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This PSEB 7th Class Social Science Notes Chapter 6 Human Environment – Settlements, Means of Transport and Communication will help you in revision during exams.

PSEB 7th Class Social Science Notes Chapter 6 Human Environment – Settlements, Means of Transport and Communication

→ Man: Man is a dynamic organ of the environment.

→ Agriculture and Industrial Revolution: It has given man a permanent lifestyle.

→ Human life: It appeared on earth only a few million years ago.

→ Nomadic life: For the major part of his life, the man was a hunter, gatherer and led a nomadic life.

→ Technology: Man invented fire, progressed from stone age tools to building shelters, agriculture, clothing, etc.

→ Civilisation: It represented cultural development and a stage of life of living in cities.

→ Settlements: Development of permanent villages, towns, and cities.

→ Sites for settlements: Preference-based on the availability of water called Wet Point’ settlements.

→ Other influencing factors: topography, availability of transport and communication, commercial activities.

→ Global village: As the distances have become shorter the world has become a global village.

→ Importance of Transport: Roads, Railway, Air, Shipping, Pipelines.

→ Roads: Offer ‘door-to-door’ service, can be constructed in mountainous regions.

→ Railways: Starting with steam engines, today use diesel or electricity – Metro rail (underground) in cities.

→ Shipping: Cheapest means today’s mechanized boats, trawlers, and ships in use.

→ Air transport: Fast but costly.

→ Pipelines: Used for distribution of oil, gas, or electricity.

→ Communication: Radio, telephone, television, newspapers, internet-global access even sitting in any corner of the earth-information and knowledge-based communication today.

→ Mass communication: Radio, T.V., and newspapers are effective means of mass communication.

→ Temporary settlement: A type of settlement that is occupied for a short time is called a temporary settlement.

→ Permanent settlement: A type of settlement in which people build homes to live permanently.

→ Transport: The means by which people and goods are being carried from one place to another.

→ Roadways: The widely used means of transport for short-distance journeys are roads. The roads can be metalled and unmetalled.

→ Railways: The railways are used to transport heavy and bulky goods long-distance.

→ Waterways: The use of rivers, canals, seas, and oceans to carry goods and passengers through ships and vessels are called waterways.

This PSEB 7th Class Social Science Notes Chapter 5 Natural Vegetation and Wildlife will help you in revision during exams.

PSEB 7th Class Social Science Notes Chapter 5 Natural Vegetation and Wildlife

→ Natural Vegetation: Natural vegetation means the flora which takes seed on its own.

→ Because of differences in surface and climate, many types of vegetation are found on earth.

→ Parts of Natural Vegetation: It can be divided into three parts:

• Forests
• Grazing fields
• Desert bushes

→ Types of Forests: The annual rainfall, climate change, and temperature affect the different types of forests.

→ The forests have been divided into three types:

• Equatorial forests
• Monsoon or deciduous forests
• Coniferous forests

→ Hot Deserts: These places lack rainfall and vegetation and there is sand and sand on all sides.

→ Cold Deserts: In these areas, there is snow everywhere. When the snow melts sometimes, some flowery plants grow.

→ Animal Kingdom: In the world, there are many species of animals. Many colourful birds are also found.

→ Many species of wildlife have become extinct because of human activities.

→ Animal Sanctuaries: For the protection of wildlife many sanctuaries have been made so that the wildlife can be saved from extinction.

→ Forests: A tract of woodland or a type of biome in which the dominant plants are trees.

→ Grasslands: The areas of the world where natural vegetation is made up of grass.

→ Tropical Evergreen: The forests of areas with an annual rainfall of 200 cm or more.

→ Tropical Deciduous Forests: These forests are the typical type of natural vegetation of monsoon regions.

→ Mediterranean Forests: These forests are found in areas with hot summers and mild rainy winters.

→ Thorny bushes: These are the typical vegetation of dry deserts. Xerophytic vegetation grows with long roots.

→ Tundra Vegetation: The vegetation of extremely cold regions consists of mosses and lichens.

→ Coniferous Forests: These are also called Taiga. Trees are tall, softwood, and have a conical shape with needle-like leaves.

This PSEB 7th Class Social Science Notes Chapter 4 Ocean will help you in revision during exams.

PSEB 7th Class Social Science Notes Chapter 4 Ocean

→ Oceans: The big reservoirs of water on earth are known as oceans. The Pacific Ocean, Atlantic Ocean, and Indian ocean are the main oceans.

→ Pacific Ocean: It is the longest and deepest ocean on earth. It is so deep that even the highest peak Mt. Everest can sink in it.

→ Seas: Every ocean is divided into small parts. These small parts are known as seas.

→ Speeds of Ocean Water: The ocean water has three speeds waves, currents, tides.

→ Waves: Ripples in ocean water caused by winds blowing over the sea.

→ Current: When the ocean water starts moving in a specific direction it is known as oceanic current.

→ The speed of oceanic current normally ranges from 2 km/hr to 10 km/hr.

→ Tides: Regular rise and fall of ocean water as a result of the gravitational pull of the sun and the moon. It happens twice in 24 hrs.

→ High tide and Low tide: On a full moon day the tides of the sea rise to the highest level. It is called high tides.

→ When the oceanic tides rise to the lowest level it is called low tides.

→ Water cycle: Unending movement of water between hydrosphere, atmosphere, lithosphere, and back to the hydrosphere.

→ Groundwater: Water that soaks underground, roots of plants help water go underground.

→ Transpiration: Water vapours are returned to the atmosphere by plants.

→ Water budget: The balancing of precipitation on the ground with evaporation and transpiration in the atmosphere.

→ Waves: Ripples in ocean water caused by winds blowing over the sea.

This PSEB 7th Class Social Science Notes Chapter 3 Atmosphere and Temperature will help you in revision during exams.

PSEB 7th Class Social Science Notes Chapter 3 Atmosphere and Temperature

→ Atmosphere: The big protective layer surrounding the earth.

→ Composition of Atmosphere: Atmosphere is a mixture of different gases. Two gases are main Nitrogen (almost 78%) and Oxygen (almost 21%).

→ Layers of Atmosphere: Four layers.

• Troposphere
• Stratosphere
• Mesosphere
• Thermosphere

→ Troposphere: This layer is the closest to the earth. All the happenings take place in the troposphere. This layer protects us from the dangerous ultra-violet rays of the sun.

→ Factors affecting the atmosphere: Three main factors affect the atmosphere

• Latitudes
• Height above the sea level
• Distance from the sea.

→ Global Warming: The increase in global temperatures brought about the increased emission of greenhouse gases into the atmosphere.

→ Troposphere: It is the lowermost layer of the atmosphere.

→ Weather: It is the description of the atmospheric conditions of a particular place at a particular time for a short period of time.

→ Climate: It is the composite or integrated picture of the weather conditions over a long period of time such as a season or a year.

This PSEB 7th Class Social Science Notes Chapter 2 The Internal and External Face of the Earth will help you in revision during exams.

PSEB 7th Class Social Science Notes Chapter 2 The Internal and External Face of the Earth

→ Lithosphere: It includes the earth’s crust called Sial. The normal width of this part is almost 100 kms. It has more Silicon and Aluminium.

→ Minerals: These are those natural substances that are made up of one element or a combination of elements.

→ Rocks: The combined form of natural minerals is called Rocks. These are of three types Igneous, Sedimentary and Metamorphic.

→ Magma: In the depth of the earth, most substances are found in a melt state called Magma.

→ Lava: When magma reaches the earth’s surface, it is called lava.

→ Igneous and Metamorphic Rocks:

• The molten lava cools down, gets solidified, and thus comes into existence-Igneous Rocks.
• Metamorphic rocks come into existence through Igneous and Sedimentary rocks.
• In fact, Igneous and sedimentary rocks undergo a transformation that is chemical as well as structural because of pressure and heat.
• As a result, the construction and structure of these rocks changes, and these are called Metamorphic rocks.
• Example: Granite is an igneous rock while Gneiss made up of Granite is a metamorphosized rock.

→ Metallic and Non-metallic Minerals: Metallic minerals contain metals like iron, silver, etc. while Non-metallic minerals don’t contain metals like Abhrak, Potassium, Gypsum, etc.

→ Preservation of Minerals: It takes hundreds of years the make minerals, so these must be preserved.

→ Crust: The outermost layer of earth.

→ Core: The innermost layer of the earth.

→ Sedimentary rocks: Any rock formed by the deposition of sediments.

→ Mantle: The mantle is the intermediate layer between the crust and the core of the earth.

→ Minerals: A mineral is a naturally occurring substance having a definite chemical composition and physical properties.

→ Lithospheric plates: A large segment of earth crust that can ‘float’ across the heavier, semi-molten rock below.

This PSEB 7th Class Social Science Notes Chapter 1 Environment will help you in revision during exams.

PSEB 7th Class Social Science Notes Chapter 1 Environment

→ Earth: The earth is called a blue planet – 71% is water and 29% is an island.

→ Environment: Environment means surroundings. Its components are the Physical, Biological, and Cultural environment.

→ Physical Environment: The prevailing natural conditions comprising the land, water, and air.

→ Biological Environment: It consists of all life forms – animals including humans, plants, and other organisms.

→ Earth’s Spheres: The above four components form spheres called the lithosphere, hydrosphere, atmosphere, and biosphere.

→ Lithosphere: The outermost layer of the crust is called the lithosphere (Rock-sphere).

→ The rocky layer under continents is called Sial and under oceans is called Sima.

→ Hydrosphere: Rivers, lakes, seas, and oceans comprise this sphere and provide support to all life forms.

→ Atmosphere: The thin layer of air around earth.

→ Biosphere: Biosphere is a narrow zone of contact between land, water, and air. It is a life-giving sphere.

→ Biotic environment: The world of living things.

→ Abiotic environment: The world of non-living things.

→ Components of the environment: Land, Water, Air.

→ Crust: Hardtop layer of the earth.

→ Landforms: Mountains, Plateaus, Plains.

→ Ecosystem: A community of plants and animals within a particular physical environment.

→ Human Environment: Human life is closely related to the environment of the earth.

This PSEB 7th Class Science Notes Chapter 18 Wastewater Story will help you in revision during exams.

PSEB 7th Class Science Notes Chapter 18 Wastewater Story

→ Sewage is liquid waste, most of it is water that has dissolved and suspended impurities. These impurities are called contaminants.

→ An underground network of pipes that carry wastewater from a home to a point of disposal is called Sewerage.

→ Sewage is transported through the closed pipes to the wastewater treatment plants where pollutants are separated and reformed and then flow into rivers and oceans.

→ During wastewater treatment pollutants are separated by physical, chemical, and biological methods.

→ Sludge is a solid that settles to the bottom during water purification.

→ Wastewater treatment co-products are sludge and biogas.

→ A manhole is a lid-covered open space through which a person can enter and can check the sewerage system.

→ Open defecation is a breeding ground for flies, mosquitoes, and other insects that cause many diseases.

→ Do not throw oil, ghee, grease, etc. in a drain or in the open. Doing so will make drain chock.

→ Throw trash only in the bin (dustbin).

→ Pollutants: Dissolved and suspended impurities in dirty water are called pollutants.

→ Sewerage: A network of small and large pipes that carry wastewater to the drainage area.

→ Manhole: Large open mouth holes are made at every 50-60 meters of the sewerage system.

→ Individual who enters the sewage can check and remove sewage problem if any.

→ Water Treatment Plant: A place where impurities are separated from wastewater.

→ Water Treatment: The process of separating impurities from wastewater is called water treatment.

→ Sludge is the solid that settles in the sewage water purification tank.

→ Septic tank: This is a small system of sewage treatment containing monoaerobic bacteria that remove waste products. It has connections with main sewage pipes.

This PSEB 7th Class Science Notes Chapter 17 Forests: Our Lifeline will help you in revision during exams.

PSEB 7th Class Science Notes Chapter 17 Forests: Our Lifeline

→ A system made up of plants, animals, and micro-organisms are called a forest.

→ The top layer of the forest is Canopy Layer, the mid-layer is the Crown layer and the lower layer is the Understory layer.

→ Forests protect the soil from erosion.

→ Soil helps in the growth and development of trees.

→ Humus shows that nutrients from the bodies of dead plants and animals have been incorporated into the soil.

→ Forests act like green lungs and produce many products. That is why forests are so important.

→ A forest is an area whose uppermost layer is topped by trees.

→ Forests are always green.

→ A variety of animals, plants, and insects are found in forests.

→ All wild animals, herbivores or carnivores, depend on plants for food in one or the another way.

→ Forests continue to grow and develop and can regenerate.

→ Forests affect climate, water cycle, and air quality.

→ Trees, shrubs, vegetation, herbs, etc. all are found in forests.

→ According to the height of trees and plants, forests are divided into three categories:

• Canopy
• Crown
• Understory

→ Forest soil helps in regeneration.

→ Forest plants emit vapours and help bring rain and regulate the temperature of the environment.

→ Different layers of vegetation in forests provide food and shelter to animals, birds, and insects.

→ In the forest, soil, water, air, and living things have interdependence on each other.

→ Forests provide important basic necessities for communities living in forested areas.

→ Forests maintain and regulate climate, water cycle, and air quality.

→ Decomposers depend on the dead bodies of plants and animals and turn them into simple substances.

→ Deforestation causes global warming, decreases rainfall, increases pollution, and erodes soil.

→ To maintain balance in nature and maintain habitat for wild animals and plants forest plays an important role.

→ Forest: A forest is an area where there is a lot of dense vegetation, including animals, trees, bushes, and weeds that grow naturally.

→ Canopy: The top layer of tree branches forms a dense top layer of trees on earth which is called the canopy.

→ Crown layer: The layer in which the branches and trunks of trees come, is called the crown or crown layer.

→ Understory Layer: The shaded area below which there is very little light, is called the lower or understory layer.

→ Ecosystems: Living things and their environment work together to create ecosystems. Plants, animals, and microorganisms are the biological components of the ecosystem. These are divided into different categories of producers, consumers, and decomposers.

→ Food chain: In ecology, the sequence of transfer of matter and energy in the form of food from one organism to another organism is called a food chain.
For example:

→ Food Web: A food web consists of a network of many food chains. A food chain helps provide food to organisms at the next food level.

→ Afforestation: The process of planting trees on a large scale is called Afforestation.

→ Decomposers: Microorganisms that decompose the dead bodies of plants and animals into humus, are called Decomposers.

→ Erosion: In the absence of trees and plants top layer of soil is lost, This process of carrying away the topsoil by wind and water is called soil erosion.

→ Replenishment of forest: Planting a large number of plants and trees in the forest area is called forest replenishment.