class 8 history chapter 2lecture ppt.pptx

ppt

1. ENVIRONMENT 5 th june Story of R avi Whatever you see in Your surroundings

2. Is the environment around us changing?

3. TOPICS What is Environment – Components of Environment- Natural Environments- What is Ecosystem- Human Environments-

4. What is ENVIRONMENT

5. Definition of Environment Place people things that surrounded any living organism Environment is the surrounding we live in. It consists of both the biotic and the abiotic components. Our environment includes the mountain, rivers, lakes, animals, plants,people .

6. Components of ENVIRONMENT

7. Components of Enviornment

8. EXAMPLE Plant River Car Parks Air Buildings Water Bridges Land Roads

9. Natural components Def -Natural environment components means land (including soils), subsurface resources, waters, the atmospheric air, flora and fauna  Ex.water air flower plant animal

10. Biotic Components Biotic Components : All the living organisms in our environment are said to be the biotic components. Example: Plants and animals. Abiotic components Abiotic Components : All the non living organisms in the environment form the abiotic components. Example: Land and mountain.

11. Human Components   Human-made component like roads, bridges, industries, etc And finally human component consists of individual, family, society, etc. It is also called as human environment and it reveals the activities, creations, and interactions among human beings.

12. Natural Environment Natural Environment: The natural environment consists of all the things occurring naturally like land, water, plants, air etc.

13. Domains of Natural environment Lithosphere Hydrosphere Atmosphere Biosphere

14. Lithosphere  lithosphere is the rigid, outermost layer of the Earth's rocks and minerals, which consists of the crust and upper mantle . The term "lithosphere" comes from the Greek word  litho , which means "stone," and "sphere," referring to the rough shape of the Earth.

15. Atmosphere An atmosphere contains the air that we breathe and is a blanket of gases that surrounds Earth . It is held near the surface of the planet by Earth’s gravitational attraction. A barometer is used to measure air pressure. Argon, oxygen and nitrogen from the three main constitutions of the atmosphere

16. Hydrosphere The hydrosphere is the combined mass of water found on, under, and above the surface of the earth. This includes water in liquid and frozen forms in groundwater, oceans, lakes and streams . Approximately 75% of Earth’s surface, an area of some 361 million square kilometres , is covered by ocean.

17. Biosphere biosphere is a narrow zone on the surface of the earth where soil, water, and air combine to sustain life. Life can only occur in this zone. From fungi and bacteria to large animals, there are several different types of life. The biosphere is characterized as an area that contains all living organisms and the products of their activities. As a result, it plays a critical role in the maintenance of ecosystems .

18. Lithosphere : The solid crust or the hard top layer of the earth that is made up of rocks and minerals and with a thin layer of soil. Eg : mountains, plateaus, highlands, Hydrosphere : Hydrosphere basically consists of all the water bodies on the surface of the planet earth. This includes the sea, rivers, lakes, etc. Atmosphere : This thin layer or blanket of air that surrounds the earth is known as Atmosphere . This layer protects us from the harmful ultraviolet rays of the sun. This consists of a number of gases, dust and water vapour . Biosphere : The biosphere of the earth includes living organisms present in our environment . All the plants and animals are a part of our biosphere.

19. What is Ecosystem

20. What defines an ecosystem? An ecosystem is a community of living organisms (plants, animals and microbes) in a particular area. The term eco' refers to a part of the world and system' refers to the co- ordinating units . An ecosystem is a community of organisms and their physical environment interacting together

21. Human Environment

22. Human Environment This is a type of environment where the human beings modify their surroundings as per their own requirements. The early human beings lived a very simple life and fulfilled their needs from the natural resources available around them. With time and development human needs started increasing, with this growing needs humans began to change and modify their environment around . For example: The wheel was invented, people started a barter system, trade and commerce started. There were various other developments too that changed the way of living of the humans and they started creating their own environment. We humans must learn the optimum utilisation of resources.

23. What is an ecosystem? All plants, animals and human beings depend on their immediate surroundings. They are also interdependent on each other. This relation between the living organisms as well as the relation between the organism and their surroundings form an ecosystem

24. What do you mean by the natural environment ? The natural environment consists of land, water, air, plants and animals. Thus, the natural environment refers to both biotic (plants and animals) and abiotic (land) conditions that exist on the earth.

25. Which are the major components of the environment ? The major components of the environment are—natural (land, air, water, living things), human-made (buildings, parks, bridges, roads, industries, monuments, etc.), and humans (individual, family, community, religion, educational, economic, etc ).

26. Give four examples of a human-made environment . Four examples of human-made environments—buildings, parks, bridges, and roads.

27. What is the lithosphere? The lithosphere is the solid crust or the hard top layer of the earth. It is made up of rocks and minerals and covered by a thin layer of soil. It is an irregular surface with various landforms such as mountains, plateaus, plains, valleys, etc.

28. Which are the two major components of the biotic environment Plants and animals are the two major components of a biotic environment,

29. What is the biosphere ? The biosphere is a narrow zone of the earth where land, water, and air interact with each other to support life. Thus, plant and animal kingdom together make biosphere, ie ., the living world .

30. Tick the correct answer . Which is not a natural ecosystem? (a) Desert (b) Aquarium (c) Forest. Which is not a component of the human environment? (a) Land (b) Religion (c) Community. Which is a human-made environment? (a) Mountain (b) Sea (c) Road. Which is a threat to the environment? (a) Growing plant              (b) Growing population (c) Growing crops.

31. Match the following: Biosphere       ( a)  blanket of air which surrounds earth Atmosphere       ( b)   domain of water Hydrosphere     ( c)    gravitational force of the earth Environment      (d)    our surroundings ( e) the narrow zone where land, water, and air interact

32. Man modifies his environment Man modifies his environment in the following ways: He cuts forests and clears land for agriculture, industries, and habitation. He tills land for agriculture. He uses the land to build buildings, roads, and railways. He uses water. He uses air for his survival. He sets up industries, factories, etc. He does numerous other activities for his life, making it comfortable

33. Plants and animals depend on each other . Plants and animals depend on each other in the following ways: Plants provide food to animals. They, in the form of forests, provide shelter to wildlife. Wildlife adds beauty to the forests. Animals provide manure to plants for growth. Animals also provide beauty to forests. Dead animals also provide humus content.