How have human activities caused desertification ? Explain.

The main causative factor of desertification is

Human papiloma virus cause

Human papilloma virus causes

How human activities increased the supply of fixed nitrogen available to the primary producers?

Assertion (A): Wildlife should be conserved. Reason (R): Human activities cause several plants and animals to extinct.

Water polluted by various human activities causes a number of water borne diseases. Which of the following is not a water borne disease?

Phocomelia in humans is caused by