Explain about the usage of key as a taxonomic aid.

Key:

Keys are based on the contrasting characters generally in a pair called Couplet.

While comparing similarities or dissimilarities from the couplet, one option is either rejected or accepted or visa versa.

Each statement in a key is called a lead.

There are separate keys for each taxonomic category i.e. species, genus, family, order, etc.

Key is generally analytical and authentic.