Question

A student of taxonomy was puzzled when told by his professor to look for a key to identify a plant. He went to his friend to clarify what ‘key’ the professor was referring to? What would the friend explain to him?

Answer 1

A taxon is a biological classification unit which is used in Science or Taxonomy. The plural of taxon is taxa. They are organized in a hierarchy. Taxonomy is the branch of science that is involved in the classification of organisms. There are different types of taxonomy like alpha taxonomy, evolutionary taxonomy, etc.

Complete Answer:
A key is a very important tool that is used to study taxonomic categories. A key has two characters that are in contrast to each other. These characters usually happen in pairs and these pairs are known as couplets. When a key is being studied, either of the contrasting characters is accepted or rejected. Each of the statements in a key is known as a lead. A key is normally analytical in nature. Also, each taxonomic category requires that a different key be used. Keys play an important role by helping in the step-by-step identification of a particular organism. An example for this is checking for the presence or absence of a notochord, which gives a clue whether the organism belongs to the subphylum Vertebrata or Invertebrata. Another example is the presence or absence of lungs which helps in classifying the organism into groups Tetrapoda or Pisces.

Note:
The design of a taxonomic key is in such a way that it begins with observing the large and prominent features which help in dividing the organisms into a few large groups. Then the next set of couplets help in dividing them into smaller groups which use smaller details to help the user.