The greatest problem of water conservation is to reduce the amount of

Association of animals in which both the partners are benefitted is called

A permanent loss to a population is due to

Population was termed as self- perpetuating unit by

The association between Rhizobium and roots of leguminous plants is

The study of interactions between living organisms and environment is called as

Reduction in vascular tissue, mechanical tissue and cuticle is characteristic of

Niche is defined as the

Human population exhibits

Water holding capacity is maximum in case of