is known as catenation. In this, either long chain of carbon are in ring form or the carbon atoms join in single, double or triple bond.
2. Tetravalency: Carbon has four electrons in the outermost shell. That is why its valency is four and it has got capacity to make bonds with other elements. Oxygen, Hydrogen, Nitrogen, Sulphur, Chlorine and many other elements can make new compounds with the help of carbon.

Question 5.
What will be the formula and electron dot structure of cyclopentane?
Answer:
Molecular formula of cyclopentane = C₅ H_{2 × 5} = C₅H₁₀

Question 6.
Draw the structures for following compounds :
Are structural isomers possible for bromopentane?
(i) Ethanoic acid
Answer:
Ethanoic acid (CH₃COOH)

(ii) Bromopentane
Answer:

Due to exchange of position of carbon with bromine, many isomers of bromopentane are possible.
For example :

(iii) Butanone
Answer:

(iv) Hexanal.
Answer:

Question 7.
How would you name the following compounds?
(i) CH₃ – CH₂ – Br
Answer:
Bromoethane

Answer:
Methanal

Answer:
Hex-1-yne.

Question 8.
Why is the conversion of ethanol to ethanoic acid an oxidation reaction?
Answer:
This is because in this reaction oxygen gets added to ethanol.

Question 9.
A mixture of oxygen and ethyne is burnt for welding. Can you tell why a mixture of ethyne and air is not used?
Answer:
A mixture of ethyne and air is not burnt for welding. This is because air also contains nitrogen along with oxygen. Nitrogen will also burn in oxygen producing oxides of nitrogen such as nitre oxide (NO) and nitrogen dioxide (NO₂) which cause pollution.

Question 10.
How would you distinguish experimentally between an alcohol and a carboxylic acid?
Answer:
The following two tests are used :

• Litmus test: Treat the given compound with blue litmus solutions. If the blue litmus solution turns red, it is a carboxylic acid and if does not turn red, it is an alcohol.
• Sodium bicarbonate test: Add some sodium bicarbonate solution to the given compound. If their is a brisk evolution of a colourless and odourless gas (CO₂) which turns freshly prepared lime water milk, it is carboxylic acid and if their is no effervescence, it is an alcohol.

Question 11.
What are oxidising agents?
Answer:

• The substances which can oxidise other substances by giving oxygen are called oxidising agents.
• Examples: Alkaline potassium permanganate solution, acidified potassium dichromate solution, etc.

Question 12.
Would you be able to check if water is hard using a detergent?
Answer:
No, we can’t check whether the water is hand or soft using a detergent.

Question 13.
People use a variety of methods to wash clothes. Usually after adding the soap, they ‘beat’ the clothes on a stone, or beat it with a paddle, scrub with a brush, or the mixture is agitated necessary to get clean clothes?
Answer:
This is because when soap molecules dissolve in the dirt, the dirt is somewhat loosened from the clothes, and in order to remove it from clothes, the clothes have to be beaten on a stone or beaten with a paddle or scrubbed with a brush or mixture has to be agitated in washing machines.

Punjab State Board PSEB 10th Class English Book Solutions English Main Course Book Chapter 2 Where is Science Taking Us? Textbook Exercise Questions and Answers.

PSEB Solutions for Class 10 English Main Course Book Chapter 2 Where is Science Taking Us?

Short Answer Type Questions

Question 1.
Why does the author of ‘Where Is Science Taking Us ? say that science is doing less than nothing ?
Answer:
Science has done nothing with regard to ethical and spiritual matters. It has created many ethical problems, but doesn’t offer any solutions. Therefore, the writer says that science is doing less than nothing.

नैतिक और आध्यात्मिक विषयों के सम्बन्ध में विज्ञान ने कुछ नहीं किया है। इसने अनेक नैतिक समस्याएं खड़ी कर दी हैं, परन्तु उनका समाधान नहीं दिया है। इसलिए लेखक कहता है कि विज्ञान कुछ भी नहीं से भी कम कर रहा है।

Question 2.
What are machines doing for the humans ?
Answer:
Machines have given humans abnormal power. They are helping them in every field. They are working as man’s slaves.

मशीनों ने मनुष्यों को असाधारण शक्ति प्रदान कर दी है। वे हर क्षेत्र में उनकी सहायता कर रही हैं। वे मनुष्य के दासों के रूप में काम कर रही हैं।

Question 3.
What is the greatest triumph of science ?
Answer:
Science has helped us to produce more and more food. It has also invented many new medicines and helped man to live longer.

विज्ञान ने अधिकाधिक भोजन पैदा करने में हमें सहायता प्रदान की है। इसने अनेक नई दवाइयों का आविष्कार भी किया है और मनुष्य की अधिक समय तक जीवित रहने में सहायता की है।

Question 4.
What are the consequences of war ?
Answer:
War causes death and destruction. Selfish traders hoard all food and people have to starve.

युद्ध से मृत्यु और विनाश पैदा होते हैं। स्वार्थी व्यापारी सभी खाने की चीज़ों की जमाखोरी कर लेते हैं और लोगों को भूखा मरना पड़ता है।

Question 5.
Today the upper age group is overcrowded.’ Why?
Answer:
Almost every year, many new drugs are invented. These drugs increase the average span of life. As a result of this, the upper age group has become overcrowded.

लगभग प्रत्येक वर्ष अनेकों नई दवाइयों की खोज हो जाती है। ये दवाइयां जीवन की औसत अवधि को बढ़ा देती हैं। इसके परिणामस्वरूप अधिक आयु के लोगों की संख्या अत्यन्त बढ़ गई है।

Question 6.
What has happened to the ethics and morals in the modern world?
Answer:
In the modern world, everybody is running after material things. Nobody cares about ethics and morals.

आधुनिक संसार में प्रत्येक व्यक्ति भौतिक चीजों के पीछे भाग रहा है। नैतिकता और नीति-शास्त्र की परवाह कोई नहीं करता है।

Question 7.
What is really needed in the world today ?
Answer:
Moral and spiritual values are needed in the world today. The qualities of charity, mercy, understanding, tolerance and justice need to be developed.

आज संसार में नैतिक और आध्यात्मिक मूल्यों की ज़रूरत है। दान, दया, सहानुभूति, सहनशीलता और न्याय सम्बन्धी गुणों को विकसित करने की ज़रूरत है।

Question 8.
Why does the author of ‘Where Is Science Taking Us ? wish to live another hundred years ?
Answer:
The author hopes that life will become more interesting, intriguing and exciting in future. He wants to enjoy such kind of life. That is why he wishes to live another hundred years.

लेखक को आशा है कि भविष्य में जीवन और अधिक रोचक, जटिल और रोमांचक हो जाएगा। वह इस प्रकार के जीवन का आनन्द उठाना चाहता है। इसी कारण से वह सौ वर्ष और जीना चाहता है।

Long Answer Type Questions

Question 1.
List the material triumphs of science and the non-material necessities to make the world a better place.
Answer:
Science has given man all power over the physical world. It has given man the power of machines. With the help of machines, man can do even the impossible. But science has given man only the power over material things. In fact, it is the non-material things like charity, mercy, tolerance and justice that make the world a better place. In this regard, science has done less than nothing.

विज्ञान ने मनुष्य को भौतिक संसार के ऊपर पूरी शक्ति प्रदान कर दी है। इसने मनुष्य को मशीनों की शक्ति प्रदान कर दी है। मशीनों की सहायता से मनुष्य असम्भव काम तक कर सकता है। किन्तु विज्ञान ने मनुष्य को केवल भौतिक चीज़ों के ऊपर शक्ति प्रदान की है। वास्तव में यह दान, दया, सहनशीलता और न्याय जैसी चीजें हैं जो संसार को एक बेहतर जगह बनाती हैं। इस विषय में विज्ञान ने कुछ नहीं से भी कम काम किया है।

Question 2.
What should be the ultimate aim of science ?
Answer:
The ultimate aim of science should be to make life worthwhile on the earth. No doubt, science has given man the comfort of all material things. But more than material things, it is the non-material things that man needs. They are the qualities of charity, mercy, tolerance and justice. It is these things that make life worthwhile. Science should help man develop these functions of the mind.

विज्ञान का अन्तिम लक्ष्य इस धरती पर जीवन को सार्थक बनाना है। निस्सन्देह विज्ञान ने मनुष्य को सभी भौतिक चीज़ों की सुविधा प्रदान की है। किन्तु भौतिक चीजों से ज्यादा मनुष्य को अभौतिक चीज़ों की ज़रूरत है। वे दान, दया, सहनशीलता और न्याय के गुण हैं। यही चीजें हैं जो जीवन को सार्थक बनाती हैं। विज्ञान को मनुष्य में यही क्रियाएँ विकसित करने में सहायता देनी चाहिए।

Vocabulary and Grammar

Question 1.
Modern drugs have decreased the average span of life of human beings. (True, False)
Answer:
False

Question 2.
Machines give us more and more hours of …………..
(i) hard work
(ii) leisure
(iii) life
(iv) health.
Answer:
(ii) leisure

Question 3.
Name two non-material things mentioned in the lesson.
Answer:
Charity and tolerance

Question 4.
According to the writer, science is doing ‘less than nothing for material things’. (True, False)
Answer:
True

Question 5.
Which age group is overcrowded today?
(i) Childhood
(ii) Middle age group
(iii) Upper age group
(iv) None of these.
Answer:
(iii) Upper age group

Question 6.
Science has helped man to live ……
(i) forever
(ii) no more
(iii) longer
(iv) a short life.
Answer:
(iii) longer

Answer each of the following in one word / phrase / sentence :

Question 1.
Name the author of the essay, Where is Science Taking Us’?
Answer:
The name of the author is Dr. S.W. Pennyquick.

Question 2.
Which is the newer question cropping up before us ?
Answer:
The question is : ‘Where is science taking us ?

Question 3.
Which thing does the author first take as a material thing ?
Answer:
He first takes up the machine as a material thing.

Question 4.
Where do we find machines ?
Answer:
We find them in every sphere of life.

Question 5.
What does a machine give us ?
Answer:
A machine gives us power and leisure.

Question 6.
Are machines good for us in all the ways ?
Answer:
No, they also create problems for us.a

Question 7.
What questions regarding machines come in man’s mind ?
Answer:
Man wants to know the answer regarding the aims and goal of the machines.

Question 8.
What things are now most important for the humanity ?’
Answer:
They are understanding, tolerance, justice and mercy.

Question 9.
Has science been successful in non-material things ?
Answer:
No, science has been helpless in this regard.

Question 10.
How is the life becoming because of machines ?
Answer:
It is becoming more and more interesting and exciting.

Complete the following :

1. Material things are our ………………… business.
2. Machines are there in every …………………. of human activity.
3. This age is truly the age of ………………….
4. We can now kill our fellow men in …………………. numbers.
5. During the war, many people have to …………………
6. Machine age gives us more hours of …………..
Answer:
1. daily
2. field
3. machine
4. large
5. starve
6. leisure.

Write True or False against each statement :

1. From the early times, man has wanted to know the meaning of life.
2. Science is doing a lot in respect of ethical and spiritual values.
3. Machines have reduced our leisure time.
4. Science produces goods, but it has no control over the consequences.
5. The number of aged persons has come down.
6. The spirit of tolerance and understanding is necessary for the humans.
Answer:
1. True
2. False
3. False
4. True
5. False
6. True.

Choose the correct option for each of the following:

Question 1.
Man has always wanted to know the ………………… of life.
(a) use
(b) meaning
(c) complexities
(d) mystery
Answer:
(b) meaning

Question 2.
Machines have given us more hours of ……………
(a) worries
(b) troubles
(c) leisure
(d) hard work.
Answer:
(c) leisure

Question 3.
We can now kill our fellow beings in …………
(a) fewer numbers
(b) a second
(c) the trenches
(d) larger numbers.
Answer:
(d) larger numbers.

Question 4.
Now the wars have become ……
(a) very terrible
(b) easy
(c) rare
(d) impossible.
Answer:
(a) very terrible

Objective Type Questions

Question 1.
The synonym of each word under column A rhymes with the other word given under column C. Fill in the blanks in column B with the synonyms of words under A :
Answer:
1. fury – rage – page
2. began-started – parted
3. consequence – result – insult
4. conquest – victory – history
5. ethical – moral – oral
6. apparent – obvious – tedious
7. tolerate – bear – tear
8. charity – donation – nation
9. sufficient – enough – rough
10. abolish – end – mend.

Question 2.
Match the words under A with their antonyms under B :
Answer:
1. material → spiritual
2. forward → backward
3. necessary → unnecessary
4. creative → destructive
5. triumph → defeat
6. less → more
7. obvious → latent
8. ultimate → initial
9. justice → injustice
10. exciting → dull.

Question 3.
Make meaningful words by using over and under as prefix or suffix.
Answer:
1. overcome
2. underline
3. overestimate, underestimate
4. overstatement, understatement
5. undercurrent
6. overarm, underarm
7. overdo
8. overground, underground
9. pullover
10. overage, underage
11. underpants
12. overcharge, undercharge.

Question 4.
Rewrite the following in Direct Speech :
Answer:
1. The minister said, “I spoke about the rights of the citizens in a democracy. I must speak about the citizen’s responsibilities too.”
2. My mother said to me, “Do not waste your time during the holidays. Do some useful reading.”
3. The school inspector said, “I was very pleased with the school. I wish to congratulate the principal and the staff.”
4. The boys said to the teacher, “We didn’t understand the question. Please explain it once more.”

Question 5.
Change the Voice in the following sentences :
Answer:
1. The examination has been passed by him.
2. The truth must be spoken by you.
3. Your uncle’s advice should be followed by you.
4. A song can be sung by her now.
5. The test will be passed by Ram.
6. Why was he abused by you ?
7. It has to be done by me.
8. The police will arrest him soon.
9. A lie cannot be told by her.
10. You must accept this.

Question 6.
Put the words in the brackets into the be-going form :
Answer:
1. You are going to miss your bus.
2. The man with a brick in his hand is going to throw it at the dog.
3. We are wearing red clothes and the bull is going to attack us.
4. I am not going to sleep in this room, it is dirty.
5. Due to some technical fault, the aeroplane is going to crash.
6. They are going to make a lot of money out of this deal.
7. I am going to collect my new dress this evening.
8. I’ve reminded you once; I am not going to do it again.
9. He is going to smuggle this gold out of the country.
10. Look at the clouds. It is going to rain.

Where is Science Taking Us? Summary & Translation in English

Where is Science Taking Us Introduction:

In this chapter, the writer analyses the aims and the ultimate goal of science. He says that science has so far limited itself to material things. It has given man immense power over his material environment. But in non-material things such as charity, tolerance, forbearance, justice, mercy and understanding – science has been helpless. The writer says that the ultimate goal of science should be to make life worthwhile. And it can be done only by the advancement of non-material things. The writer hopes that one day science will bring about a functional improvement in the human mind and give it greater power of reasoning and understanding. He hopes that man will then have sufficient reason and understanding to abolish war.

Where is Science Taking Us? Summary & Translation in English:

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When man first began to think, he asked himself the deepest of all questions a question which you have undoubtedly asked yourself many times : What is the Meaning of Life ? What is it all about ? Where are we all going ? What drives men ever forward to work and worry ? And now there’s this other big question a newer question which is beginning to force itself into our notice. One that is not ages old that has not been with us since man first began to think. It is : Where is Science Taking Us?

First, where is science taking us with regard to ethical and spiritual values ? We know what it is doing with regard to material things, for material things are its daily business; but what is it doing with regard to non-material things ? If the answer were ‘nothing at all’, that would be bad enough; but the actual answer is ‘less than nothing’. Here science is actually doing less than nothing. Its material teachings have been so over-emphasized that many people are floundering and wondering whether after all man is but a machine animated by forces over which he has no control.

Let’s concentrate on material things, the things that form the very stronghold of science. Look at the machine, for instance. This is the age of the machine. Machines are everywhere in the fields, in the factory, in the home, in the street, in the city, in the country, everywhere. To fly, it is not necessary to have wings; there are machines. To swim under the sea it is not necessary to have gills ; there are machines. To kill our fellow men in overwhelming numbers, there are machines. Petrol machines alone provide ten times more power than all human beings in the world. In the busiest countries, each individual has six hundred human slaves in his machines.

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What are the consequences of this abnormal power ? Before the war, it looked as though it might be possible, for the first time in history, to provide food and clothing and shelter for the teeming population of the world every man, woman and child. This would have been one of the greatest triumphs of science. And yet, many a time especially during the war we have seen the world crammed full of food and people hungry. For that’s the way of science and the machine age. Science produces the goods, it makes the goods, but has no control over the consequences.

The machine age gives us year by year more hours of leisure but it fails to teach us how to use them. It gives us mechanical habits of mind and represses the spirit of adventure except along machine- made lines. We will need all our creative powers to think our way out of the social problems which science has created for us.

It is science that has given us the unexpected redistribution of the age groups. Almost every year, some modern drug adds a little more to the average span of life, until the upper group is overcrowded. In the United States, for instance, there are already nine million people over the age of sixty. (This talk was delivered around the 1950’s.) In fifteen years’ time, this number will reach the astonishing figure of forty-five million. Who is to keep them ? It will need some readjustment.

And so science goes on raising its problems. Compared with our fundamental question What is Life ? these problems may seem to be of less importance. But they are not really so.

What is happening is that science is creating problems faster than they can be solved. Man is struggling in a sort of vicious circle, always striving to catch up and never getting nearer. And there are no signs that the glut of discoveries is coming to an end. War is the worst example; science has pushed it so far forward that ethics 1 and morals are floundering hopelessly behind.

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It makes one sometimes ask : What is science really after? What are its aims? What is its goal? Its aims seem to be obvious. They are material, of course. One aim is the complete understanding, indeed the conquest, of man’s environment ; the conquest of everything material, big or small, bringing all powers within man’s reach. The other aim is the understanding of all the mysteries that lie within the human body the material mysteries, the innumerable chemical and physical actions that make the body work.

If these are the apparent aims of science, surely they cannot represent the ultimate goal. The ultimate goal, if there is such a thing, must be the understanding of everything that makes life worth while, the enrichment of all that life means. That goes beyond material things; for man needs more than food and shelter and clothing and the understanding of what goes on within his stomach.

What is really needed in the world today, perhaps more than ever before, is not some new world-shattering discovery in nuclear physics, or some breath taking discovery in chemistry or medicine. The advance for which the world is waiting, beyond any doubt, is a small advance a slight advance in charity, in understanding, forbearance, tolerance, justice and mercy. That is what the world is waiting for, and waiting rather anxiously. But charity, and tolerance, and forbearance, and the understanding of one another are non-material matters. And in non-material things in the simplest social things science has been helpless. It cannot even help us to distinguish good from evil.

Maybe this will not always be so. Who knows ? It is quite probable that some day science will effect an improvement in the human brain itself. Not a structural improvement, for in structure the human brain is the greatest miracle of all; its understanding will come last. But there might well be a functional improvement. That is far from fantastic. The advances in science might one day well increase the capacity and reasoning power of the human brain.

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I should say there is little doubt that man will one day improve on the natural man, raise his intellectual status, and give himself greater power of reasoning and understanding. He might have sufficient reason and understanding to abolish war. Whether that will be so, whether and when he will have a better understanding of his fellow men that remains to be seen. It brings us back to the question Where is Science Taking Us ? Despite the present vicissitudes, we are going somewhere. There are trouble some times ahead. But those who fear for the future are the craven (cowardly) in spirit; for life is becoming more and more interesting, intriguing and exciting. I wish I had another hundred years

Where is Science Taking Us? Summary & Translation in Hindi

Where is Science Taking Us? Introduction:
इस लेख में लेखक विज्ञान के उद्देश्यों तथा इसके अन्तिम लक्ष्य का विश्लेषण करता है। वह कहता है कि विज्ञान ने अब तक स्वयं को भौतिक चीज़ों तक ही सीमित रखा है। इसने मनुष्य को अपने भौतिक पर्यावरण पर अथाह शक्ति प्रदान की है। किन्तु दयालुता, सहनशीलता, धैर्य, न्याय, दान-भावना तथा सहानुभूति जैसी अभौतिक चीज़ों के बारे में विज्ञान असहाय है। लेखक कहता है कि विज्ञान का अन्तिम लक्ष्य जीवन को सार्थक बनाना होना चाहिए तथा ऐसा केवल अभौतिक चीजों को विकसित करने से ही सम्भव हो सकता है। लेखक आशा करता है कि एक दिन विज्ञान मनुष्य के दिमाग की कार्य-प्रणाली में सुधार ला देगा। यह इसे तर्क करने तथा दूसरों को समझ पाने के लिए अधिक योग्यता प्रदान कर देगा। वह आशा करता है कि मनुष्य के पास तब इतना तर्क और इतनी सहानुभूति होगी कि युद्ध सदा के लिए समाप्त हो जाएगा।

Where is Science Taking Us? Summary & Translation in Hindi:

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जब मनुष्य ने पहली बार सोचना शुरू किया तो उसने सभी प्रश्नों से अधिक गहराई वाला एक प्रश्न स्वयं से पछा – वह प्रश्न जो आप ने निश्चय ही स्वयं से अनेक बार पछा होगा जीवन का अर्थ क्या है ? वह सब किसके विषय में है ? हम सब कहां जा रहे हैं ? कौन-सी चीज़ मनुष्यों को हमेशा आगे की तरफ धकेलते हुए काम करने और चिन्ता करने के लिए धकेलती रहती है ? और अब वहां यह दूसरा बड़ा प्रश्न है – एक और नया प्रश्न जो हमारे ध्यान में ज़बरदस्ती आना शुरू हो / गया है। ऐसा प्रश्न जो युगों पुराना नहीं है ……. जो | हमारे पास तब से नहीं रहा है जब से मनुष्य ने पहली

बार सोचना शुरू किया था। यह प्रश्न है – विज्ञान हमें कहां ले जा रहा है ? पहली बात यह है कि विज्ञान हमें नैतिक और आध्यात्मिक गुणों के विषय में हमें कहां ले जा रहा है ? हमें पता है कि यह भौतिक पदार्थों के विषय में क्या कर रहा है, क्योंकि भौतिक चीजें इसकी दैनिक क्रिया में आती हैं ; किन्तु यह अभौतिक चीज़ों के सम्बन्ध में क्या कर रहा है ? यदि इसका उत्तर होता ‘कुछ भी नहीं’, तो यह बहुत खराब बात होती; किन्तु वास्तविक उत्तर है – ‘कुछ नहीं से भी कम’। इस क्षेत्र में विज्ञान वास्तव में कुछ नहीं से भी कम कर रहा है। इसकी भौतिक शिक्षाओं को इतना ज्यादा वज़न दिया गया है कि अनेक लोग भटकने लगे हैं और हैरान हुए  सोच रहे हैं कि आखिर क्या मनुष्य मात्र एक मशीन है| जो ऐसी शक्तियों के द्वारा संचालित हो रही है जिनके ऊपर उसका कोई वश नहीं है।

आइए, हम भौतिक चीज़ों पर अपना ध्यान एकाग्र | करें, वे चीजें जो विज्ञान का केन्द्र हैं। उदाहरण के रूप में, मशीन को देखिए।यह मशीन का युग है। मशीनें हर जगह हैं – खेतों में, फैक्टरियों में, घरों में, शहर में, गलियों में, देहात में,| हर जगह। उडने के लिए पंखों की ज़रूरत नहीं: इसके लिए मशीनें हैं। समुद्र के भीतर तैरने के लिए गलफड़ों की ज़रूरत नहीं है। इसके लिए मशीनें हैं। अपने साथी मानव-जीवों को भारी संख्या में मारने के लिए वहां. मशीनें हैं। अकेली पेट्रोल की मशीनें ही दुनिया भर के सभी मनुष्यों की अपेक्षा दस गुणा अधिक शक्ति प्रदान / करती हैं। व्यस्ततम् देशों में प्रत्येक व्यक्ति के पास | उसकी मशीनों के रूप में छ: सौ गुलाम हैं।

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इस असामान्य शक्ति के क्या परिणाम हैं ? युद्ध के पहले ऐसा प्रतीत होता था मानो इतिहास में पहली बार विश्व की उमड़ती जनसंख्या को खाना, कपड़े और | रहने के लिए छत दे पाना शायद सम्भव | हर आदमी, औरत और बच्चे के लिए। विज्ञान की यह हो जाएगा सबसे बड़ी जीत होनी थी। और फिर भी हमने कई बार, विशेषकर युद्ध के दौरान, विश्व में भोजन से ठसाठस भरे हए भंडार देखे हैं और लोगों को भखे रहते देखा है। क्योंकि यही तरीका है विज्ञान और मशीनी युग का। विज्ञान चीज़ों का उत्पादन करता है, वह चीजें बनाता है, किन्त परिणामों पर इसका कोई नियंत्रण नहीं है। मशीनी युग हमें वर्ष-प्रति-वर्ष विश्राम के अधिकाधिक घण्टे प्रदान करता है किन्तु हमें इस विश्राम का उपयोग करना नहीं सिखाता है।

यह हमारे दिमाग को एक मशीन के जैसी आदतें प्रदान कर देता है और साहसिक भावना को दबा देता है – मशीनी ढंग से काम करने के अतिरिक्त शेष सभी भावनाओं को। हमें अपनी सभी सृजनात्मक शक्तियों का प्रयोग करते हुए सोचना होगा कि हम उन सामाजिक समस्याओं से कैसे बाहर निकल सकते हैं जो विज्ञान ने हमारे लिए पैदा कर दी हैं। यह विज्ञान है जिस ने हमें आयु-वर्गों का अप्रत्याशित रूप से पुनः वर्गीकरण प्रदान कर दिया है। लगभग प्रति वर्ष कोई न कोई आधुनिक दवाई जीवन की औसत अवधि को थोडा और बढ़ा देती है. जिस से ऊपरी आयु-वर्ग की संख्या और भी ज्यादा हो जाती है। उदाहरण के रूप में, संयुक्त राज्य में साठ वर्ष से अधिक आयु वाले लोग पहले ही 90 लाख हैं।

(यह भाषण 1950 के आसपास दिया गया था।) पन्द्रह वर्षों केसमय में यह संख्या साढ़े चार करोड़ के अचम्भाजनक आँकड़े तक पहुँच जायेगी। उनका पालन कौन करेगा ? इसके लिए कुछ पुनः समन्वय करने की ज़रूरत पड़ेगी। तथा इस प्रकार विज्ञान अपनी समस्याएँ पैदा करता रहता है। हमारे मौलिक प्रश्न के मुकाबले में – कि ज़िन्दगी क्या है ? ये समस्याएं शायद थोड़ी कम महत्त्वपूर्ण लगें। परन्तु वास्तव में वे ऐसी नहीं हैं। सुलझाया नहीं जा सकता। मनुष्य एक प्रकार के दुश्चक्र में संघर्ष कर रहा है, हमेशा समस्याओं से निबटने का संघर्ष करता रहता है और कभी भी उनके बराबर आगे बढ़ नहीं पाता है। और इस बात के कोई संकेत नहीं है कि आविष्कारों की भरमार समाप्त होने वाली है। सबसे| बुरा उदाहरण युद्ध है; विज्ञान ने इसे इतना आगे धकेल दिया है कि नीतिशास्त्र और नैतिकता बेबस रूप से भटकते हुए पीछे रह गए हैं।

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इस कारण कभी-कभी व्यक्ति पूछने लगता है विज्ञान वास्तव में क्या प्राप्त करना चाहता है ? इसके उद्देश्य क्या हैं ? इसका अन्तिम लक्ष्य क्या है ? इसके लक्ष्य स्पष्ट लगते हैं। वे निस्सन्देह भौतिक हैं। एक लक्ष्य है : पूर्ण समझ, असल में विजय, इन्सान की उसके वातावरण पर विजयः प्रत्येक भौतिक चीज़ पर विजय, बड़ी हो या छोटी, सभी शक्तियों को मनुष्य की पहुंच के अंदर लाना।दूसरा उद्देश्य उन सभी रहस्यों को समझना है जो मनुष्य के शरीर के भीतर छिपे हैं – भौतिक रहस्य, वे असंख्य रासायनिक और शारीरिक क्रियाएं जो शरीर को चलाने में मदद करती हैं। यदि विज्ञान के प्रत्यक्ष उद्देश्य यही हैं तो निस्सन्देह वे अन्तिम उद्देश्य नहीं हो सकते।

अन्तिम उद्देश्य, यदि ऐसी कोई चीज़ होती है, तो यह अवश्य उन सभी बातों की समझ होनी चाहिए जो जीवन को सार्थक बनाती हैं, उन सभी बातों की समृद्धि जिनका अर्थ जीना होता है। यह बात भौतिक चीज़ों से परे की बात है; क्योंकि मनुष्य को रोटी, कपड़ा और मकान से कुछ ज्यादा चाहिए होता है और ऐसी बातों की समझ से कुछ ज्यादा कि उसक पट म क्या गातावाधया चल रही होती हैं।

आज की दुनिया में वास्तव में जिस चीज की आवश्यकता है, शायद पहले के किसी समय से भी ्यादा, वह परमाणु भौतिकी के किसी विश्व-विनाशक आविष्कार की नहीं है, अथवा रसायन-विज्ञान या औषधि विज्ञान में किसी आश्चर्यजनक खोज की। वह प्रगति, जिसकी संसार प्रतीक्षा कर रहा है वह निस्संदेह एक छोटी-सी प्रगति है सिर्फ थोड़ी-सी प्रगति दानशीलता, समझ, धैर्य, सहनशीलता, न्याय और दया भावना में प्रगति। यही चीज़ है जिसका इंतजार दुनिया कर रही है, और बहुत उत्सुकता से। किन्तु दानशीलता और सहनशीलता और धैर्य तथा परस्पर समझ अभौतिक चीजें हैं। और अभौतिक चीजों

के विषय में अति साधारण सामाजिक बातों के सम्बन्ध में विज्ञान बेबस रहा है। यह तो बुराई और अच्छाई में अंतर करने में भी हमारी मदद नहीं कर सकता। शायद ऐसा हमेशा नहीं रहेगा। कौन जानता है ? ऐसी बहुत सम्भावना है कि विज्ञान किसी दिन इन्सानी दिमाग़ में ही सुधार ला दे। दिमाग़ की बनावट में नहीं, क्योंकि आकार की दृष्टि से इन्सानी दिमाग एक सब से बड़ा अजूबा है; इसे समझ पाना सब से अन्तिम बात होगी। किन्तु इस में क्रियात्मक सुधार लाया जा सकता है। यह कोई बहुत विलक्षण बात नहीं है। विज्ञान में होने वाली प्रगतियां शायद एक दिन मानव दिमाग़ की क्षमता और इसकी तर्क-शक्ति को भी बढ़ा दें।

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मैं तो कहूंगा कि इस बात में लगभग कोई सन्देह नहीं है कि मानव अपने स्वाभाविक रूप से बेहतर बन जाएगा, अपने बौद्धिक स्तर को ऊपर उठा लेगा, तथा स्वयं को तर्क करने और समझने की बेहतर शक्ति प्रदान कर देगा। उसके पास शायद इतना तर्क और इतनी बुद्धि आ जाए कि वह युद्ध को समाप्त कर दे। क्या ऐसा होगा, क्या उसे अपने सहजीवों के बारे में बेहतर समझ प्राप्त हो जाएगी और कब होगी ये बातें अभी देखना बाकी इस से हम पुनः वापस उस प्रश्न पर आ जाते हैं कि विज्ञान हमें कहां ले जा रहा है ? वर्तमान के उतार चढ़ावों के बावजूद हम किसी-न-किसी तरफ़ अग्रसर हो रहे हैं। आने वाला समय मुश्किलों से भरा होगा। किन्तु वे लोग जो भविष्य के विषय में डरते हैं, वे आत्मा के कायर हैं, क्योंकि जीवन अधिकाधिक रुचिपूर्ण, जटिल और रोमांचक होता जा रहा है। काश, मेरे पास (जीवन के) एक सौ वर्ष और होते।

 

Punjab State Board PSEB 10th Class Science Book Solutions Chapter 6 Life Processes Textbook Exercise Questions and Answers.

PSEB Solutions for Class 10 Science Chapter 6 Life Processes

PSEB 10th Class Science Guide Life Processes Textbook Questions and Answers

Question 1.
The kidneys in human beings are a part of the system for :
(a) nutrition
(b) respiration
(c) excretion
(d) transportation.
Answer:
(c) excretion.

Question 2.
The xylem in plants are responsible for :
(a) transport of water
(b) transport of food
(c) transport of amino acids
(d) transport of oxygen.
Answer:
(a) transport of water.

Question 3.
The autotrophic mode of nutrition requires :
(a) CO₂ and water
(b) Chlorophyll
(c) Sunlight
(d) All of the above.
Answer:
(d) All of above.

Question 4.
The breakdown of pyruvate to give CO₂, water and energy takes place in :
(a) cytoplasm
(b) mitochondria
(c) chloroplast
(d) nucleus
Answer:
(b) mitochondria.

Question 5.
How are fats digested in our bodies? Where does the process take place?
Answer:
Digestion of fats takes place in the intestine. The fats are emulsified by the bile salts present in bile. The emulsified fats are acted upon by pancreatic lipase (strepsin) which hydrolyses fats into fatty acids and glycerol. The intestinal lipase also hydrolyses the emulsified fats into fatty acids and glycerol.

Question 6.
What is the role of saliva in the digestion of food?
Answer:
Role of saliva

• Saliva lubricates the food and facilitates mastication.
• Saliva binds the food molecules together.
• Saliva contains ptyalin (salivary amylase) enzyme which acts on starch, glycogen and other carbohydrates to form maltose.

Question 7.
What are the necessary conditions for autotrophic nutrition and what are its byproducts?
Answer:
Photosynthesis is essential in case of autotrophic nutrition

Conditions required for photosynthesis

• CO₂ is necessary for photosynthesis.
• Water is required.
• Sunlight is necessary for photosynthesis.
• Chlorophyll is essential for photosynthesis.
• By-products. Molecular oxygen is liberated as a byproduct.

Question 8.
What are the differences between aerobic respiration and anaerobic respiration? Name some organisms that use anaerobic mode of respiration.
Answer:
(a) Differences between aerobic and anaerobic respiration

Aerobic respiration	Anaerobic respiration
1. It takes place in the presence of oxygen.	1. It takes place in the absence of oxygen.
2. It is completed in cytoplasm and mitochondria of cells.	2. It is completed in the cytoplasm only.
3. It involves the complete oxidation of glucose into CO2 and H2O and a large amount of energy is released.	3. It involves the incomplete oxidation of glucose into CO2 and alcohol or lactic acid and less amount of energy is released.
4. The process is harmless.	4. It is toxic to plants.

(b) Anaerobic respiration takes place in bacteria and yeast.

Question 9.
How are alveoli designed to maximise the exchange of gases?
Answer:

Question 10.
What would be the consequences of a deficiency of haemoglobin in our bodies?
Answer:
Haemoglobin is a respiratory pigment present in RBC of blood. It has high affinity for oxygen. One molecule of haemoglobin carries 4 molecules of oxygen. If simple diffusion were to move oxygen in our body, it is estimated that it would take 3 years for a molecule of oxygen to reach tip of toes from lungs.

Question 11.
Describe double circulation in human beings. Why is it necessary?
Answer:
Double circulation. In human beings heart is four-chambered, having right and left auricles and right and left ventricles. The right auricle receives the deoxygenated blood from the body and sends it into the right ventricle that pumps it to the lungs via a pulmonary arch for oxygenation. The left auricle receives oxygenated blood from the lungs and sends it into the left ventricle, which pumps it to the body through a single aortic arch.

Significance:

• Thus, the deoxygenated and oxygenated blood remain fully separate, and there is complete double circulation.
• It increases efficiency.

Double circulation of blood in birds and mammals.

Question 12.
What are the differences between the transport of materials in xylem and phloem?
Answer:
Differences between transport in xylem and phloem

Transport in xylem	Transport in phloem
1. Water and minerals are transported through xylem.	1. Sucrose, amino acids and other substances are transported through phloem.
2. Xylem helps in upward movement, i.e. from roots to stem, branches and leaves.	2. Phloem is responsible for downward and lateral movement from leaves to other parts.

Question 13.
Compare the functioning of alveoli in the lungs and nephrons in the kidneys with respect to their structure and functioning.
Answer:

• Alveoli of lungs remove CO₂ as a waste during exchange of gases and nephrons filter wastes from blood.
• Alveoli are supplied with extensive network of blood capillaries for gaseous exchange. Bowman’s capsule surrounds a cluster of capillaries for filtration.
• Both increases surface area either for gaseous exchange or filtration.
• Urea and uric acid wastes are removed in the nephron.
• Both purify blood lungs alveoli by removing waste gases and nephrons by filtering the waste products in the form of urine.

Science Guide for Class 10 PSEB Life Processes InText Questions and Answers

Question 1.
Why is diffusion insufficient to meet the energy requirements of multicellular organisms like humans?
Answer:
In multicellular organisms, all the cells of body may not be in direct contact with the surrounding source of oxygen i.e. environment, thus simple diffusion will not meet the oxygen requirements of all the cells. These organisms require specialised organs to meet the oxygen requirement.

Question 2.
What criteria do we use to decide whether something is alive?
Answer:
Features of living organisms

• Movements
• Growth
• Metabolism
• Cellular body
• Nutrition
• Respiration
• Transportation
• Excretion
• Respond to stimuli
• Reproduction.

Question 3.
What are outside raw materials used by living organism?
Answer:
Outside raw materials used by living organism

• Energy obtained from food.
• Oxygen: Required for breaking down of carbon based molecules to liberate energy in the body.
• Water: It is required for proper digestion of food and other functions in the body. It is raw material for photosynthesis in plants. All reactions occur in solution form in the body.
• CO₂ Raw material for photosynthesis in plants. All reactions occur in solution form in the body.

Question 4.
What processes would you consider essential for maintaining life?
Answer:

• Nutrition
• Respiration
• Transportation
• Excretion.

Question 5.
What are the differences between autotrophic and heterotrophic nutrition?
Answer:
Differences between Autotrophic and Heterotrophic nutrition

Autotrophic Nutrition	Heterotrophic Nutrition
1. It occurs in green plants and blue green algae.	1. It occurs in animals and insectivorous plants.
2. CO2 and water are raw materials which combine to form organic compound.	2. They depend on plants and herbivore for their food.
3. They need chlorophyll and sunlight	3. There is no need of chlorophyll and sunlight,

Question 6.
Where do the plants get each of raw materials required for photosynthesis? (PB. Board 2011)
Answer:
Raw materials of photosynthesis

• CO₂
• Water.
• Nitrogen

1. CO₂ is obtained from air. It enters the leaf through stomatal openings.
2. Water is obtained from soil. It enters the leaf through the mid-rib and vein from the root which absorbs it from the soil.
3. Nitrogen: It is obtained from soil.

Question 7.
What is the role of acid in our stomach?
Answer:
HCl is obtained from gastric glands present in the wall of the stomach.

Functions of HCl:

• It provides acidic medium. It is required for the action of enzymes. It changes the pH of food from almost neutral to acidic medium (from pH 7 to 2)
• Activates the inactive proenzyme propepsin into active pepsin.
• Kills the bacteria present in food.
• It softens calcium.
• It regulates the opening and closing of the pyloric aperture.

Question 8.
What is the function of digestive enzymes?
Answer:
Role of digestive enzymes: These enzymes convert the complex non-diffusible form of food into simple diffusible form.

• Ptyalin converts starch into maltose.
• Pepsin breaks down proteins into peptides and amino acids.
• Rennin curdles milk protiens so that they can stay for longer period to be acted upon by pepsin.
• Lipase acts on fats and forms fatty acid and glycerol.
• Maltase acts on maltose and forms glucose.

Question 9.
How is small intestine designed to absorb digested food?
Answer:
Small intestine is a long tubular structure. The inner wall of small intestine is thrown into folds called villi. The absorptive cells have numerous finger-like processes called microvilli. They increase the surface area for absorption of food. These villi have blood vessels named lacteals from absorption of food.

Question 10.
What advantage over an aquatic organism does a terrestrial organism have with regard to obtaining oxygen for respiration?
Answer:
The amount of oxygen dissolved in water is very low as compared to the amount of oxygen in air. Thus these organisms have to make less efforts to obtain oxygen.

Question 11.
What are the different ways in which glucose is oxidised to provide energy in various organisms?
Answer:
Different pathways to provide energy from glucose

Question 12.
How is oxygen and CO₂ transported in human beings?
Answer:
1. Transport of oxygen: It is transported from respiratory organs to body cells,
1. Haemoglobin helps in the transport of oxygen. In the alveoli of the lungs, the haemoglobin (Hb) present in red blood corpuscles combines with oxygen to form oxyhaemoglobin. When the blood reaches the tissue, oxygen is released from the oxyhaemoglobin for the consumption by the tissues.
Hb + O₂ → HbO₂

2. Some of O₂ is transported in the solution form by plasma of blood.

2. Transport of CO₂

• CO₂ diffuses into blood plasma to form physical solution.
• CO₂ forms unstable carbonic acid with water and is transported as such.
• CO₂ is also transported from tissue to lungs as bicarbonates.

Question 13.
How are lungs designed in human beings to maximise the area for exchange of gases?
Answer:
Within the lungs, the primary bronchi divides into smaller and smaller tubes which finally terminate into balloon-like structures called alveoli. These alveoli increase the surface area for exchange of gases. There are 750 million alveoli in the lungs of man. If the alveolar surface is spread out it would cover about 80 m2. Thus it makes efficient exchange of gases.

Each alveolus or air sac has a diameter of 75 to 300 microns and has a very thin wall. The walls of the alveoli are elastic and are supplied with capillaries. Through these thin walls gases are exchanged between the capillaries and the air sacs.

Question 14.
What are the components of the transport system in human beings? What are the functions of these components?
Answer:
There are two main transport systems in human beings :

1. Blood vascular system.
2. Lymphatic system.

Components of blood vascular system

• Blood: It is a reddish viscous fluid connective tissue. In an adult human being, it is 5-6 litres in amount. Blood consists of two parts – plasma and formed elements. (RBCs, WBCs and blood platelets). Blood transports digested food, oxygen, carbon dioxide, nitrogenous wastes and hormones in the body.
• Heart: It is a hollow, muscular pumping organ. The heart sends the blood to lungs. Heart pumps the blood in the body.
• Blood vessels: The blood vessels which carry oxygenated blood are called arteries. They divide to form capillaries of finer dimensions. Exchange of materials takes place across the capillaries. It is possible because the walls of capillaries are extremely thin. The blood from the tissues is returned by veins.

Components of Lymphatic system

1. Lymph: It acts as middle man between blood and tissue. It destroys harmful bacteria
2. Lymph vessels
3. Lymph capillaries
4. Lymph nodes

Question 15.
Why is it necessary to separate oxygenated and deoxygenated blood in mammals and birds?
Answer:

• In the heart of these organisms the left side has oxygenated blood and right side deoxygenated blood.
• The separation of blood allows a highly efficient supply of oxygen to the body.
• It is essential for such animals which have high energy needs.
• They also constantly use energy for maintaining body heat.

Question 16.
What are the components of transport system in highly organised plants?
Answer:
Components of transport system in plants

• Xylem tissue. Vessels and tracheids of roots, stems and leaves are concerned with transport of water and minerals in plants.
• Phloem consists of sieve tubes and companion cells. It transports food, amino acid, phytohormones and other substances from leaves to various parts of plants.

Question 17.
How are water and minerals transported in plants?
Answer:
Transport of water and minerals
1. In xylem tissue, vessels and tracheids of the roots, stems and leaves are interconnected to form a continuous system of water conducting channels reaching all parts of the plants.

2. Plants absorb water and minerals through their entire surface i.e., roots, stem and leaves. However, mainly the water is absorbed by roots from soil.

3. The area of young roots where most of the absorption takes place is the root hair zone.

4. This zone is the area of greatest permeability.

5. Passage of water in root or pathway of water in root

• The entry of water into the root hair dilutes the cell sap. Thus water molecules in root hair increase as compared to adjacent cortical cells.
• Water reaches the passage cells of endodermis. These passage cells lie opposite the xylem.
• They allow water to entre the pericycle.
• So, water enters the xylem from pericycle for upward movement of sap.

6. The Ascent of Sap:
The upward movement of water from the root towards the top of the plant in the xylem vessels is called ascent of sap. The upward transport of water and minerals in plants which are in some cases as tall as 400 ft. poses a serious problem.

7. Transpiration also helps in the absorption and upward movement of water and minerals dissolved in it from roots to the leaves.

Question 18.
How is food transported in plants?
Answer:
Transport of food in plants:
The food prepared in the green leaves of plants is transported through phloem in the form of sucrose solution to storage organs of roots, seeds and fruits. This process is called translocation. This process requires energy. It is provided by ATP molecules. This increases the osmotic pressure in the tissue causing water to move into it. This pressure moves the material in the phloem to tissues which have less pressure.

Question 19.
Describe the structure and functioning of nephron.
Or
How does urine formation occur in human?
Answer:
Structure of a Nephron:
A nephron is made up of:

• a globular double-walled Bowman’s capsule around a clump of capillaries or glomerulus, and
• a tubule surrounded by blood capillaries.

The tubule consists of
(a) a proximal convoluted portion
(b) the loop of Henle, with descending and ascending limbs, and
(c) a distal convoluted part.

The nephron empties into a collecting duct. The two million nephrons of a human being, end to end would extend for nearly 80 km. All the collecting ducts discharge into a central cavity of the kidney (pelvis) that connects to the ureter.

Functioning of Nephron
Urine is formed by 3 processes: glomerular filtration, tubular reabsorption and tubular secretion in the nephrons of the kidney.
1. Ultrafiltration (Glomerular filtration):
Blood is filtered under pressure in the glomeruli present in the cup-like structure of Bowman’s capsule. Glomerular (nephric) filtrate is formed.

Nephron and its function

2. Tubular reabsorption:
In the PCT, entire glucose, amino acids, vitamins and hormones, most of the inorganic ions are reabsorbed by active transport, most of water by osmosis, and some urea by back diffusion from nephric filtrate.
Loop of Henle mainly concentrates urine to conserve water. Here, some inorganic ions are actively taken up and some water leaves by osmosis.

3. Tubular secretion:
In the DCT, collecting tubule and collecting duct, many ions, water (depending upon availability) are secreted in to DCT and collecting duct.
Urine formed passes into bladder from kidney through ureters.

Question 20.
What are the methods used by plants to get rid of excretory products?
Answer:
Excretory products of plants include CO₂, salts, resins, tanins latex etc. Excretion in Plants

• Excess of water passes out during transpiration.
• Plants get rid of dead tissue as a measure to eliminate waste.
• Waste products may be stored in cellular vacuoles.
• Waste products may be stored in leaves which fall off.
• Resins and gums are stored in old xylem.
• Plants also excrete wastes into soil.
• Aquatic plants lose their waste products by diffusion into the water.

Question 21.
How is the amount of urine produced regulated?
Answer:

• Amount of urine formed depends upon the availability of water in the body.
• ADH (Antidiuretic Hormone) regulate the amount of water.
• Osmoregulation helps in regulation of salts and water.
• Urine is stored in urinary bladder.