CBSE Class 12 Biology Very Short Answer Questions – Biodiversity and Conservation (NCERT Based)

Unit V: Ecology and Environment | Chapter 15: Biodiversity and Conservation

CBSE Class 12 Biology Chapter 15 Very Short Answer Questions – Biodiversity and Conservation (NCERT)

Course & Examination Details

• Course: CBSE Class 12 Biology
• Unit: Unit V – Ecology and Environment
• Chapter: Chapter 15 – Biodiversity and Conservation
• Board: Central Board of Secondary Education (CBSE)
• Syllabus Base: Strictly as per NCERT Textbook
• Exam Use: CBSE Board Exams, School Tests, Quick Revision

Very Short Answer Type Questions (20–30 Words Each)

(Prepared strictly according to NCERT syllabus and CBSE answer-writing standards)

Section A: Biodiversity and Its Levels (Q1–Q10)

Q1. What is biodiversity?
Ans: Biodiversity refers to the total variety of living organisms present on Earth, including plants, animals, and microorganisms at all biological levels.

Q2. Name the three levels of biodiversity.
Ans: Genetic diversity, species diversity, and ecosystem diversity are the three levels of biodiversity.

Q3. What is genetic diversity?
Ans: Genetic diversity refers to variation in genes within a species, enabling adaptation to environmental changes.

Q4. Define species diversity.
Ans: Species diversity refers to the variety and relative abundance of different species present in a particular area.

Q5. What is ecosystem diversity?
Ans: Ecosystem diversity refers to the variety of ecosystems present in a geographical region.

Q6. Which level of biodiversity is highest in tropical rainforests?
Ans: Species diversity is highest in tropical rainforests.

Q7. Why is genetic diversity important?
Ans: Genetic diversity increases adaptability and survival of species during environmental changes.

Q8. Give one example of genetic diversity.
Ans: Different varieties of rice grown in India show genetic diversity.

Q9. Which country is considered mega-diverse?
Ans: India is considered one of the mega-diverse countries.

Q10. What percentage of global species diversity is found in India?
Ans: India harbors nearly 8% of global species diversity.

Section B: Patterns of Biodiversity (Q11–Q18)

Q11. What is latitudinal gradient in biodiversity?
Ans: Biodiversity increases from poles towards the equator, showing maximum diversity in tropical regions.

Q12. Why do tropics show higher biodiversity?
Ans: Tropics have stable climate, high productivity, and longer evolutionary time.

Q13. What is species–area relationship?
Ans: Species richness increases with increasing area according to the relationship S = CAᶻ.

Q14. Who proposed the species–area relationship?
Ans: Alexander von Humboldt proposed the species–area relationship.

Q15. What does ‘Z’ represent in species–area relationship?
Ans: ‘Z’ is the slope of the regression line representing species increase rate.

Q16. On which scale is species–area relationship plotted?
Ans: It is plotted on a logarithmic scale.

Q17. Which regions show steeper species–area slopes?
Ans: Large areas like continents show steeper slopes.

Q18. What is endemism?
Ans: Endemism refers to species restricted to a specific geographical area.

Section C: Importance of Biodiversity (Q19–Q26)

Q19. Why is biodiversity important ecologically?
Ans: Biodiversity maintains ecosystem stability, productivity, and resilience against environmental disturbances.

Q20. Name one ecosystem service provided by biodiversity.
Ans: Pollination is an important ecosystem service.

Q21. How does biodiversity support agriculture?
Ans: Biodiversity provides crop varieties, pollinators, pest control, and soil fertility.

Q22. Why is biodiversity important economically?
Ans: It provides food, medicines, fuel, timber, and raw materials for industries.

Q23. Mention one aesthetic value of biodiversity.
Ans: Biodiversity provides recreational and aesthetic enjoyment through nature.

Q24. Why is biodiversity ethically important?
Ans: Every species has an inherent right to exist, independent of human use.

Q25. Name one medicinal benefit of biodiversity.
Ans: Many drugs like antibiotics are derived from plants and microorganisms.

Q26. How does biodiversity increase ecosystem productivity?
Ans: Higher biodiversity improves resource use efficiency and ecosystem functioning.

Section D: Loss of Biodiversity (Q27–Q36)

Q27. What is biodiversity loss?
Ans: Biodiversity loss refers to decline or extinction of species and degradation of ecosystems.

Q28. Name the four major causes of biodiversity loss.
Ans: Habitat loss, over-exploitation, alien species invasion, and co-extinctions.

Q29. What is habitat fragmentation?
Ans: Habitat fragmentation is breaking of large habitats into smaller isolated patches.

Q30. Why is habitat loss considered the main cause of extinction?
Ans: It destroys natural living spaces essential for survival and reproduction.

Q31. What is over-exploitation?
Ans: Over-exploitation is excessive harvesting of biological resources beyond sustainable limits.

Q32. Give one example of alien species invasion.
Ans: Lantana camara invading Indian forests is an example.

Q33. What are co-extinctions?
Ans: Co-extinctions occur when extinction of one species leads to extinction of dependent species.

Q34. What is the present rate of species extinction compared to natural rate?
Ans: It is 100–1000 times higher than natural rates.

Q35. Name the term used for major causes of biodiversity loss.
Ans: Evil Quartet.

Q36. How does alien species invasion affect native species?
Ans: Alien species outcompete natives for resources, causing decline.

Section E: Biodiversity Conservation (Q37–Q50)

Q37. What is biodiversity conservation?
Ans: Biodiversity conservation involves protection and sustainable use of biological resources.

Q38. Define in situ conservation.
Ans: In situ conservation protects species in their natural habitats.

Q39. Name two in situ conservation areas.
Ans: National parks and wildlife sanctuaries.

Q40. What is a biosphere reserve?
Ans: A biosphere reserve conserves biodiversity while promoting sustainable use.

Q41. Define ex situ conservation.
Ans: Ex situ conservation protects species outside their natural habitats.

Q42. Give two examples of ex situ conservation.
Ans: Zoological parks and botanical gardens.

Q43. What is a seed bank?
Ans: A seed bank stores seeds of different plant species for future use.

Q44. Why is ex situ conservation important?
Ans: It helps protect endangered species from immediate extinction.

Q45. Which conservation method maintains natural evolution?
Ans: In situ conservation.

Q46. What are biodiversity hotspots?
Ans: Regions with high species richness and endemism under threat.

Q47. Why are hotspots conservation priorities?
Ans: They contain maximum biodiversity in small areas.

Q48. How can humans help conserve biodiversity?
Ans: By sustainable resource use and habitat protection.

Q49. Why is conservation important for future generations?
Ans: It ensures resource availability and ecological stability.

Q50. What is the ultimate goal of biodiversity conservation?
Ans: To maintain ecological balance and sustain life on Earth.

CBSE Exam Note

These very short answer questions (1 mark each) are ideal for quick revision, concept recall, and CBSE Class 12 board examinations, strictly aligned with NCERT Chapter 15 – Biodiversity and Conservation.