NEET BIOLOGY

Detailed explanation-1: -There are three components of change: births, deaths, and migration. The change in the population from births and deaths is often combined and referred to as natural increase or natural change.

Detailed explanation-2: -The change in the population size of a country during a specific period of time is called Population growth. The growth of population in a region depends upon fertility, mortality and migration. Fertility or the birth rate is measured in terms of total number of live births per thousand population per year.

Detailed explanation-3: -Population growth rate (r) is how fast a population changes in size over time. A positive growth rate means a population is increasing. A negative growth rate means it is decreasing. The two main factors affecting population growth are the birth rate (b) and death rate (d).

Detailed explanation-4: -Overall, population grows or shrinks through two very basic components: natural change (births minus deaths) and migration (domestic plus international).