Ex-situ Techniques: Zoos, Botanical Gardens, Seed and Gene Banks, Cryopreservation
Biology · Biodiversity and Conservation · NEET
Ex-situ (off-site) techniques protect threatened species AWAY from their natural habitat. NCERT names four practical tools: zoos/botanical gardens/wildlife safari parks (living collections), seed and gene banks (store seeds of many genetic strains), cryopreservation (freeze gametes at very low temperature), plus in vitro fertilisation and tissue culture. Memory hook: "Cold Bank Zoo" - Cryopreservation, seed/gene Banks, and Zoos are the star ex-situ techniques NEET repeats every year.
The three ex-situ pillars NEET tests: living collections (zoos, botanical gardens, safari parks), seed/gene banks (store seeds), and cryopreservation (freeze gametes) with in vitro and tissue culture. Remember: seeds to seed banks, gametes to cryopreservation.
Your doubts, answered
Is a seed bank in-situ or ex-situ? Students mix this up because seeds come from wild plants.
A seed bank is EX-SITU. The seeds are taken OUT of the plant's natural habitat and stored in a controlled facility. NCERT says seeds of different genetic strains of commercially important plants can be kept for long periods in seed banks. Since the material is stored off-site, it is ex-situ - not in-situ.
What is the difference between a seed bank and a gene bank?
A seed bank stores dried seeds (mostly of crop plants and their genetic strains). A gene bank is the broader term - it stores genetic material in any form: seeds, pollen, tissue cultures, or frozen gametes/embryos. So a seed bank is one TYPE of gene bank. Both are ex-situ because the material is kept away from the natural habitat.
Is cryopreservation ex-situ, and what exactly does it store?
Cryopreservation is EX-SITU. NCERT is precise: gametes of threatened species are preserved in viable and fertile condition for long periods using cryopreservation techniques. So it stores GAMETES (and embryos/tissues) at very low temperature - NOT whole seeds. A common trap swaps 'gametes' for 'seeds'; seeds go to seed banks, gametes go to cryopreservation.
Botanical garden vs national park - which one is ex-situ?
Botanical garden is EX-SITU (plants are grown in a special managed setting away from the wild). National park is IN-SITU (the whole ecosystem is protected on-site). NEET repeatedly hides one in-situ item (national park, sanctuary, biosphere reserve, sacred grove) inside a list of ex-situ techniques - spot it and reject it.
Are in vitro fertilisation and tissue culture ex-situ techniques?
Yes. NCERT lists both as advanced ex-situ methods: eggs can be fertilised in vitro, and plants can be propagated using tissue culture (micropropagation). They multiply threatened species outside the natural habitat, so they are ex-situ.
⚠️ The NEET trap ✗ Cryopreservation stores seeds of endangered plants at low temperature. ✓ Cryopreservation stores GAMETES (and embryos/tissues) at very low temperature; SEEDS are stored in seed banks. NCERT wording: gametes are preserved using cryopreservation techniques. 🧠 NEET swaps 'gametes' with 'seeds'. Rule: Cryo = gametes; Seed bank = seeds. Do not merge them.
Real NEET questions
2018
All of the following are included in 'ex-situ conservation' except:
A · Botanical gardens
B · Sacred groves ✓
C · Wildlife safari parks
D · Seed banks
Solution: The question asks for the exception. Sacred groves are forest tracts protected in their natural habitat through religious/cultural tradition - an IN-SITU method - so they are not ex-situ. Botanical gardens, wildlife safari parks and seed banks all maintain organisms away from the natural habitat, so they are genuine ex-situ techniques.
2022
Which of the following is not a method of ex situ conservation?
A · In vitro fertilization
B · National Parks ✓
C · Micropropagation
D · Cryopreservation
Solution: In vitro fertilisation, micropropagation (tissue culture) and cryopreservation are all NCERT ex-situ techniques. National Parks protect species within their natural habitat, making them IN-SITU - so National Parks is the answer to 'not ex-situ'.
2017
Which one of the following is related to Ex-situ conservation of threatened animals and plants?
A · Wildlife Safari parks ✓
B · Biodiversity hot spots
C · Amazon rainforest
D · Himalayan region
Solution: Ex-situ conservation takes threatened species out of their habitat for special care; NCERT names zoological parks, botanical gardens and wildlife safari parks. Biodiversity hotspots, the Amazon rainforest and the Himalayan region are all in-situ (on-site) settings.
Solved Biodiversity and Conservation NEET PYQs
Try the real previous-year questions from this chapter — each with the answer and a full solution.
What are the main ex-situ conservation techniques in NCERT?
Zoological parks (zoos), botanical gardens and wildlife safari parks for living collections; seed banks for genetic strains of plants; and advanced methods - cryopreservation of gametes, in vitro fertilisation of eggs, and tissue culture (micropropagation) of plants.
Why is ex-situ conservation needed if we already have in-situ methods?
When a species is endangered or already extinct in the wild, protecting its habitat is not enough. Ex-situ methods give urgent, special care off-site. NCERT notes many animals extinct in the wild are still maintained in zoological parks.
Does cryopreservation store seeds or gametes?
Gametes (and embryos/tissues), kept viable and fertile at very low temperature. Seeds are stored in seed banks - not by cryopreservation.
Is a seed bank the same as a gene bank?
A seed bank stores seeds; a gene bank is the wider term for storing genetic material in any form (seeds, pollen, tissue, frozen gametes). A seed bank is one kind of gene bank, and both are ex-situ.
Which techniques are the favourite NEET traps here?
NEET hides one in-situ item (national park, sanctuary, biosphere reserve, sacred grove) inside a list of ex-situ methods, and it swaps 'gametes' for 'seeds' in cryopreservation. Watch both.
