There are many animals that have become extinct in the wild but continue to be maintained in Zoological park.
i) What type of biodiversity conservation (off-site conservation). In this approach, threatened plants and animals are taken out of their natural habital and placed in suitable setting and given special care.
ii) Cryopreservation and tissue culture are two way that help in ex-situ connservation. In crypreservation, gametes of threatened species are preserved in viable and fertile condtions at sub-zero temperature, which help in preserving these cells for longer period. In tissue culture, plants are propogated from a small mass of tissue, called callus.