Age Pyramid

An age pyramid, also known as an age distribution graph or population pyramid, is a graphical representation of the age and sex distribution of a population. The pyramid is divided into male and female populations, with age cohorts represented on the horizontal axis and the percentage of the population represented on the vertical axis.

Interpreting an Age Pyramid

The shape of an age pyramid provides valuable insights into the demographic characteristics of a population. By examining the width of the base and the narrowness of the top, we can determine the growth rate and age structure of the population.

Wide Base

A wide base on an age pyramid indicates a large proportion of young individuals in the population. This suggests a high birth rate and a growing population. The wider the base, the higher the number of children and young adults, indicating a significant proportion of the population is in the reproductive age group.

Narrow Top

A narrow top on an age pyramid indicates a smaller proportion of elderly individuals in the population. This suggests a lower life expectancy and a lower proportion of older adults. A narrow top indicates a lower percentage of the population in the older age groups.

Explanation of the Correct Answer

The correct answer, option 'D' (Growing rapidly), is inferred from the description of an age pyramid with a wide base and narrow top. This pyramid shape indicates a population that has a high birth rate and a large proportion of young individuals. The narrower top suggests a lower life expectancy and a smaller proportion of older individuals.

When a population has a wide base and a narrow top, it indicates that the birth rate is higher than the death rate, leading to a rapid increase in population size. The large number of young individuals suggests a growing population with a high potential for future growth.

Therefore, an age pyramid with a wide base and narrow top indicates a population that is growing rapidly.