Energy Flow in an Ecosystem
Q1. What is an ecosystem?
A. An ecosystem is a community of living organisms interacting with each other and with their non-living environment.
Q2. Give two examples of natural ecosystems.
A. Forest, Pond.
Q3. Give two examples of artificial ecosystems.
A. Aquarium, Crop field.
Q4. What is the main source of energy for an ecosystem?
A. The Sun.
Q5. Define trophic level.
A. Each step in the food chain where energy is transferred is called a trophic level.
Q6. Name the first trophic level in any food chain.
A. Producers (plants).
Q7. What are primary consumers?
A. Herbivores that feed directly on plants.
Q8. Give an example of a primary consumer.
A. Grasshopper, Cow.
Q9. What are secondary consumers?
A. Carnivores that feed on herbivores.
Q10. Give an example of a secondary consumer.
A. Frog, Sparrow.
Q11. What are tertiary consumers?
A. Top carnivores that feed on secondary consumers.
Q12. Give an example of a tertiary consumer.
A. Tiger, Hawk.
Q13. State the 10% law of energy transfer.
A. Only about 10% of the energy at one trophic level is passed on to the next level.
Q14. Name the scientist who proposed the 10% law.
A. Raymond Lindeman.
Q15. Why is the flow of energy in an ecosystem unidirectional?
A. Because energy cannot be recycled and is lost as heat at each trophic level.
Q16. What is a food chain?
A. The sequence of transfer of energy from one organism to another through feeding relationships.
Q17. Give an example of a food chain in a grassland ecosystem.
A. Grass → Grasshopper → Frog → Snake → Hawk.
Q18. What is a food web?
A. A network of interconnected food chains in an ecosystem.
Q19. Why are food webs more stable than food chains?
A. Because they provide alternative food sources and increase ecosystem stability.
Q20. What are decomposers?
A. Microorganisms like bacteria and fungi that break down dead matter into simpler substances.
Q21. Why are decomposers important?
A. They recycle nutrients back into the soil for use by plants.
Q22. Define biomass.
A. The total mass of living matter at a particular trophic level.
Q23. What is ecological pyramid?
A. A graphical representation of relationships between organisms at different trophic levels.
Q24. Name three types of ecological pyramids.
A. Pyramid of numbers, Pyramid of biomass, Pyramid of energy.
Q25. Which ecological pyramid is always upright?
A. Pyramid of energy.
Q26. Why is the pyramid of energy always upright?
A. Because energy decreases at each trophic level due to loss as heat.
Q27. Give one limitation of the pyramid of numbers.
A. It does not show the exact energy flow between trophic levels.
Q28. What will happen if all producers in an ecosystem are destroyed?
A. The entire food chain will collapse as no energy will be available for consumers.
Q29. Why are there rarely more than four trophic levels in a food chain?
A. Because energy becomes too limited to support higher levels.
Q30. How do human activities affect energy flow in ecosystems?
A. Activities like deforestation, pollution, and overhunting disrupt natural food chains and reduce biodiversity.