Chapter 15: Biodiversity and Conservation – MCQs with Answers & Explanations

CBSE Class 12 Biology MCQs – Biodiversity and Conservation (NCERT Based)

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

CBSE Class 12 Biology Chapter 15 MCQs with Answers and Explanations – 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 Relevance: CBSE Class 12 Board Exams, School Tests, Conceptual Foundation for NEET

Multiple Choice Questions (MCQs) with Answers & Explanations

(50 MCQs strictly aligned with NCERT concepts, each with concept-clearing explanations)

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

Q1. Biodiversity refers to:
A. Variety of plants only
B. Variety of animals only
C. Variety of life at all levels
D. Variety of ecosystems only

Correct Answer: C
Explanation: Biodiversity includes genetic, species, and ecosystem diversity.

Q2. Which is NOT a level of biodiversity?
A. Genetic diversity
B. Species diversity
C. Population diversity
D. Ecosystem diversity

Correct Answer: C
Explanation: Population diversity is not classified as a level in NCERT.

Q3. Variation in genes within a species is called:
A. Species diversity
B. Ecosystem diversity
C. Genetic diversity
D. Community diversity

Correct Answer: C
Explanation: Genetic diversity helps species adapt and survive.

Q4. Which ecosystem shows maximum species diversity?
A. Tundra
B. Desert
C. Tropical rainforest
D. Temperate forest

Correct Answer: C
Explanation: Tropical rainforests have stable climate and high productivity.

Q5. India is considered a mega-diverse country because it:
A. Has largest population
B. Covers large land area
C. Has high species diversity
D. Has many national parks

Correct Answer: C
Explanation: India harbors ~8% of global species diversity.

Q6. Species richness refers to:
A. Population size
B. Number of species
C. Genetic variation
D. Ecosystem variety

Correct Answer: B
Explanation: Species richness is the count of species in an area.

Q7. Species evenness indicates:
A. Number of ecosystems
B. Genetic variation
C. Relative abundance of species
D. Population growth

Correct Answer: C
Explanation: Evenness reflects distribution of individuals among species.

Q8. Which region has lowest biodiversity?
A. Tropics
B. Equator
C. Poles
D. Coastal regions

Correct Answer: C
Explanation: Extreme climatic conditions reduce biodiversity at poles.

Q9. Endemic species are:
A. Found worldwide
B. Migratory species
C. Restricted to specific regions
D. Artificially introduced species

Correct Answer: C
Explanation: Endemic species have limited geographical distribution.

Q10. Loss of which diversity affects adaptability most?
A. Species diversity
B. Ecosystem diversity
C. Genetic diversity
D. Community diversity

Correct Answer: C
Explanation: Genetic diversity enables adaptation and survival.

Section B: Patterns of Biodiversity (Q11–Q18)

Q11. Biodiversity increases from poles to equator due to:
A. Lower productivity
B. Stable climate
C. Short evolutionary time
D. Less sunlight

Correct Answer: B
Explanation: Stable climate and high productivity promote diversity.

Q12. Latitudinal gradient explains:
A. Species extinction
B. Habitat loss
C. Biodiversity distribution
D. Conservation methods

Correct Answer: C
Explanation: It explains variation in biodiversity with latitude.

Q13. Species–area relationship was proposed by:
A. Darwin
B. Wallace
C. Humboldt
D. Mendel

Correct Answer: C
Explanation: Alexander von Humboldt described this relationship.

Q14. Species–area relationship is expressed as:
A. S = A + Z
B. S = CAᶻ
C. S = Z/A
D. S = A/C

Correct Answer: B
Explanation: NCERT formula linking species richness and area.

Q15. Steeper slope (Z value) is seen in:
A. Small islands
B. Local forests
C. Continents
D. Gardens

Correct Answer: C
Explanation: Large areas show rapid species increase.

Q16. Biodiversity hotspots are characterized by:
A. Low endemism
B. High species richness and threat
C. Large area coverage
D. Low human impact

Correct Answer: B
Explanation: Hotspots have high endemism and habitat loss.

Q17. Which is a biodiversity hotspot in India?
A. Thar Desert
B. Western Ghats
C. Indo-Gangetic plain
D. Deccan plateau

Correct Answer: B
Explanation: Western Ghats has high endemism and richness.

Q18. Islands show high endemism because of:
A. High rainfall
B. Isolation
C. Large size
D. Human activity

Correct Answer: B
Explanation: Isolation promotes speciation.

Section C: Importance of Biodiversity (Q19–Q26)

Q19. Biodiversity enhances ecosystem stability by:
A. Increasing population
B. Reducing productivity
C. Improving resilience
D. Decreasing interactions

Correct Answer: C
Explanation: Diverse ecosystems recover faster from disturbances.

Q20. Pollination is an example of:
A. Economic value
B. Cultural value
C. Ecosystem service
D. Ethical value

Correct Answer: C
Explanation: Pollination supports agriculture and ecosystems.

Q21. Medicinal importance of biodiversity includes:
A. Timber production
B. Antibiotics
C. Tourism
D. Climate regulation

Correct Answer: B
Explanation: Many medicines are derived from plants and microbes.

Q22. Ethical importance of biodiversity means:
A. Commercial use
B. Human dominance
C. Right of species to exist
D. Aesthetic enjoyment

Correct Answer: C
Explanation: Every species has intrinsic value.

Q23. Biodiversity supports agriculture by:
A. Increasing pollution
B. Reducing soil fertility
C. Providing crop varieties
D. Eliminating pests

Correct Answer: C
Explanation: Genetic diversity improves crop yield and resistance.

Q24. Which biodiversity value includes recreation and tourism?
A. Economic
B. Aesthetic
C. Ethical
D. Ecological

Correct Answer: B
Explanation: Natural beauty provides aesthetic benefits.

Q25. Higher biodiversity leads to:
A. Lower productivity
B. Ecosystem imbalance
C. Efficient resource use
D. Species extinction

Correct Answer: C
Explanation: Diverse systems use resources efficiently.

Q26. Biodiversity contributes to climate regulation mainly through:
A. Deserts
B. Grasslands
C. Forests
D. Mountains

Correct Answer: C
Explanation: Forests regulate carbon and temperature.

Section D: Loss of Biodiversity (Q27–Q36)

Q27. Current extinction rate is how many times higher than natural rate?
A. 10–50
B. 50–100
C. 100–1000
D. 1000–5000

Correct Answer: C
Explanation: NCERT states 100–1000 times higher.

Q28. Major cause of biodiversity loss is:
A. Pollution
B. Habitat loss
C. Climate change
D. Disease

Correct Answer: B
Explanation: Habitat loss is the primary cause.

Q29. Breaking habitats into smaller patches is called:
A. Over-exploitation
B. Co-extinction
C. Fragmentation
D. Invasion

Correct Answer: C
Explanation: Fragmentation isolates populations.

Q30. Overfishing is an example of:
A. Habitat loss
B. Alien invasion
C. Over-exploitation
D. Co-extinction

Correct Answer: C
Explanation: Excessive use reduces population size.

Q31. Lantana camara is an example of:
A. Endemic species
B. Keystone species
C. Alien invasive species
D. Pollinator

Correct Answer: C
Explanation: It displaces native flora.

Q32. Co-extinction occurs when:
A. Predator disappears
B. Climate changes
C. Dependent species go extinct together
D. Habitat fragments

Correct Answer: C
Explanation: One species’ extinction leads to another’s loss.

Q33. The ‘Evil Quartet’ does NOT include:
A. Habitat loss
B. Over-exploitation
C. Alien invasion
D. Global warming

Correct Answer: D
Explanation: Global warming is not part of Evil Quartet.

Q34. Endemic species are more vulnerable because:
A. They migrate
B. They have wide distribution
C. They have limited range
D. They reproduce slowly

Correct Answer: C
Explanation: Restricted distribution increases extinction risk.

Q35. Which activity causes maximum habitat destruction?
A. Grazing
B. Agriculture expansion
C. Photosynthesis
D. Respiration

Correct Answer: B
Explanation: Agriculture and urbanization destroy habitats.

Q36. Alien species invasion mainly affects biodiversity by:
A. Increasing resources
B. Supporting natives
C. Outcompeting native species
D. Improving productivity

Correct Answer: C
Explanation: Invasives displace native species.

Section E: Biodiversity Conservation (Q37–Q50)

Q37. Conservation of species in natural habitat is called:
A. Ex situ conservation
B. In situ conservation
C. Artificial selection
D. Habitat fragmentation

Correct Answer: B
Explanation: In situ protects species where they naturally live.

Q38. Which is an in situ conservation area?
A. Zoo
B. Botanical garden
C. National park
D. Gene bank

Correct Answer: C
Explanation: National parks conserve ecosystems.

Q39. Ex situ conservation includes:
A. Wildlife sanctuary
B. Biosphere reserve
C. Zoological park
D. National park

Correct Answer: C
Explanation: Zoos protect species outside habitats.

Q40. Seed banks help in conserving:
A. Ecosystems
B. Animals
C. Genetic diversity
D. Habitats

Correct Answer: C
Explanation: Seeds preserve plant genetic material.

Q41. Biosphere reserves promote:
A. Only wildlife protection
B. Sustainable human activities
C. Industrial development
D. Urban expansion

Correct Answer: B
Explanation: They balance conservation and sustainable use.

Q42. Which conservation method allows natural evolution?
A. Ex situ
B. Artificial breeding
C. In situ
D. Cryopreservation

Correct Answer: C
Explanation: Natural habitats support evolution.

Q43. Cryopreservation is used for conserving:
A. Ecosystems
B. Seeds only
C. Gametes and embryos
D. Habitats

Correct Answer: C
Explanation: It preserves biological material at very low temperatures.

Q44. Biodiversity hotspots should be conserved because they:
A. Cover large area
B. Are less threatened
C. Have high endemism
D. Have low diversity

Correct Answer: C
Explanation: They contain unique species under threat.

Q45. Ultimate aim of biodiversity conservation is to:
A. Stop evolution
B. Increase human population
C. Maintain ecological balance
D. Eliminate predators

Correct Answer: C
Explanation: Conservation ensures sustainability and balance.

Q46. Which conservation method is cost-effective long term?
A. Ex situ
B. In situ
C. Cryopreservation
D. Zoos

Correct Answer: B
Explanation: In situ conserves whole ecosystems naturally.

Q47. Botanical gardens mainly conserve:
A. Animals
B. Ecosystems
C. Plant species
D. Microbes

Correct Answer: C
Explanation: They preserve plant diversity.

Q48. Conservation is necessary because biodiversity:
A. Has no role
B. Supports life systems
C. Slows evolution
D. Reduces productivity

Correct Answer: B
Explanation: Biodiversity supports ecosystems and human survival.

Q49. Which approach combines conservation with development?
A. Wildlife sanctuary
B. Zoo
C. Biosphere reserve
D. Seed bank

Correct Answer: C
Explanation: Biosphere reserves allow sustainable use.

Q50. Human role in conservation includes:
A. Overuse of resources
B. Habitat destruction
C. Sustainable practices
D. Species extinction

Correct Answer: C
Explanation: Sustainable use helps conserve biodiversity.

CBSE Exam Tip

These MCQs are ideal for board exam objective sections, quick revision, and concept strengthening, strictly aligned with NCERT Biology Chapter 15 – Biodiversity and Conservation.

Targeting Exams

CBSE Class 12 Biology Board Examination
CBSE Pre-Board & Unit Tests
Term-wise School Assessments
NEET (UG) – Ecology & Environment Conceptual Foundation
Other Class 12 Medical Entrance Preparations

Related Keyphrases

CBSE Class 12 Biology Chapter 15 MCQs
Biodiversity and Conservation MCQs with answers
NCERT Biodiversity MCQs Class 12
Ecology MCQs Class 12 Biology
Biodiversity conservation objective questions
In situ and ex situ conservation MCQs
Biodiversity loss and hotspots MCQs