the term "biodiversty" has been derived from 'bio' and 'diversity'."Diversity" means variety within a species and among species.Biodiversity is a measure of the variety of organisms present in different ecosystem.
Diversity of plants and animals
the diversity of plants '(flora) and animals'(fauna)' ia region depends on climate,altitude,soils and the presence of other species.it is the richest in the tropics.
biodiversity found on earth today is the result of 4billion years of evolution.the origon of lifeis not well known to science, though limited evidencs suggests that until 600million years ago, all life consisted of bacteria and similar unicellular organisms.
IMPORTANCE OF BIODIVERSITY
Biodiversity provides food for humans. A significiant proportion of drugs are derived ,directly or indirectly , from biological sources. a wide range of industrial materials e.g.building materials, fibres,dyes,resins,gums,adhesives, rubber and oilare derived directly from plants.Biodiversity plays important role in making and maintaining ecosystem.Biodiversity is directly involved in recycling nutrients and providing fertile soils.
CLASSIFICATION -AIMS AND PRINCIPLES
There is a large collection of very dissimilar form of organisms, found on earth .over 1.5 million types of animals and over 0.5 million types of plants are known to biologists and these are only a small percentage of the total types estimated to live on earth.To classify them into different groups biologists divide organisms into groups and subgroups.
AIMS OF CLASSIFICATION
The branch of biology which deals with classification is called TAXONOMY and the branch which deals with classification and also traces the evolutionary history of organisms is known as SYSTEMATIC.the main aims of both these branches are;
no 1=to determine similarities and differences among organisms so that they can be studied easily.
no 2=to find the evolutionary relationship among organisms.