Part 1 – Concept of Biodiversity (25 MCQs)
Chapter 13 – Biodiversity and Its Conservation (NCERT Class 12 Biology) systematically in 8 Parts.
Subtopic Breakdown (NCERT-Based)
- Concept of Biodiversity (definition, genetic, species, ecological diversity, global species estimates, patterns)
- Patterns of Biodiversity (latitudinal gradients, species–area relationships, important observations by Alexander von Humboldt)
- Importance of Biodiversity (ecosystem services, ethical, aesthetic, ecological roles, Paul Ehrlich’s rivet popper hypothesis)
- Loss of Biodiversity (causes: habitat loss, overexploitation, alien species invasions, co-extinctions, etc.)
- Biodiversity Conservation (in-situ and ex-situ, protected areas, strategies)
- Biodiversity Hotspots in India (Indo-Burma, Himalaya, Indo-Malayan, Western Ghats)
- Endangered Organisms, Extinction & Red Data Book
- Sacred Groves, Biosphere Reserves, National Parks, Wildlife Sanctuaries & Ramsar Sites
Part 1 – Concept of Biodiversity (25 MCQs)
Q1. Which of the following best defines biodiversity?
a) The number of individuals of a species in an area
b) Variety of organisms and ecosystems present on Earth
c) Only genetic variation among populations
d) Population size of endangered species
Answer: b) Variety of organisms and ecosystems present on Earth
Explanation:
- (a) Incorrect → Population size refers to abundance, not biodiversity.
- (b) Correct → Biodiversity includes genetic, species, and ecological diversity.
- (c) Incorrect → Genetic variation is just one level.
- (d) Incorrect → Biodiversity isn’t limited to endangered species.
Q2. Which level of biodiversity refers to the diversity of habitats, communities, and ecosystems?
a) Genetic diversity
b) Species diversity
c) Ecological diversity
d) Phylogenetic diversity
Answer: c) Ecological diversity
Explanation:
- (a) Incorrect → Genetic diversity = variation in genes within species.
- (b) Incorrect → Species diversity = variety of species in a region.
- (c) Correct → Ecological diversity = variety of ecosystems and ecological niches.
- (d) Incorrect → Phylogenetic diversity = evolutionary relationships.
Q3. The highest biodiversity is generally found at which level?
a) Genetic diversity
b) Species diversity
c) Ecological diversity
d) All of the above
Answer: d) All of the above
Explanation:
- (a) Partial → Genetic variation is high in outbreeding species.
- (b) Partial → Species diversity is the most visible component.
- (c) Partial → Ecological diversity contributes significantly.
- (d) Correct → Biodiversity encompasses all three levels.
Q4. India is one of the _____ megadiversity countries in the world.
a) 10
b) 12
c) 17
d) 25
Answer: c) 17
Explanation:
- (a) Incorrect → Not 10.
- (b) Incorrect → Not 12.
- (c) Correct → India is among 17 megadiverse nations.
- (d) Incorrect → 25 is not a recognized classification.
Q5. Which group contributes the maximum number of species described globally?
a) Fungi
b) Insects
c) Vertebrates
d) Algae
Answer: b) Insects
Explanation:
- (a) Incorrect → Fungi are diverse but fewer.
- (b) Correct → Insects alone account for >70% of all described species.
- (c) Incorrect → Vertebrates form only ~5%.
- (d) Incorrect → Algae are less diverse.
Q6. What is the estimated total number of species present on Earth according to Robert May?
a) 1.5 million
b) 7 million
c) 100 million
d) 8.7 million
Answer: b) 7 million
Explanation:
- (a) Incorrect → 1.5 million = described species.
- (b) Correct → Robert May estimated ~7 million species.
- (c) Incorrect → 100 million is an overestimate.
- (d) Incorrect → 8.7 million is a newer estimate, but NCERT mentions 7 million.
Q7. Which of the following is NOT a level of biodiversity?
a) Genetic diversity
b) Species diversity
c) Molecular diversity
d) Ecological diversity
Answer: c) Molecular diversity
Explanation:
- (a) Correct → Genetic = variation in genes.
- (b) Correct → Species = number and abundance.
- (c) Correct answer → Molecular diversity is not a standard category.
- (d) Correct → Ecological = ecosystem diversity.
Q8. In India, which region is richest in biodiversity?
a) Thar Desert
b) Himalayas
c) Indo-Gangetic Plain
d) Western Ghats
Answer: d) Western Ghats
Explanation:
- (a) Incorrect → Thar desert is species-poor.
- (b) Incorrect → Himalayas are rich but less than Western Ghats.
- (c) Incorrect → Indo-Gangetic plain is cultivated, low diversity.
- (d) Correct → Western Ghats are a biodiversity hotspot.
Q9. Which is an example of genetic diversity?
a) Variety of ecosystems in India
b) Tiger, elephant, lion in a forest
c) Different rice varieties grown in India
d) All national parks in India
Answer: c) Different rice varieties grown in India
Explanation:
- (a) Incorrect → That is ecological diversity.
- (b) Incorrect → That is species diversity.
- (c) Correct → Genetic variation in rice varieties.
- (d) Incorrect → National parks = conservation, not genetic diversity.
Q10. Which of the following correctly matches biodiversity level and example?
a) Genetic diversity – Wheat varieties
b) Species diversity – Western Ghats vs Arctic
c) Ecological diversity – Desert, rainforest, mangroves
d) All of the above
Answer: d) All of the above
Explanation:
- (a) Correct → Wheat varieties differ genetically.
- (b) Correct → Species richness varies geographically.
- (c) Correct → Ecological diversity covers multiple ecosystems.
- (d) Correct → All examples are valid.
Q11. Which of the following is NOT an example of species diversity?
a) Frogs, snakes, and lizards in a forest
b) Different breeds of dogs
c) Birds, insects, and mammals in a sanctuary
d) Coral reef species variety
Answer: b) Different breeds of dogs
Explanation:
- (a) Incorrect → Different animals = species diversity.
- (b) Correct → Dog breeds are genetic diversity, not species.
- (c) Incorrect → Variety of species = species diversity.
- (d) Incorrect → Coral reefs = species-rich ecosystems.
Q12. Which of the following best represents ecological diversity?
a) Different maize hybrids
b) Various species of orchids in Arunachal Pradesh
c) Tropical rainforest, desert, and mangroves in India
d) Number of fish species in the ocean
Answer: c) Tropical rainforest, desert, and mangroves in India
Explanation:
- (a) Incorrect → Genetic diversity.
- (b) Incorrect → Species diversity.
- (c) Correct → Multiple ecosystems = ecological diversity.
- (d) Incorrect → Species diversity.
Q13. Who estimated that there are about 7 million species on Earth?
a) Robert May
b) E.O. Wilson
c) Charles Darwin
d) Alfred Wallace
Answer: a) Robert May
Explanation:
- (a) Correct → Robert May estimated ~7 million species.
- (b) Incorrect → E.O. Wilson worked on biodiversity conservation.
- (c) Incorrect → Darwin explained evolution, not species count.
- (d) Incorrect → Wallace contributed to biogeography.
Q14. The total number of species that have been described so far on Earth is about:
a) 7 million
b) 8.7 million
c) 1.5 million
d) 5 million
Answer: c) 1.5 million
Explanation:
- (a) Incorrect → Estimated total = 7 million.
- (b) Incorrect → Newer estimates suggest 8.7 million, but NCERT says 7 million.
- (c) Correct → 1.5 million species actually described.
- (d) Incorrect → 5 million not a standard value.
Q15. Which type of biodiversity is most commonly considered when we say “biodiversity”?
a) Genetic diversity
b) Species diversity
c) Ecological diversity
d) Habitat diversity
Answer: b) Species diversity
Explanation:
- (a) Incorrect → Genetic is less visible.
- (b) Correct → Species diversity is the most common measure.
- (c) Incorrect → Ecological = ecosystem-level.
- (d) Incorrect → Habitat diversity = subset of ecological diversity.
Q16. Which of the following is the most species-rich taxonomic group?
a) Mammals
b) Birds
c) Insects
d) Amphibians
Answer: c) Insects
Explanation:
- (a) Incorrect → Mammals have ~4,000 species.
- (b) Incorrect → Birds have ~9,000 species.
- (c) Correct → Insects = over 1 million described species.
- (d) Incorrect → Amphibians are fewer in number.
Q17. Which of the following is NOT true about biodiversity?
a) It includes all life forms on Earth
b) It is uniform across the globe
c) It provides ecological balance
d) It includes genetic, species, and ecological levels
Answer: b) It is uniform across the globe
Explanation:
- (a) Correct → Biodiversity = all life forms.
- (b) Correct answer → Biodiversity is not uniform; it varies geographically.
- (c) Correct → Maintains ecosystems.
- (d) Correct → Defined at 3 levels.
Q18. Which biome shows the highest species diversity?
a) Tropical rainforest
b) Desert
c) Tundra
d) Grassland
Answer: a) Tropical rainforest
Explanation:
- (a) Correct → Highest species richness, esp. Amazon rainforest.
- (b) Incorrect → Deserts = species-poor.
- (c) Incorrect → Tundra = very low diversity.
- (d) Incorrect → Grasslands = moderate diversity.
Q19. Which is the most diverse ecosystem on Earth?
a) Coral reefs
b) Tundra
c) Desert
d) Taiga
Answer: a) Coral reefs
Explanation:
- (a) Correct → Coral reefs = “tropical rainforests of the sea.”
- (b) Incorrect → Tundra = low species count.
- (c) Incorrect → Desert = limited species.
- (d) Incorrect → Taiga = low diversity.
Q20. Which of the following pairs is correct?
a) Genetic diversity – desert, rainforest
b) Species diversity – two rice varieties
c) Ecological diversity – tundra, grassland, desert
d) Species diversity – dog breeds
Answer: c) Ecological diversity – tundra, grassland, desert
Explanation:
- (a) Incorrect → Desert/rainforest = ecosystems, not genetic.
- (b) Incorrect → Two rice varieties = genetic diversity.
- (c) Correct → Ecosystems = ecological diversity.
- (d) Incorrect → Dog breeds = genetic diversity.
Q21. Which Indian ecosystem is richest in species diversity?
a) Desert ecosystem
b) Mangroves
c) Tropical rainforest in North-East India
d) Grasslands
Answer: c) Tropical rainforest in North-East India
Explanation:
- (a) Incorrect → Desert = poor diversity.
- (b) Incorrect → Mangroves = rich but not highest.
- (c) Correct → North-East India tropical rainforests = species-rich.
- (d) Incorrect → Grasslands = moderate.
Q22. Which of the following is the best measure of biodiversity?
a) Population size
b) Species richness
c) Biomass of organisms
d) Primary productivity
Answer: b) Species richness
Explanation:
- (a) Incorrect → Population size ≠ biodiversity.
- (b) Correct → Number of species present = primary measure.
- (c) Incorrect → Biomass shows productivity, not diversity.
- (d) Incorrect → Productivity ≠ biodiversity.
Q23. Which of the following statements is TRUE?
a) Species diversity increases towards poles
b) Biodiversity is uniform in all habitats
c) Tropical regions have the highest biodiversity
d) Temperate regions have highest genetic diversity
Answer: c) Tropical regions have the highest biodiversity
Explanation:
- (a) Incorrect → Diversity decreases towards poles.
- (b) Incorrect → Biodiversity varies.
- (c) Correct → Latitudinal gradient favors tropics.
- (d) Incorrect → Tropics, not temperate regions, have higher diversity.
Q24. Which one of the following is NOT a component of biodiversity?
a) Species richness
b) Genetic variability
c) Ecosystem diversity
d) Climatic stability
Answer: d) Climatic stability
Explanation:
- (a) Correct → Species richness = component.
- (b) Correct → Genetic variability = component.
- (c) Correct → Ecosystem diversity = component.
- (d) Correct answer → Climate is not part of biodiversity.
Q25. Which one of the following organisms represents genetic diversity in India?
a) Different species of amphibians in Western Ghats
b) Several varieties of mango grown in India
c) Desert, forest, mangroves in Rajasthan
d) Fish, frog, and snake in a pond
Answer: b) Several varieties of mango grown in India
Explanation:
- (a) Incorrect → Species diversity.
- (b) Correct → Varieties within mango = genetic diversity.
- (c) Incorrect → Ecological diversity.
- (d) Incorrect → Species diversity.
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