Important Questions for Class 8 Science Chapter 12

If you are preparing for your Class 8 Science examination, practising important questions is one of the easiest ways to revise the chapter quickly. Chapter 12, How Nature Works in Harmony, helps you understand how living organisms and non-living components work together to maintain balance in nature. In this chapter, you learn about ecosystems, habitats, food chains, food webs, biodiversity, decomposers, and the impact of human activities on the environment.

The Important Questions for Class 8 Science Chapter 12 given below cover the important concepts that are commonly asked in school examinations. By solving these MCQs, assertion-reason questions, short answer questions, and long answer questions, you can improve your understanding of the chapter and revise effectively. If you are looking for the How Nature Works in Harmony PDF, you can also use these questions for quick revision before your exam.

Important Questions for Class 8 Science Chapter 12  

Practise the following Important Questions for Class 8 Science Chapter 12 to revise ecosystems, habitats, biodiversity, food chains, food webs, and the relationship between living and non-living components. These questions are designed to help you prepare confidently for your school examinations. 

Q1. Which of the following is an example of an abiotic component of an ecosystem?

(A) Sunlight

(B) Water

(C) Soil

(D) All of the above

Q2. Match the correct pair (Abiotic factors with examples):

(A) 1→b, 2→d, 3→c, 4→a

(B) 1→a, 2→c, 3→b, 4→d

(C) 1→c, 2→a, 3→d, 4→b

(D) 1→d, 2→b, 3→a, 4→c

Q3. Assertion: The destruction of forests leads to loss of biodiversity.
Reason: Forests provide food and habitat for many species of flora and fauna.

(A) Both correct, Reason explains Assertion

(B) Both correct, Reason doesn't explain Assertion

(C) Assertion correct, Reason incorrect

(D) Assertion incorrect, Reason correct

Q4. If we completely remove the decomposers from an ecosystem, the ecosystem functioning will be adversely affected because—

(A) Energy flow will be blocked

(B) Rate of decomposition of other components will be very high

(C) Herbivores will not receive solar energy

(D) Mineral movement will be blocked

Q5. Among the following, choose the incorrect statement about biomagnification:

(A) DDT accumulates in food chains

(B) Top carnivores have maximum concentration

(C) It affects aquatic food chains

(D) Chemicals are easily broken down by bacteria

Q6. Assertion: Energy flow in a food chain is unidirectional.
Reason: Energy lost as heat at one trophic level cannot be used by the next.

(A) Both true, Reason explains Assertion

(B) Both true, Reason doesn't explain Assertion

(C) Assertion true, Reason false

(D) Assertion false, Reason true

Q7. Which interaction involves one organism capturing and consuming another organism?

(A) Commensalism

(B) Mutualism

(C) Parasitism

(D) Predation

Q8. Which statement is correct about terrestrial and aquatic habitats?

(A) Both contain only non-living components

(B) Both support life adjusted to their specific conditions

(C) Only terrestrial habitats have producers

(D) Aquatic habitats do not contain consumers

Q9. Which of these pairs correctly matches a habitat with its main component feature?

(A) Pond – stagnant water

(B) Desert – high rainfall

(C) Grassland – absence of plants

(D) Polar region – hot summers

Q10. Demoiselle Cranes are seen in Khichan, Rajasthan, during which season?

(A) Summer

(B) Winter

(C) Monsoon

(D) Spring

Q11. Why do migratory birds travel thousands of miles to India?

(A) To build permanent nests in forests

(B) To avoid harsh climates and search for food

(C) To escape predators in their native regions

(D) To grow crops with farmers

Q12. A river flowing through farmland and grassland shows interaction between which types of ecosystems?

(A) Terrestrial and aquatic

(B) Desert and mountain

(C) Urban and terrestrial

(D) Grassland and desert

Q13. What is a food chain? Give one example from a terrestrial ecosystem.

Q14. State three ways in which human activities disturb ecosystems.

Q15. What are biotic components and abiotic components of an ecosystem? Give one example of each.

Q16. (a) Define a food web. (b) State one significance of a food web in an ecosystem.

Q17. Differentiate among primary, secondary, and tertiary consumers with examples.

Q18. What is meant by interdependence between organisms? Explain the types of interdependence with one example each.

Q19. A study compared two ponds — Pond A with fish and many flowering plants around it, and Pond B without fish and fewer flowering plants. Explain how the presence of fish in a pond can affect seed production in nearby plants. Also state what this study shows about interactions in an ecosystem.

Q20. How do healthy ecosystems support farming, and why are modern chemical-intensive farming practices considered unsustainable? Explain with suitable points.

How Nature Works in Harmony MIQs PDF

If you are looking for the How Nature Works in Harmony MIQs PDF, these important questions are useful for quick revision before your examination. They cover the key concepts from the chapter, including ecosystems, biodiversity, food chains, food webs, habitats, and environmental conservation, helping you revise the complete chapter in less time. 

Download How Nature Works in Harmony PDF

The Important Questions for Class 8 Science Chapter 12 help you revise all the important concepts covered in How Nature Works in Harmony. By practising these questions regularly, you can strengthen your understanding of ecosystems, food chains, biodiversity, habitats, and the role of living and non-living components in nature. Make sure you understand each concept before memorising the answers, as this will help you perform better in your school examinations.