Question

Define population growth. Explain different types of age pyramids.

Answer 1

Definition: The increase in the size of a population or increase in number of individuals is known as population growth. When resources in the habitat are unlimited, population show exponential growth. When resources in the habitat are limited, it leads to competition between individuals for limited resources. This type of population growth is called logistic growth

Age distribution and Age pyramids:

1. A population consists of individuals with different ages. The entire population is divided into three age groups - prereproductive (0-14 years), reproductive (age 15-44 years), post reproductive (45-85+years)The relative proportion of individuals of various age groups in the population is referred to as age structure of the population.
2. If the age distribution (per cent individuals of a given age or age group) is plotted for the population, the resulting structure is called as age pyramid.