Unit-2: Ecosystem and Biodiversity

Question 1

Q1: What are the biotic components of an ecosystem?

Answer 1

A1: Producers, consumers (primary, secondary, tertiary), and decomposers.

Question 2

Q2: What are the abiotic components of an ecosystem?

Answer 2

A2: Sunlight, temperature, water, soil, air, and nutrients.

Question 3

Q3: Define producers and give an example.

Answer 3

A3: Producers are autotrophs that synthesize their food via photosynthesis or chemosynthesis (e.g., plants).

Question 4

Q4: What is the role of decomposers in an ecosystem?

Answer 4

A4: Decomposers break down dead organic matter into simpler substances, recycling nutrients.

Question 5

Q5: What is a food chain? Give an example.

Answer 5

A5: A linear sequence of energy flow through trophic levels. Example: Grass → Grasshopper → Frog → Snake → Eagle.

Question 6

Q6: How is a food web different from a food chain?

Answer 6

A6: A food web shows interconnected food chains with multiple feeding relationships.

Question 7

Q7: What are ecological pyramids? Name their types.

Answer 7

A7: Ecological pyramids represent trophic levels. Types: Pyramid of Numbers, Pyramid of Biomass, Pyramid of Energy.

Question 8

Q8: State the 10% law in energy flow.

Answer 8

A8: Only 10% of energy is transferred to the next trophic level, while 90% is lost as heat.

Question 9

Q9: What is ecological succession?

Answer 9

A9: Gradual changes in the ecosystem’s structure and species over time.

Question 10

Q10: Differentiate between primary and secondary succession.

Answer 10

A10:

Primary Succession: Occurs on bare surfaces without soil.
Secondary Succession: Occurs in areas with pre-existing soil after a disturbance.

Question 11

Q11: What are the main processes of the nitrogen cycle?

Answer 11

A11: Nitrogen fixation, nitrification, assimilation, ammonification, denitrification.

Question 12

Q12: How is carbon cycled in an ecosystem?

Answer 12

A12: Through respiration, photosynthesis, decomposition, and burning of fossil fuels.

Question 13

Q13: What is the significance of the phosphorus cycle?

Answer 13

A13: It cycles phosphorus, a vital nutrient for DNA, RNA, and ATP, through rocks, plants, animals, and sediments.

Question 14

Q14: What is the main feature of a forest ecosystem?

Answer 14

A14: Dense trees, stratified vegetation, and rich biodiversity.

Question 15

Q15: Name the main functions of a grassland ecosystem.

Answer 15

A15: Grazing for animals, soil conservation, and water retention.

Question 16

Q16: What adaptations are found in desert ecosystems?

Answer 16

A16: Plants store water (succulents), animals conserve water and are active at night (nocturnal behavior).

Question 17

Q17: List the types of aquatic ecosystems.

Answer 17

A17: Freshwater (ponds, lakes, rivers) and marine (oceans, estuaries).

Question 18

Q18: What are the levels of biodiversity?

Answer 18

A18: Genetic diversity, species diversity, and ecosystem diversity.

Question 19

Q19: Define genetic diversity.

Answer 19

A19: The variety of genes within a species.

Question 20

Q20: What is biogeographical classification?

Answer 20

A20: Division of a region based on its geography and biodiversity.

Question 21

Q21: Name a few biogeographical zones of India.

Answer 21

A21: Himalayas, Western Ghats, Thar Desert, Sundarbans.

Question 22

Q22: Why is biodiversity important for aesthetic value?

Answer 22

A22: It adds beauty and provides recreational opportunities.

Question 23

Q23: Why is India called a mega-diversity nation?

Answer 23

A23: India has 7% of the world’s species and diverse ecosystems due to its varied climate and topography.

Question 24

Q24: Name the biodiversity hotspots in India.

Answer 24

A24: Western Ghats, Himalayas, Indo-Burma region, Sundaland (Nicobar Islands).

Question 25

Q25: What are the major threats to biodiversity?

Answer 25

A25: Habitat loss, poaching, and man-wildlife conflicts.

Question 26

Q26: How does poaching affect biodiversity?

Answer 26

A26: It leads to the decline or extinction of species.

Question 27

Q27: What is in-situ conservation? Give examples.

Answer 27

A27: Conservation within natural habitats. Examples: National parks, wildlife sanctuaries, biosphere reserves.

Question 28

Q28: What is ex-situ conservation? Give examples.

Answer 28

A28: Conservation outside natural habitats. Examples: Zoos, botanical gardens, gene banks.