Imp Questions For All Chapters – General Science Class 8
Short Questions
1. What is an ecosystem?
- An ecosystem is a place where living (biotic) and non-living (abiotic) things interact.
2. Give two examples of ecosystems.
- Forest, pond, river, ocean, desert.
3. What are the two main types of ecosystems?
- Natural ecosystems (forests, rivers) and man-made ecosystems (farms, gardens).
4. What is a biome?
- A biome is a large ecosystem covering a big area with similar climate and organisms.
5. Give two examples of biomes.
- Rainforest and grasslands.
6. What are abiotic factors?
- Non-living things in an ecosystem, like air, water, soil, and sunlight.
7. What are biotic factors?
- Living things in an ecosystem, like plants, animals, and microbes.
8. What are producers in an ecosystem?
- Plants, because they make their own food through photosynthesis.
9. What are consumers in an ecosystem?
- Animals, because they depend on plants or other animals for food.
10. What are decomposers?
- Organisms like bacteria and fungi that break down dead plants and animals.
11. What is a food chain?
- A sequence of who eats whom in an ecosystem, showing energy flow.
12. What is a food web?
- A food web is a network of many interconnected food chains in an ecosystem.
13. What is deforestation?
- The cutting down of large areas of trees and forests.
14. How does deforestation harm ecosystems?
- It destroys animal habitats, reduces oxygen, and causes soil erosion.
15. Why are large dams harmful to ecosystems?
- Dams submerge forests and grasslands, affecting wildlife and water flow.
16. What is urbanization?
- The growth of cities and towns, which leads to destruction of natural ecosystems.
17. Why was the rhinoceros restored in Dudhwa National Park?
- It became extinct due to hunting, so rhinos were bred and reintroduced in 1984.
18. Give two examples of aquatic ecosystems.
- Ponds and oceans.
19. What is an example of a desert ecosystem?
- Thar Desert in India.
20. How can we protect ecosystems?
- By planting trees, reducing pollution, and protecting wildlife.
Long Questions
1. What is the difference between a food chain and a food web?
- A food chain shows a single path of energy transfer from producers to consumers. A food web is made up of many interlinked food chains, showing multiple feeding relationships. A food web is more complex and realistic than a food chain.
2. How does population growth affect ecosystems?
- More people need more food, water, and land, leading to deforestation and pollution. Overuse of resources destroys natural habitats and reduces biodiversity. It also causes waste accumulation and climate change, harming ecosystems.
3. How does urbanization destroy ecosystems?
- Urbanization removes forests, grasslands, and wetlands to build cities, roads, and industries. This leads to air and water pollution, making survival difficult for many species. It also reduces oxygen levels, increases waste, and harms biodiversity.
4. Why are decomposers important in an ecosystem?
- Decomposers like bacteria and fungi break down dead plants and animals into nutrients. These nutrients return to the soil, helping plants grow and keeping the ecosystem balanced. Without decomposers, waste would accumulate, and nutrients would not recycle.
5. What are the causes of wars, and how do they affect ecosystems?
- Wars happen due to land disputes, water shortages, and political conflicts. They destroy forests, pollute air and water, and displace animals and people. The use of weapons and bombs damages soil, kills wildlife, and increases pollution.
6. How do abiotic factors affect ecosystems?
- Abiotic factors like sunlight, air, water, and soil help plants grow, producing food and oxygen. These plants support herbivores and carnivores, forming a balanced ecosystem. Without proper abiotic factors, ecosystems cannot survive properly.
7. What is the difference between evergreen forests and grasslands?
- Evergreen forests receive heavy rainfall, so trees stay green throughout the year. Grasslands get less rain, so they have mostly grasses and few trees. Evergreen forests have thick vegetation, while grasslands are open and spread out.
8. Why should we protect ecosystems?
- Ecosystems provide oxygen, food, water, and shelter for all living beings. Protecting them prevents climate change, maintains biodiversity, and keeps nature balanced. If ecosystems are destroyed, humans and animals will suffer from food and resource shortages.
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