AP BIOLOGY

Detailed explanation-1: -The single most important factor in population growth is the total fertility rate (TFR). If, on average, women give birth to 2.1 children and these children survive to the age of 15, any given woman will have replaced herself and her partner upon death. A TFR of 2.1 is known as the replacement rate.

Detailed explanation-2: -If there are comparatively more young adults than older adults where mortality is highest, then even at replacement fertility levels (when each woman has about an average of two children) there will be more births than deaths.

Detailed explanation-3: -Population growth rate is affected by birth rates, death rates, immigration, and emigration. If a population is given unlimited amounts of food, moisture, and oxygen, and other environmental factors, it will show exponential growth.

Detailed explanation-4: -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. Populations grow or shrink depending on if they gain people faster than they lose them.

Detailed explanation-5: -There remain to be high fertility rates in India because the poor peoples’ livelihood thrives from agriculture. Many poor people consider it necessary to have many children because they are considered their parents’ insurance and the greater number of children increases the wealth of the family due to child labor.