$A$ cryptogram has got how many pairs of information?

Under whose guidance do zoological parks operate?

How are the treatises prepared by $Bentham$ and $Hooker$ useful in the field of botany?

Assertion $(A)$: Botanical gardens and zoological parks are $ex-situ$ conservation approaches.
Reason $(R)$: Botanical gardens and zoological parks are located within museums.
Which option is correct for Assertion $(A)$ and Reason $(R)$?

The world-famous botanical garden is located at:

The contrasting characteristics generally in a pair used for identification of animals in a Taxonomic Key are referred to as: