Write an explanatory note on Ex situ conservation.

(N/A) Ex situ (off-site) conservation involves placing threatened animals and plants in special care units for their protection.
Ex situ conservation includes off-site collections and gene banks.
Off-site Collections: These are live collections of wild and domestic species in botanical gardens,zoological parks,wildlife safari parks,etc.
India has $355$ parks where animals that have become extinct in the wild are maintained,and $35$ botanical gardens where plant species are protected.
Gene Banks: These are places where gametes are protected and maintained by stocking viable seeds (seed banks),tissue culture,and frozen germplasm with a full range of genetic variability. These include:
$(a)$ Seed Bank: Storing different genetic strains of commercially important plants as seeds is one of the most widespread and valuable ex situ conservation strategies.
$(b)$ Tissue Culture: Plant tissue culture is widely used to produce clones of a plant through a method known as micropropagation. This method is useful for maintaining a large number of genotypes in a small area,rapid multiplication of endangered species,and hybrid rescue (e.g.,banana and potato).
$(c)$ Cryopreservation: This is a method of in vitro conservation in liquid $N_2$ at a temperature of $-196^{\circ}C$ in a controlled-rate freezer for vegetatively propagated crops and storing other biological material.