Q. What are the Keys for Identifying plants and animals?

Keys are determined as devices to help in identifying plants and animals. These are merely an aid to identification based on successive choice between two contrasting characters. In plants keys are a part of floras or monographs given before the description of taxa and comprise of statements in a couplet which serve as lead. Lead are numbered and these begin from the same word in a couplet using prominent contrasting characters and are also referred to as diagnostic characters or key characters. The first contrasting characters in each couplet are referred to as primary key characters or lead characters followed by secondary key characters.