BiologyCBSE Class 12 · Biodiversity and Conservation

In Situ and Ex Situ Conservation of Biodiversity

Q: What is the difference between in situ and ex situ conservation?

In situ conserves species in their natural habitat (national parks, sanctuaries, biosphere reserves, sacred groves); ex situ conserves them outside it (zoos, botanical gardens, seed banks, cryopreservation).

Q: What are biodiversity hotspots?

Regions with very high species richness and high endemism that face accelerated habitat loss; there are 34, three of which cover parts of India.

Q: What are sacred groves?

Forest patches protected by religious and cultural tradition, such as in the Khasi and Jaintia Hills and the Aravalli Hills, which shelter many rare plants.

Q: Why should we conserve biodiversity?

For direct products (narrowly utilitarian), ecosystem services like oxygen and pollination (broadly utilitarian), and because every species has intrinsic value (ethical).

Q: What are Ramsar sites?

Wetlands of international importance designated under the Ramsar Convention on Wetlands (1971); protecting them conserves wetland biodiversity.

Updated 15 October 2026 · Fact-checked

In situ conservation protects species in their natural habitat, through biodiversity hotspots, biosphere reserves, national parks, wildlife sanctuaries, sacred groves and Ramsar wetlands. Ex situ conservation protects threatened species outside their habitat, in zoos, botanical gardens and safari parks, and by cryopreserving gametes, in vitro fertilisation, tissue culture and seed banks.

In situ guards the whole habitat with its species; ex situ takes threatened species out to zoos, gardens and seed banks.

Illustration drawn for QuestionBuddy.

Understand In Situ and Ex Situ Conservation

Why conserve biodiversity? Three reasons.

Narrowly utilitarian: direct economic benefits such as food grains, pulses and fruits; fibre, firewood and building material; industrial raw materials like dyes, resins, tannins, perfumes and lubricants; and medicines. More than 25 per cent of drugs sold worldwide come from plants, and 25,000 plant species contribute to traditional medicines. Bioprospecting explores molecular, genetic and species diversity for products of economic importance.
Broadly utilitarian: ecosystem services: the Amazon forest is estimated to produce about 20 per cent of the oxygen in the atmosphere through photosynthesis; pollination by bees, bumblebees, birds and bats; aesthetic pleasures.
Ethical: every species has intrinsic value; we have a moral duty to care for it and pass on our biological legacy to future generations.

Two strategies.

In situ (on site): protect the whole ecosystem, so the species is protected with its habitat.
Ex situ (off site): take threatened plants and animals out of their natural habitat and keep them in a special setting with special care.

In situ conservation.

Biodiversity hotspots: regions with very high species richness and a high degree of endemism (species found nowhere else), and also regions of accelerated habitat loss. Initially 25 were identified; 9 more were added, giving 34. Three cover India's richest regions: Western Ghats and Sri Lanka, Indo-Burma, and Himalaya. Together all hotspots cover less than 2 per cent of the earth's land, yet hold a very high number of species; strict protection could reduce ongoing mass extinctions by almost 30 per cent.
Legally protected areas in India: biosphere reserves, national parks and wildlife sanctuaries (the NCERT text says India "now has" 14 biosphere reserves, 90 national parks and 448 wildlife sanctuaries; it gives no year for these counts, so quote them as the textbook figures).
Sacred groves: forest tracts protected by religious and cultural tradition, where all trees and wildlife are venerated: Khasi and Jaintia Hills (Meghalaya), Aravalli Hills (Rajasthan), Western Ghats of Karnataka and Maharashtra, and Sarguja, Chanda and Bastar (Madhya Pradesh). Meghalaya's groves are the last refuges of many rare and threatened plants.
Ramsar sites (named in the CBSE syllabus; not described in the NCERT chapter): wetlands of international importance designated under the Ramsar Convention on Wetlands (1971, Ramsar, Iran); protecting them conserves wetland biodiversity, including migratory birds.
The Red Data Book (named in the CBSE syllabus; NCERT cites the IUCN Red List) records species threatened with extinction and their categories, helping set conservation priorities for endangered organisms.

Ex situ conservation.

Zoological parks, botanical gardens and wildlife safari parks; many animals extinct in the wild survive in zoos.
Modern method 1, cryopreservation: gametes of threatened species preserved in viable, fertile condition for long periods.
Modern method 2, in vitro fertilisation of eggs.
Modern method 3, tissue culture to propagate plants.
Modern method 4, seed banks: seeds of different genetic strains of commercially important plants kept for long periods.

International efforts. Biodiversity knows no political boundaries. The Convention on Biological Diversity ('Earth Summit') at Rio de Janeiro, 1992 called on all nations to conserve biodiversity and use it sustainably. At the World Summit on Sustainable Development, Johannesburg, 2002, 190 countries pledged to significantly reduce the rate of biodiversity loss by 2010.

Flow chart: threatened species → can its habitat be saved? → yes: in situ (hotspot, biosphere reserve, national park, sanctuary, sacred grove, Ramsar wetland) → no or too few left: ex situ (zoo, botanical garden, safari park, cryopreservation, IVF, tissue culture, seed bank) → breed and reintroduce when the habitat is secured.

Draw and label: zones of a biosphere reserve (the zoning is standard UNESCO practice; the NCERT chapter does not describe it). Checklist: three concentric zones. Labels: core zone (strictly protected, no human activity), buffer zone (limited research and education), transition zone (human settlements, sustainable use). Title: 'Biosphere reserve: in situ conservation'.

In Situ and Ex Situ Conservation: key facts

In situ vs ex situ: $in situ: protect habitat; ex situ: protect outside habitat$; In situ conserves the whole ecosystem.
Hotspots: $25 + 9 = 34 hotspots; < 2% land; could cut extinctions \approx 30%$; India: Western Ghats and Sri Lanka, Indo-Burma, Himalaya.
Hotspot criteria: $high species richness + high endemism (+ accelerated habitat loss)$; Endemic = found nowhere else.
Ex situ tools: $zoos, botanical gardens, safari parks, cryopreservation, IVF, tissue culture, seed banks$; Gametes are kept viable for long periods by cryopreservation.
Milestones: $Ramsar 1971 (wetlands); Rio 1992 (CBD); Johannesburg 2002 (190 nations, target 2010)$; International conservation efforts.

How to answer In Situ and Ex Situ Conservation questions

Conservation questions ask for reasons, strategies, examples or a choice of method for a case.

1For 'why conserve', give the three arguments: narrowly utilitarian, broadly utilitarian, ethical, each with one example.
2Define in situ and ex situ in one line each and name examples of each.
3For hotspots, give the criteria (richness, endemism), the number (34) and India's three hotspots.
4For sacred groves, name at least two locations and say why they matter.
5For a case, choose in situ if the habitat can be protected; choose ex situ if numbers are tiny or the habitat is lost, and mention cryopreservation or seed banks where relevant.
6Add the international milestones (Ramsar 1971, Rio 1992, Johannesburg 2002) when asked about global efforts.

In Situ and Ex Situ Conservation in real life

The idea, met in an everyday situation. Answer the question in your own words, then compare with the model answer. The one-line hook is what to remember.

Choosing in situ or ex situ conservation

Suppose a rare orchid survives only in a small sacred grove in the Khasi Hills, and a rare wild rice variety grows in a wetland that will soon be drained for a highway.

Recommend a conservation approach for each and explain your choice.

Try it first, then show the solutionSolution

Orchid: in situ. The sacred grove is already protected by tradition; legal protection and community support will keep the orchid with its pollinators and habitat intact. Tissue culture of the orchid can be added as an ex situ backup.
Wild rice: its habitat will be lost, so collect seeds of the different genetic strains for a seed bank (ex situ), and grow plants in a botanical garden or by tissue culture.
If possible, campaign to protect the wetland itself (for example as a Ramsar site), which would conserve the rice in situ along with other wetland species.

Answer: Orchid: in situ in the sacred grove (with tissue-culture backup). Wild rice: ex situ seed bank and garden, plus efforts to protect the wetland.

Memory hook: Save the home if you can; save the seed if you must.

Tricks to remember In Situ and Ex Situ Conservation

Short memory aids. Say each one aloud once, then use it on a question the same day.

In = in its home
In situ: in the original home; Ex situ: exit from home.
Use it when: Defining the two strategies.
W-I-H: India's hotspots
Western Ghats-Sri Lanka, Indo-Burma, Himalaya.
Use it when: Naming India's hotspots.
Ramsar 71, Rio 92, Jo'burg 02
Wetlands first, Earth Summit next, sustainable development pledge last.
Use it when: International milestones.

In Situ and Ex Situ Conservation: solved examples

Ordered from board level to HOTS. Try each one before you open the solution.

Example 1: Classify the strategies · 2 marks · Very short answerBoard level

Classify each of the following as in situ or ex situ conservation and state the basis of your classification: (a) seed bank (b) sacred grove (c) national park (d) cryopreserved gametes of an endangered antelope.

Try it first, then show the solutionSolution

Basis: in situ conservation protects the species in its natural habitat along with the whole ecosystem; ex situ conservation keeps it outside its natural habitat in a special setting with special care (1 mark).
In situ: (b) sacred grove and (c) national park. Ex situ: (a) seed bank and (d) cryopreserved gametes (1 mark).

Answer: In situ: sacred grove, national park (natural habitat). Ex situ: seed bank, cryopreserved gametes (outside the habitat).

Example 2: Hotspots · 3 marks · Short answerBoard level

What are biodiversity hotspots? How many are there, and which of them cover India? Why is protecting them important?

Try it first, then show the solutionSolution

Regions with very high species richness and a high degree of endemism, also facing accelerated habitat loss (1 mark).
34 in all (25 initially, 9 added); India: Western Ghats and Sri Lanka, Indo-Burma, Himalaya (1 mark).
Though covering less than 2% of land, they hold very many species; strict protection could reduce ongoing mass extinctions by almost 30% (1 mark).

Answer: Rich, endemic, threatened regions; 34; three in India; protecting them could cut extinctions by ~30%.

Example 3: Why conserve · 3 marks · Short answerHarder board level

Explain the narrowly utilitarian, broadly utilitarian and ethical arguments for conserving biodiversity, with one example each.

Try it first, then show the solutionSolution

Narrowly utilitarian: direct products such as food, fibre, timber, industrial products and medicines; over 25% of drugs come from plants (1 mark).
Broadly utilitarian: ecosystem services such as oxygen production (Amazon about 20% of atmospheric oxygen) and pollination by bees, birds and bats (1 mark).
Ethical: every species has intrinsic value; we have a moral duty to pass on our biological legacy (1 mark).

Answer: Products (drugs), services (oxygen, pollination), intrinsic value (moral duty).

Example 4: Sacred groves · 2 marks · Very short answerHarder board level

What are sacred groves? Name two regions in India where they are found and state their importance.

Try it first, then show the solutionSolution

Tracts of forest set aside by religious and cultural tradition, where all trees and wildlife are venerated and fully protected (1 mark).
Found in the Khasi and Jaintia Hills (Meghalaya), Aravalli Hills (Rajasthan), Western Ghats (Karnataka, Maharashtra), Sarguja, Chanda and Bastar (Madhya Pradesh); in Meghalaya they are the last refuges of many rare and threatened plants (1 mark).

Answer: Tradition-protected forests (e.g. Khasi and Jaintia Hills, Aravalli Hills) that shelter rare plants.

Example 5: Modern ex situ · 3 marks · Short answerHarder board level

How has ex situ conservation advanced beyond keeping animals in zoos? Explain three techniques.

Try it first, then show the solutionSolution

Cryopreservation keeps gametes of threatened species viable and fertile for long periods (1 mark).
Eggs can be fertilised in vitro, and plants propagated by tissue culture (1 mark).
Seed banks store seeds of different genetic strains of commercially important plants for long periods (1 mark).

Answer: Cryopreservation of gametes, IVF and tissue culture, seed banks.

Example 6: Planning for a near-extinct species · 5 marks · Long answerHOTS / competency

Suppose only 30 individuals of a deer species survive, all in one patch of forest threatened by fire and poaching. Design a combined in situ and ex situ plan, and explain why using only one approach would be risky.

Try it first, then show the solutionSolution

In situ: declare the forest a protected area (national park or sanctuary) with anti-poaching patrols and fire control, so the deer survive with their habitat (1 mark).
Ex situ: move a few individuals to a zoo or breeding centre for captive breeding (1 mark).
Cryopreserve gametes and use in vitro fertilisation to preserve genetic diversity and increase numbers (1 mark).
Reintroduce captive-bred animals into the protected habitat once threats are controlled (1 mark).
Only in situ: one fire or epidemic could wipe out all 30. Only ex situ: the species loses its habitat and natural behaviour, and genetic diversity may fall; together they spread the risk (1 mark).

Answer: Protect the habitat, breed some in captivity, cryopreserve gametes, reintroduce; combining approaches spreads risk.

Where students lose marks in In Situ and Ex Situ Conservation

The slips examiners see most often, and what to write instead.

Mistake: Calling zoos in situ
Students think any protection is in situ.
Wrong working
Zoological parks are in situ conservation.
Right working
Zoos are ex situ; national parks and sanctuaries are in situ.
Do this: Ask: is the organism in its natural home?
Usually costs: 1 mark.
Mistake: Incomplete hotspot definition
Endemism is forgotten.
Wrong working
Hotspots are areas with many species.
Right working
Very high species richness and high endemism (and accelerated habitat loss).
Do this: Richness + endemism.
Usually costs: 1 mark.
Mistake: Wrong Indian hotspots
Eastern Ghats or Sundarbans are listed.
Wrong working
Eastern Ghats and Sundarbans are India's hotspots.
Right working
Western Ghats and Sri Lanka, Indo-Burma, Himalaya.
Do this: W-I-H.
Usually costs: 1 mark.
Mistake: Mixing up the reasons for conservation
Utilitarian categories are confused.
Wrong working
Oxygen from the Amazon is a narrowly utilitarian reason.
Right working
Oxygen and pollination are ecosystem services: broadly utilitarian. Direct products are narrowly utilitarian.
Do this: Products = narrow; services = broad; intrinsic value = ethical.
Usually costs: 1 mark.

Exam tips

Give at least two examples each for in situ and ex situ.
Quote the hotspot facts: 34 hotspots, less than 2% of land, ~30% reduction in extinctions, India's three.
Name sacred grove regions precisely.
Mention cryopreservation, IVF, tissue culture and seed banks as modern ex situ methods.
For international efforts, give Rio 1992 and Johannesburg 2002 with what they called for.

Practice questions on In Situ and Ex Situ Conservation

Write each answer on paper first. Open the hint only if you are stuck, and the answer only when you have finished.

Q1 · 1 mark · MCQBoard level
Which of these is an ex situ method of conservation?
(a) Sacred grove (b) National park (c) Seed bank (d) Biosphere reserve
Hint
Off site.
Answer
(c) Seed bank.
Q2 · 1 mark · Assertion-reasonHarder board level
Assertion (A): Strict protection of biodiversity hotspots could reduce ongoing mass extinctions by almost 30 per cent.
Reason (R): Hotspots cover less than 2 per cent of the earth's land but hold an extremely high number of species.
(a) Both A and R are true and R is the correct explanation of A.
(b) Both A and R are true but R is not the correct explanation of A.
(c) A is true but R is false.
(d) A is false but R is true.
Hint
Concentration of species.
Answer
(a).
Q3 · 3 marks · Short answerHarder board level
Name the international conventions or summits held in 1971, 1992 and 2002 that relate to biodiversity, and state one outcome of each.
Hint
Ramsar, Rio, Johannesburg.
Answer
1971: Ramsar Convention (Ramsar, Iran) for conserving wetlands of international importance (Ramsar sites). 1992: Convention on Biological Diversity, the Earth Summit at Rio de Janeiro, calling on all nations to conserve biodiversity and use it sustainably. 2002: World Summit on Sustainable Development, Johannesburg, where 190 countries pledged to significantly reduce the rate of biodiversity loss by 2010.
Q4 · 2 marks · Very short answerBoard level
What is bioprospecting? Why do supporters argue that nations rich in biodiversity should benefit from it?
Hint
Economic products from diversity.
Answer
Bioprospecting is exploring molecular, genetic and species-level diversity for products of economic importance (such as drugs). Since such countries hold and conserve the biodiversity, they argue that they should share in the economic benefits.
Q5 · 4 marks · Case-basedHarder board level
Read and answer.
Suppose a state forest department plans: (i) a large protected area with a strictly protected core, a buffer used for research and a transition zone with villages; (ii) a forest patch protected by villagers who believe it is the abode of a deity; (iii) a centre storing frozen sperm and eggs of an endangered antelope.
(a) Name (i) and its zones. (1)
(b) Name (ii) and give one state where such patches are common. (1)
(c) Classify (iii) and explain its advantage. Why can't it replace (i)? (2)
Hint
Biosphere reserve; sacred grove; cryopreservation.
Answer
(a) Biosphere reserve: core, buffer and transition zones. (b) Sacred grove; e.g. Meghalaya (Khasi and Jaintia Hills) or Rajasthan (Aravalli Hills). (c) Ex situ conservation by cryopreservation: gametes stay viable for long periods and can be used for in vitro fertilisation to rebuild the population. It cannot replace the biosphere reserve because the species also needs a natural habitat with its food, interactions and behaviour; frozen gametes alone do not conserve the ecosystem.
Q6 · 2 marks · Very short answerHOTS / competency
Suppose a plant breeder wants to preserve 500 traditional rice varieties that farmers have stopped growing. Which method is best, and why? Name one other method that could help.
Hint
Genetic strains of crops.
Answer
A seed bank: seeds of different genetic strains of commercially important plants can be stored for long periods, preserving genetic diversity cheaply in little space. Tissue culture (or growing them in field gene banks/botanical gardens) could also help.

Test your recall

Answer in your head or on paper first, then open the card. Pulling an answer out of memory makes it stick far better than re-reading.

1.How many biodiversity hotspots are there?Show answer
34.
2.Name India's three hotspots.Show answer
Western Ghats and Sri Lanka, Indo-Burma, Himalaya.
3.Name two sacred grove regions.Show answer
Khasi and Jaintia Hills (Meghalaya), Aravalli Hills (Rajasthan).
4.Where was the Earth Summit held in 1992?Show answer
Rio de Janeiro.
5.What does cryopreservation preserve?Show answer
Gametes of threatened species in a viable, fertile condition.
6.What share of oxygen is the Amazon estimated to produce?Show answer
About 20 per cent.

In Situ and Ex Situ Conservation: frequently asked questions

What is the difference between in situ and ex situ conservation?

In situ conserves species in their natural habitat (national parks, sanctuaries, biosphere reserves, sacred groves); ex situ conserves them outside it (zoos, botanical gardens, seed banks, cryopreservation).

What are biodiversity hotspots?

Regions with very high species richness and high endemism that face accelerated habitat loss; there are 34, three of which cover parts of India.

What are sacred groves?

Forest patches protected by religious and cultural tradition, such as in the Khasi and Jaintia Hills and the Aravalli Hills, which shelter many rare plants.

Why should we conserve biodiversity?

For direct products (narrowly utilitarian), ecosystem services like oxygen and pollination (broadly utilitarian), and because every species has intrinsic value (ethical).

What are Ramsar sites?

Wetlands of international importance designated under the Ramsar Convention on Wetlands (1971); protecting them conserves wetland biodiversity.