Conservation: zoos and seed banks

Zoos and seed banks protect species outside their natural habitats. You need to weigh how well they work.

Zoos

Captive breeding: breeding endangered species, using records (studbooks) to pair unrelated animals and keep genetic diversity high, avoiding inbreeding.
Reintroduction: returning animals to the wild. The Arabian oryx became extinct in the wild around 1972; captive-bred animals were reintroduced in Oman from 1982, and in 2011 its IUCN Red List status improved from Endangered to Vulnerable.
Scientific research: on reproduction, behaviour, nutrition and disease.
Education: raising public awareness and funds.

Problems: small captive populations have limited genetic diversity; animals may lack survival skills; the habitat must be protected before reintroduction; welfare and cost.

Seed banks

Seed banks store seeds so plants can be grown again in future. At the Millennium Seed Bank (Wakehurst, UK), seeds are cleaned, X-rayed to discard empty ones, dried at low humidity (15% relative humidity) and stored at -20 °C, which slows metabolism and keeps them viable for many years.

Advantages: many species and much genetic diversity stored in a small space at low cost; seeds can be used for research, restoration and reintroduction.
Seeds are tested regularly for viability (germination tests); when viability falls, plants are grown and fresh seeds collected.
Limitations: some seeds cannot survive drying and freezing; stored seeds do not adapt to changes in the environment; a disaster at one site could lose samples (so duplicates are kept elsewhere).

Worked example

Suggest why a captive breeding programme uses a studbook.

A studbook records each animal's ancestry.
Unrelated animals can be paired.
This keeps genetic diversity high and avoids inbreeding.

Answer: To pair unrelated animals, maintaining genetic diversity.

Key idea: Zoos: captive breeding (studbooks to avoid inbreeding), reintroduction (Arabian oryx), research and education. Seed banks: dried seeds stored at -20 °C, tested for viability; cheap and space-efficient, but some seeds cannot be stored.

Check yourself

Why do zoos keep records of animals' ancestry in captive breeding programmes?
- To increase inbreeding
- To decide ticket prices
- To choose which animals to sell
- To avoid inbreeding and keep genetic diversity high
Show answer
To avoid inbreeding and keep genetic diversity high. Pairing unrelated animals maintains genetic diversity.
Which species was reintroduced to Oman from captive-bred stock after becoming extinct in the wild?
- Giant panda
- Arabian oryx
- African elephant
- Polar bear
Show answer
Arabian oryx. The Arabian oryx was reintroduced in Oman in 1982.
Why are seeds stored dry and at -20 °C?
- To make them germinate faster
- To kill pests by drowning them
- To increase their water content
- To slow metabolism so seeds stay viable for longer
Show answer
To slow metabolism so seeds stay viable for longer. Cold, dry conditions slow chemical reactions and decay.
How do seed banks check that stored seeds are still alive?
- By regular germination tests
- By weighing them
- By counting them
- By measuring their colour
Show answer
By regular germination tests. A sample is germinated to check viability.
Which is a limitation of seed banks?
- They take up huge areas of land
- They store only one species
- Some seeds cannot survive drying and freezing
- Seeds cannot be used for reintroduction
Show answer
Some seeds cannot survive drying and freezing. Some species' seeds die if dried and frozen.
What must be done before a captive-bred species is reintroduced?
- Make sure suitable, protected habitat exists
- Increase hunting in the area
- Remove all other species
- Breed only from two individuals
Show answer
Make sure suitable, protected habitat exists. Animals need safe habitat to survive.
Which is a role of zoos besides breeding?
- Producing meat
- Testing pesticides
- Education and scientific research
- Growing crops
Show answer
Education and scientific research. Zoos raise awareness and study animals.

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Last updated 7 November 2026. Spotted a mistake? Tell us.