AP BIOLOGY

Detailed explanation-1: -Immigration describes individuals moving into the population while emigration describes individuals exiting the population. If immigration rates are higher than emigration rates, the population increases, whereas if emigration rates are higher than immigration rates, the population size decreases.

Detailed explanation-2: -Populations gain individuals through births and immigration. They lose individuals through deaths and emigration. These factors together determine how fast a population grows.

Detailed explanation-3: -Similarly, migration will reduce ageing in affluent regions and increase it in poor ones. Most countries and regions experiencing population decrease do so mainly due to natural change (the difference between births and deaths), while regions which gain population do so mainly due to extra-Europe migration.

Detailed explanation-4: -From the above statement, it is clear that if the number of immigration and births is more than emigration and death, the rate of population increases and attains full potential rate.