Below are 60 practice questions on Biodiversity and Conservation, sorted Easy → Hard. Tap “Show answer & explanation” under any question to check yourself. Want the full theory first? Read the Biodiversity and Conservation notes.
🔬 Biology · Class 12 · NEET
Biodiversity and Conservation - Practice Questions with Answers
60 free MCQs on Biodiversity and Conservation with worked answers and explanations. Levels of biodiversity, species richness patterns, threats (HIPPO), and conservation strategies. Always in NEET.
Take the timed Biodiversity and Conservation chapterwise test →Easy - 20 questions
Q1.
An ecosystem consists of:
- A Mainly the living organisms present in an area
- B Mainly the non-living physical factors present
- C Living organisms and their non-living environment
- D Mainly the plant and animal species in a region
Show answer & explanation
Answer: C. Living organisms and their non-living environment
Why: An ecosystem includes all living organisms (biotic) AND their physical environment (abiotic factors like water, temperature, soil).
Q2.
An extinct species is one that:
- A Is currently classified as an endangered species
- B No longer exists anywhere on Earth
- C Exists today mainly in zoos and captive breeding programs
- D Has a population that has been steadily reduced over time
Show answer & explanation
Answer: B. No longer exists anywhere on Earth
Why: Extinction: a species no longer exists anywhere on Earth. The last individual has died. Cannot be recovered.
Q3.
Greenhouse gases include:
- A Oxygen (O<sub>2</sub>) and nitrogen (N<sub>2</sub>)
- B CO<sub>2</sub>, CH<sub>4</sub>, N<sub>2</sub>O, and water vapor
- C Carbon dioxide (CO<sub>2</sub>) mainly
- D Oxygen (O<sub>2</sub>) gas mainly
Show answer & explanation
Answer: B. CO<sub>2</sub>, CH<sub>4</sub>, N<sub>2</sub>O, and water vapor
Why: Greenhouse gases (CO<sub>2</sub>, methane, N<sub>2</sub>O, H<sub>2</sub>O vapor) trap heat in the atmosphere, causing the greenhouse effect.
Q4.
An endangered species is one that:
- A Has already gone largely extinct worldwide
- B Is at high risk of extinction in the near future
- C Has largely recovered its former population size
- D Is native to mainly one single country
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Answer: B. Is at high risk of extinction in the near future
Why: An endangered species is at very high risk of extinction. Conservation efforts aim to prevent their extinction.
Q5.
The water cycle involves:
- A Mainly the rainfall that reaches the ground surface directly
- B Evaporation, condensation, precipitation, and transpiration
- C Mainly the underground movement and storage of groundwater
- D Mainly the circulation pattern driving major ocean currents
Show answer & explanation
Answer: B. Evaporation, condensation, precipitation, and transpiration
Why: Water cycle: evaporation (water → vapor), condensation (vapor → clouds), precipitation (rain/snow), infiltration, and transpiration.
Q6.
National parks conserve biodiversity. This is an example of:
- A Ex-situ conservation outside its habitat
- B In-situ conservation (in natural habitat)
- C Gene bank storage of seed material
- D Captive zoo-based breeding program
Show answer & explanation
Answer: B. In-situ conservation (in natural habitat)
Why: In-situ conservation preserves species in their natural habitats (national parks, wildlife sanctuaries, biosphere reserves).
Q7.
Acid rain is caused by:
- A A gradual buildup of excess atmospheric carbon dioxide alone
- B SO<sub>2</sub> and NOx reacting with water to form H<sub>2</sub>SO<sub>4</sub> and HNO<sub>3</sub>
- C Gradual depletion of the protective stratospheric ozone layer
- D Heavy metal contamination accumulating gradually within rainwater
Show answer & explanation
Answer: B. SO<sub>2</sub> and NOx reacting with water to form H<sub>2</sub>SO<sub>4</sub> and HNO<sub>3</sub>
Why: Acid rain: SO<sub>2</sub> and NOx (from burning fossil fuels) react with water vapor to form sulfuric and nitric acids in rain.
Q8.
The total variety of living organisms present in a region is called:
- A biomass
- B biodiversity
- C biotechnology
- D biome
Show answer & explanation
Answer: B. biodiversity
Why: Biodiversity is the sum of genetic, species and ecosystem diversity in an area.
Q9.
Who coined the popular term "biodiversity"?
- A Edward Wilson
- B some early Greek scholar
- C a plain Indian botanist
- D only a marine ecologist
Show answer & explanation
Answer: A. Edward Wilson
Why: The socio-biologist Edward Wilson popularised the term biodiversity.
Q10.
How many levels of biodiversity are commonly recognised?
- A Three
- B a total of seven
- C around a dozen
- D only two broad ones
Show answer & explanation
Answer: A. Three
Why: Biodiversity is described at genetic, species and ecosystem levels, i.e. three levels.
Q11.
Variation at the level of genes within a species is called what?
- A Genetic diversity
- B plain species variety
- C the wide ecosystem range
- D only habitat variation
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Answer: A. Genetic diversity
Why: Diversity in the number and types of genes within a species is genetic diversity.
Q12.
Which country is one of the world’s megadiverse nations?
- A India
- B a landlocked desert state
- C some small polar island
- D only tiny city nations
Show answer & explanation
Answer: A. India
Why: India is one of the recognised megadiverse countries of the world.
Q13.
Conservation of species in their natural habitat is termed what?
- A In-situ
- B the ex-situ approach
- C a plain zoo method
- D only botanical gardens
Show answer & explanation
Answer: A. In-situ
Why: In-situ conservation protects species within their own natural surroundings.
Q14.
A national park is an example of which conservation type?
- A In-situ
- B the ex-situ approach
- C a simple seed bank
- D only a tissue culture
Show answer & explanation
Answer: A. In-situ
Why: National parks conserve organisms in their natural habitat, so they are in-situ.
Q15.
Which of these is an ex-situ conservation method?
- A Zoo
- B a large national park
- C the vast wildlife sanctuary
- D only sacred forest groves
Show answer & explanation
Answer: A. Zoo
Why: Zoos keep organisms outside their natural habitat, an ex-situ method.
Q16.
The largest number of species belong to which animal group?
- A Insects
- B the plain fish group
- C some large mammals
- D only the amphibians
Show answer & explanation
Answer: A. Insects
Why: Insects form the single largest group of described animal species.
Q17.
Species found in only one geographic area are called what?
- A Endemic
- B the common cosmopolitan
- C a plain migratory type
- D only introduced ones
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Answer: A. Endemic
Why: Endemic species are restricted to a single particular region and found nowhere else.
Q18.
Which document lists the conservation status of species?
- A Red List
- B a plain census book
- C the local field diary
- D only a museum catalogue
Show answer & explanation
Answer: A. Red List
Why: The IUCN Red List records the threat status of species worldwide.
Q19.
Tropical regions generally have how much biodiversity?
- A High
- B rather low overall
- C almost none at all
- D only average amounts
Show answer & explanation
Answer: A. High
Why: Tropical regions show the highest biodiversity of any latitudinal zone.
Q20.
Sacred groves are patches of forest protected by whom?
- A Local people
- B a large mining firm
- C the plain city council
- D only foreign tourists
Show answer & explanation
Answer: A. Local people
Why: Sacred groves are forest tracts protected by local communities on religious grounds.
Medium - 20 questions
Q21.
Ex-situ conservation includes:
- A Designated wildlife sanctuaries within natural habitat
- B National parks protecting natural ecosystems
- C Zoos, botanical gardens, gene banks, seed banks
- D Biosphere reserves protecting natural habitat
Show answer & explanation
Answer: C. Zoos, botanical gardens, gene banks, seed banks
Why: Ex-situ conservation: preservation of species outside their natural habitat (zoos, botanical gardens, seed banks, cryopreservation). Complements in-situ conservation.
Q22.
Trophic cascade occurs when:
- A Mainly the removal of producers from the base of a food web over time
- B A change at one trophic level affects multiple levels (top-down or bottom-up effects)
- C Competition increasing specifically between exactly two competing species nearby
- D Mainly a change occurring at the very base of the food web structure
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Answer: B. A change at one trophic level affects multiple levels (top-down or bottom-up effects)
Why: Trophic cascade: changes at one trophic level ripple through the food web. E.g., removing wolves allows deer to overgraze, reducing vegetation.
Q23.
The IUCN Red List categories for threatened species include (from least to most risk):
- A Endangered, Vulnerable, Critically Endangered
- B Vulnerable, Endangered, Critically Endangered (CR being highest risk before Extinct in Wild)
- C Rare, Threatened, Endangered
- D Near Threatened, Vulnerable, Endangered, Critically Endangered
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Answer: D. Near Threatened, Vulnerable, Endangered, Critically Endangered
Why: IUCN categories in increasing risk: Least Concern, Near Threatened, Vulnerable, Endangered, Critically Endangered, Extinct in Wild, Extinct.
Q24.
The phosphorus cycle lacks a significant:
- A A significant, well-defined soil-based component present within the overall cycle
- B Atmospheric (gaseous) phase -- phosphorus does not enter the atmosphere as a gas
- C A significant, well-defined oceanic phase present within the overall global cycle
- D Any meaningful biological uptake of phosphorus by living organisms each season
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Answer: B. Atmospheric (gaseous) phase -- phosphorus does not enter the atmosphere as a gas
Why: Unlike carbon and nitrogen cycles, the phosphorus cycle has no gaseous phase. Phosphorus moves from rocks to soil to water to organisms and back.
Q25.
Island biogeography theory predicts that species richness on islands depends on:
- A The particular surface colour or visual appearance of the island itself overall
- B Island size and distance from the mainland (immigration and extinction balance)
- C Mainly the surrounding ocean water temperature near the island in question
- D Mainly the level of human settlement activity present on the island itself
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Answer: B. Island size and distance from the mainland (immigration and extinction balance)
Why: Island biogeography (MacArthur and Wilson): species richness is equilibrium between immigration rate (increases with proximity to mainland) and extinction rate (decreases with island size).
Q26.
A biodiversity hotspot must have a large number of species found nowhere else, that is, high:
- A productivity
- B biomass
- C endemism
- D salinity
Show answer & explanation
Answer: C. endemism
Why: Hotspots are defined by high endemism together with a significant threat of habitat loss.
Q27.
Protecting a species within its natural habitat, as in a national park, is called:
- A in situ conservation
- B ex situ conservation
- C cryopreservation
- D tissue culture
Show answer & explanation
Answer: A. in situ conservation
Why: In situ conservation protects organisms in their natural surroundings (national parks, sanctuaries, biosphere reserves).
Q28.
The species-area relationship on a log scale gives what graph?
- A A straight line
- B a plain flat curve
- C some random scatter
- D only a closed loop
Show answer & explanation
Answer: A. A straight line
Why: On a log-log plot species richness versus area yields a straight line.
Q29.
In the species-area equation, the slope is denoted by which letter?
- A z
- B the common letter q
- C a plain symbol k
- D only the letter m
Show answer & explanation
Answer: A. z
Why: In log S = log C + Z log A, Z is the slope (regression coefficient).
Q30.
How many biodiversity hotspots are recognised globally?
- A 34
- B about a hundred
- C roughly a thousand
- D only around five
Show answer & explanation
Answer: A. 34
Why: There are 34 globally recognised biodiversity hotspots for conservation priority.
Q31.
Which is NOT a biodiversity hotspot located in India?
- A Amazon Basin
- B the Western Ghats
- C some Indo-Burma zone
- D only the Himalaya region
Show answer & explanation
Answer: A. Amazon Basin
Why: The Amazon Basin lies in South America, not among India’s hotspots.
Q32.
The Rivet Popper hypothesis was proposed by which scientist?
- A Paul Ehrlich
- B a plain David Tilman
- C only Robert May
- D some early Charles Elton
Show answer & explanation
Answer: A. Paul Ehrlich
Why: Paul Ehrlich framed the Rivet Popper hypothesis on ecosystem stability.
Q33.
About what fraction of global species are found in India?
- A 8.1 percent
- B nearly half of all
- C almost none at all
- D only about forty percent
Show answer & explanation
Answer: A. 8.1 percent
Why: India harbours roughly 8.1 percent of the world’s recorded species diversity.
Q34.
Alien species invasions cause biodiversity loss by which mechanism?
- A Competition
- B a plain overhunting spree
- C only natural disasters
- D some slow soil erosion
Show answer & explanation
Answer: A. Competition
Why: Invasive alien species outcompete and displace native species, causing losses.
Q35.
The evil quartet refers to the causes of what?
- A Biodiversity loss
- B the plain ozone hole
- C a simple food shortage
- D only global warming
Show answer & explanation
Answer: A. Biodiversity loss
Why: The "evil quartet" names the four major drivers of biodiversity loss.
Q36.
Which is NOT part of the evil quartet?
- A Afforestation
- B plain habitat loss
- C the co-extinctions
- D only overexploitation
Show answer & explanation
Answer: A. Afforestation
Why: Afforestation adds trees; it is not a cause in the evil quartet.
Q37.
Cryopreservation of gametes is which kind of conservation?
- A Ex-situ
- B the in-situ way
- C a plain field method
- D only sacred grove care
Show answer & explanation
Answer: A. Ex-situ
Why: Preserving gametes in seed or gene banks is ex-situ conservation.
Q38.
The most species-rich taxonomic group overall is which one?
- A Fungi over mammals
- B a plain algae group
- C only reptile species
- D some slow bacterial mats
Show answer & explanation
Answer: A. Fungi over mammals
Why: Among the given choices fungi far outnumber mammalian species in richness.
Q39.
Amphibians appear especially vulnerable to which threat?
- A Extinction
- B a plain overgrowth
- C only rapid speciation
- D some quick migration
Show answer & explanation
Answer: A. Extinction
Why: Recent data show amphibians are unusually prone to extinction risk.
Q40.
Broad species diversity along latitude is highest where?
- A At the equator
- B near the cold poles
- C a plain mid-desert belt
- D only on high peaks
Show answer & explanation
Answer: A. At the equator
Why: Species diversity peaks near the equator and declines toward the poles.
Hard - 20 questions
Q41.
The intermediate disturbance hypothesis proposes that species diversity is highest:
- A In largely undisturbed, mature climax plant and animal communities over time
- B At intermediate levels of disturbance frequency and intensity (not too high, not too low)
- C Specifically within highly and frequently disturbed environments, generally speaking
- D Mainly at the single maximum possible level of disturbance intensity observed
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Answer: B. At intermediate levels of disturbance frequency and intensity (not too high, not too low)
Why: Intermediate disturbance hypothesis (Connell): moderate disturbances prevent competitive exclusion while maintaining species coexistence. Too little disturbance: competitive exclusion reduces diversity. Too much: most species cannot persist.
Q42.
Metapopulation theory describes:
- A A single, large, and largely continuous population occupying one habitat with no spatial subdivision into separate patches anywhere
- B A network of semi-isolated local populations connected by limited dispersal (colonization and extinction dynamics)
- C Populations that are restricted mainly to oceanic islands, rarely including any mainland or terrestrial populations
- D Populations of species that live mainly in aquatic habitats, excluding most terrestrial and amphibious species
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Answer: B. A network of semi-isolated local populations connected by limited dispersal (colonization and extinction dynamics)
Why: Metapopulation (Levins): multiple subpopulations in patchy habitat connected by dispersal. Local populations go extinct; empty patches recolonized. Overall persistence depends on balance of colonization and extinction.
Q43.
Liebig law of the minimum states:
- A Growth is sometimes thought to be limited specifically by whichever nutrient is present in the greatest abundance overall
- B The scarcest essential nutrient relative to its requirement limits organism growth (limiting factor)
- C All essential nutrients are sometimes thought to contribute roughly equally to limiting an organism's growth rate
- D Organism growth is sometimes thought to be limited mainly by the single nutrient present in maximum supply available
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Answer: B. The scarcest essential nutrient relative to its requirement limits organism growth (limiting factor)
Why: Liebig law of the minimum: growth rate of an organism is determined by the one essential nutrient (or factor) that is in shortest supply relative to the requirement, regardless of others.
Q44.
Extinction debt describes:
- A Money that is formally owed by governments specifically to fund conservation efforts rather than describing any biological time-lag effect on species survival
- B Species that will eventually go extinct due to past habitat loss even if habitat destruction stops now (time lag in extinction)
- C Current extinction rates mainly, without any reference to past habitat loss, omitting the delayed effect that past habitat loss has on future extinctions
- D Mainly extinct mammal species, excluding birds, reptiles, and other taxa, excluding the many other taxonomic groups this delayed-extinction concept applies to
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Answer: B. Species that will eventually go extinct due to past habitat loss even if habitat destruction stops now (time lag in extinction)
Why: Extinction debt: species committed to extinction by past habitat loss but not yet gone. Small, fragmented populations are not immediately viable. Future extinctions are predictable from current habitat reduction.
Q45.
In the species–area relationship, the slope (z value) of the regression line for most taxa over small areas lies between:
- A 0.1 and 0.2
- B 0.6 and 1.2
- C 2 and 4
- D 5 and 10
Show answer & explanation
Answer: A. 0.1 and 0.2
Why: For small areas z is typically 0.1–0.2, regardless of the taxonomic group or region studied.
Q46.
For most taxa on islands, the slope z typically lies in what range?
- A 0.1 to 0.2
- B a wide 5 to 9 band
- C roughly 20 to 30
- D only above one hundred
Show answer & explanation
Answer: A. 0.1 to 0.2
Why: For small areas z usually ranges between 0.1 and 0.2 regardless of taxon.
Q47.
Across very large areas like whole continents z tends toward what?
- A 0.6 to 1.2
- B a plain 0.0 flat
- C only negative values
- D some fixed value of 5
Show answer & explanation
Answer: A. 0.6 to 1.2
Why: For very large areas the slope z becomes steeper, about 0.6 to 1.2.
Q48.
The species-area curve is best described by which equation?
- A S = C A<sup>Z</sup>
- B a plain S = C + A
- C only S equals A minus Z
- D some S = Z over A
Show answer & explanation
Answer: A. S = C A<sup>Z</sup>
Why: The relationship is the power function S = C A raised to the power Z.
Q49.
Estimated global species number according to Robert May is about?
- A 7 million
- B nearly a billion
- C only a few thousand
- D some fixed hundred
Show answer & explanation
Answer: A. 7 million
Why: Robert May conservatively estimated about 7 million total global species.
Q50.
If a habitat shrinks to 10 percent, roughly how many species survive?
- A About 50 percent
- B a plain 90 percent
- C only 5 percent left
- D nearly all of them
Show answer & explanation
Answer: A. About 50 percent
Why: Studies show a tenfold habitat cut leaves roughly half the species.
Q51.
The extinction of a species dependent on a host is called what?
- A Co-extinction
- B the plain overkill
- C only fragmentation
- D some alien invasion
Show answer & explanation
Answer: A. Co-extinction
Why: When an obligate partner dies out its dependent species suffers co-extinction.
Q52.
The passenger pigeon extinction was mainly due to which cause?
- A Overexploitation
- B a plain slow drought
- C only volcanic ash
- D some deep sea change
Show answer & explanation
Answer: A. Overexploitation
Why: Overexploitation by humans drove the passenger pigeon to extinction.
Q53.
How many hotspots collectively cover India’s biodiversity regions?
- A Three
- B about thirty of them
- C only a single one
- D some fixed dozen
Show answer & explanation
Answer: A. Three
Why: India’s biodiversity is covered by three hotspots including the Himalaya.
Q54.
Number of plant species currently facing extinction threat is near?
- A Over 15500
- B a plain 100 species
- C only about ten of them
- D some fixed fifty species
Show answer & explanation
Answer: A. Over 15500
Why: More than 15,500 species including many plants face extinction threat globally.
Q55.
The productivity-stability studies by Tilman showed what for plots?
- A More species, more stable
- B a plain no effect
- C only fewer are stable
- D some random unstable trend
Show answer & explanation
Answer: A. More species, more stable
Why: Tilman found plots with more species showed greater year-to-year stability.
Q56.
Biosphere reserves conserve biodiversity at which broad level?
- A Ecosystem
- B a plain single gene
- C only one lone species
- D some tiny cell organelle
Show answer & explanation
Answer: A. Ecosystem
Why: Biosphere reserves aim to conserve whole ecosystems and their diversity.
Q57.
Which reasons for conserving biodiversity are termed "narrowly utilitarian"?
- A Direct economic use
- B a plain ethical duty
- C only ecosystem services
- D some pure aesthetic joy
Show answer & explanation
Answer: A. Direct economic use
Why: Narrowly utilitarian arguments stress direct economic benefits from nature.
Q58.
Broadly utilitarian arguments emphasise which of the following?
- A Ecosystem services
- B a plain cash crop sale
- C only medicinal product sale
- D some direct timber income
Show answer & explanation
Answer: A. Ecosystem services
Why: Broadly utilitarian arguments highlight ecosystem services like oxygen and pollination.
Q59.
How much oxygen does the Amazon forest reportedly contribute?
- A 20 percent
- B nearly all of it
- C only about one percent
- D some fixed half share
Show answer & explanation
Answer: A. 20 percent
Why: The Amazon rainforest is said to produce about 20 percent of Earth’s oxygen.
Q60.
The ethical argument for conservation stresses what toward species?
- A Intrinsic value
- B a plain resale price
- C only tourism revenue
- D some export earnings
Show answer & explanation
Answer: A. Intrinsic value
Why: The ethical argument holds that every species has intrinsic value worth protecting.