Gene bank, cryopreservation and tissue culture are ex-situ approaches of biodiversity conservation. In this approach, threatened animals and plants are. taken out from their natural habitat and placed in special setting where they can be protected and given special care. Now gametes of threatened species can be preserved in viable and fertile condition for long periods using cryopreservation techniques, eggs can be fertilised in vitro and plants can be propagated using tissue culture methods. Gene banks maintain stocks of viable seeds (seed banks), frozen germplasm with whole range of genetic variability.