Question

What is the role of keys in taxonomy ? Illustrate with example.

Answer 1

A key is a scheme for identificaion of animals and ji plants which is based on contrasting characters. Taxonomic keys are useful in identification of unknown organisms.

They are analytical in nature. They are of two types :

(a) Yoked or Indented key, (b) Bracketed key.

(a) Indented key: It gives sequence of choice between two or more characters of species. Correct choice is essential for identification. Take the example of family Ranuculaceae. Indented key is used to identify the genera in the family Ranunculaceae by considering the characters of the carpel and fruit of the specimens. The first choice begins with carpel with single ovule and achene type of fruit to contract to carpels being many ovuled and fruits are follicles.

Answer 2

Taxonomic keys are written characteristic information that helps a person to identify an unknown species of living organism. The taxonomic key provides a certain structure on the basis of which the user can sort out the taxonomic position of the unknown species.

Indented key provides number of choices between two or more contrasting characters.

For example,

Able to disappear
Wings absent
Body covered by furs
Wings present
Unable to disappear
Body covered by feathers
In Bracketed key the two or more contrasting characters always remain in pairs.

For example,

Able to disappear
Unable to disappear

Wings present
Wings absent