Biodiversity and Conservation — Class 12 MCQs with Answers

Biodiversity and Conservation — important questions & MCQs with answers (Class 12 Biology)

6 solved questions from this chapter's difficulty levels, each with its answer and explanation. Tap an option to check yourself.

0 of 6 answered

1. Q1 of 6Easy

   Three levels of biodiversity:

   ATissue, organ, systemBCellular, molecular, atomicCGenetic, species, ecosystemDLocal, regional, global
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   Answer: Genetic, species, ecosystem

   Explanation: Biodiversity has three nested levels: genetic (variation within a species), species (variety across species) and ecosystem (variety of habitats) — not cellular or geographic scales, which aren't recognized categories.

2. Q2 of 6Easy

   Sanctuaries and national parks are:

   AIn-situ conservationBEx-situCBoth in-situ and ex-situDNeither in-situ nor ex-situ
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   Answer: In-situ conservation

   Explanation: National parks and wildlife sanctuaries protect species inside their own natural habitat, making this in-situ conservation — distinct from ex-situ methods like zoos that move organisms out of the wild.

3. Q3 of 6Medium

   India's biodiversity hotspot example:

   ADeccan plateauBThar desertCIndo-Gangetic plainDWestern Ghats
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   Answer: Western Ghats

   Explanation: The Western Ghats is one of India's biodiversity hotspots (with the Himalaya, Indo-Burma and Sundaland) due to high endemism under severe threat; the Deccan plateau and Thar desert are not hotspots.

4. Q4 of 6Medium

   Zoos and seed banks are:

   AIn-situBEx-situ conservationCReserve forestsDSanctuaries
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   Answer: Ex-situ conservation

   Explanation: Zoos, botanical gardens and seed banks hold organisms outside their natural habitat, so they are ex-situ conservation — the opposite of national parks and sanctuaries, which protect species in-situ.

5. Q5 of 6Hard

   Major causes of biodiversity loss ("Evil Quartet"):

   AOnly climateBOnly pollutionCHabitat loss, over-exploitation, alien species, co-extinctionsDSound waves
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   Answer: Habitat loss, over-exploitation, alien species, co-extinctions

   Explanation: Edward Wilson's Evil Quartet names habitat loss and fragmentation, over-exploitation, alien species invasion and co-extinctions as the four drivers of biodiversity loss — habitat loss is the single biggest cause.

6. Q6 of 6Hard

   Earth Summit was held in:

   AGeneva, 2010BStockholm, 2000CParis, 1992DRio de Janeiro, 1992
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   Answer: Rio de Janeiro, 1992

   Explanation: The 1992 Earth Summit at Rio de Janeiro produced the Convention on Biological Diversity; Stockholm and Johannesburg hosted earlier and later summits, so pairing the wrong city with 1992 is the trap.

Biodiversity and Conservation notes: key concepts (Class 12 Biology)

Biodiversity and conservation: genetic, species and ecological levels of diversity and its global patterns (latitudinal gradient, species-area relationship); the causes of loss (the Evil Quartet); and conservation — in situ (hotspots, protected areas, sacred groves) and ex situ (zoos, seed banks, cryopreservation).

Levels of biodiversity

Three levels (E.O. Wilson) — genetic (variation within a species, e.g., Rauwolfia reserpine), species (variety of species) and ecological (of ecosystems).

Species diversity patterns

Diversity is highest in the tropics and falls toward the poles (latitudinal gradient); the Amazon rainforest is the richest and insects are the largest group.

Species-area relationship

On a log-log plot, species richness vs area is a straight line, log S = log C + Z log A; slope Z ≈ 0.1-0.2 for small areas, ~0.6-1.2 for continents.

Rivet popper hypothesis

Ehrlich's analogy — species are rivets in an aeroplane (the ecosystem); losing a few may be safe, but each loss weakens ecosystem function.

Evil Quartet

The four causes of biodiversity loss — habitat loss and fragmentation (the biggest), over-exploitation, alien species invasions and co-extinctions.

Alien species invasion

Introduced species that harm natives; e.g., Nile perch in Lake Victoria wiped out cichlids, and water hyacinth, Lantana and Parthenium in India.

Co-extinction

Extinction of one species triggering the loss of others dependent on it; e.g., a host fish's obligate parasites vanish when the host dies out.

Reasons to conserve

Narrowly utilitarian (food, medicine, timber), broadly utilitarian (pollination, O₂, climate) and ethical (a duty to future generations).

In situ conservation

Protecting species in their natural habitat — biodiversity hotspots, national parks, wildlife sanctuaries, biosphere reserves and sacred groves.

Biodiversity hotspots

Regions with very high endemism AND severe threat; India has Western Ghats-Sri Lanka, Himalaya and Indo-Burma. ~34 globally, on under 2% of land.

Sacred groves

Forest patches protected by local communities on religious grounds (Meghalaya, Western Ghats, Aravallis) — a traditional in situ practice.

Ex situ conservation

Protecting species outside their habitat — zoos, botanical gardens, wildlife safari parks, seed banks and cryopreservation of gametes/tissue.

Endemism

Species found only in a particular geographic area and nowhere else; oceanic islands and hotspots show high endemism.

IUCN Red List

The Red Data Book maintained by IUCN lists threatened species; international trade in endangered species is regulated by CITES.