Physical, chemical and biological factors affecting the living organisms in any possible way is collectively called as environment. In short, environment is the condition in surrounding. 37

The science that deals with the study of interactions between biotic and abiotic factors of the environment is called as ecology. 38

Basic functional unit used to study the ecology is called as ecosystem. 38

Biodiversity is the richness of living organisms in nature due to presence of varieties of organisms, ecosystems and genetic variations within a species. 42