Disease restriction to particular area or population is

The plant or animal species found restricted to a particular area (zone), region or country is called

In a population of an area, the difference in the natality rate and mortality rate is zero in a particular year, but the population density has decreased. Which of the following may be the reason for this decrease ?

In a population of an area, the difference in the natality rate and mortality rate is zero in a particular year, but the population density has decreased. Which of the following may be the reason for this decrease ?

The biotic face which restricts the natural populations size

A species restricted to a given area is

A species restricted to a given area is