Q.Why are living organisms classified?

Living organisms are classified because they exist in an enormous variety — between roughly 1.7 and 1.8 million kinds have already been described, and many more remain unknown. Studying each of these millions of organisms one by one is simply impossible, so we place them into convenient groups based on easily observable characters.

Classification helps us in several ways:

• It makes the study of such a huge number of organisms manageable.
• It lets us recognise similarities and differences between organisms.
• It groups related forms together, so knowing one member tells us a good deal about the rest.
• It gives every organism a definite, orderly place, which makes communication and further study easier.

Wherever we look, life appears in astonishing variety — plants, insects, birds, animals and countless organisms too small to see. The more ground our observations cover, the wider the range of living things we meet. Scientists have so far recognised and described somewhere between 1.7 and 1.8 million distinct kinds, or species, and many others are still unknown. Faced with such richness, a natural question arises: how can anyone possibly study all of them?

The answer is that we do not study them one at a time. Instead we group them. Placing organisms into convenient categories on the basis of easily observable characters is called classification. When we use a word like "dog", "insect", "mammal" or "plant", each term immediately brings to mind a whole set of associated features — and that is exactly what a group does for us.

Classification serves us in important ways:

• It makes study possible. Millions of organisms cannot be examined individually, but a manageable number of groups can.
• It reveals relationships. Sorting organisms by their characters brings out the similarities they share and the differences that set them apart.
• It is efficient. Once related organisms are grouped, knowing the features of the group tells us a great deal about any member of it.
• It gives order. Every organism gains a definite position in an organised scheme, which makes description, naming and communication far clearer.