Describe Key as a taxonomical aid.

(N/A) $\rightarrow$ Key is a taxonomical aid used for the identification of plants and animals based on similarities and dissimilarities.
$\rightarrow$ The keys are based on contrasting characters,generally in a pair called a couplet.
$\rightarrow$ It represents the choice made between two opposite options.
$\rightarrow$ This results in the acceptance of only one and the rejection of the other.
$\rightarrow$ Each statement in the key is called a lead.
$\rightarrow$ Separate taxonomic keys are required for each taxonomic category,such as family,genus,and species,for identification purposes.
$\rightarrow$ Keys are generally analytical in nature.