Question

Study the age pyramids given below and select the correct statement regarding these.

A. A is a triangular age pyramid where the pre reproductive stage is very large as compared to the reproductive and post reproductive stages of the population.This type of age structure indicates that the population would increase rapidly.
B. B is an inverted bell shaped age pyramid where no. of pre reproductive and reproductive individuals is almost equal. This type of age pyramid indicates that the population is stable.
C. C is an urn shaped age pyramid where more no. of reproductive individuals are present. This type of age structure indicates that the population is declining.
D. All of the above

Answer 1

Age pyramid is also called population pyramid. The distribution is based on different characteristics like pre-reproductive, reproductive and post reproductive and the figure obtained is in the pyramid form.

Complete answer:
Population pyramid or age-gender pyramid is the graphical representation depicting the distribution of different age group persons in a population.
There are three different age pyramids A, B, C which tells the different growth rate of the population.
A. According to Figure A (triangular age pyramid) there is a large pre-reproductive stage, moderate number of reproductive stages and small number of post-reproductive stages. It means that the population is rapidly growing or there is a young population present. So, the statement above is correct. B. According to Figure B (inverted bell shaped age pyramid) pre-reproductive and reproductive stage is stable as both the stages present are equal. So the stable population is seen. The statement above is correct.
C. According to Figure C (urn shaped age pyramid) the post-reproductive stage is large whereas the reproductive stage goes from moderate to low and pre-reproductive is decreasing. Hence the population is declining or there is an older population present. The statement above is correct. So all the three statements mentioned here are correct.

Hence, the correct answer is option (D).

Additional information:
Rapidly or expanding population pyramids are found where there are high birth rates and low life expectancy. The population is fast growing and the population contains wide younger ages. Stationary population pyramid occurs when the death rate of the population is equal to the birth rate. Declining population pyramid is narrow at last with the older population because there is low death and birth.

Note: A pyramid helps in knowing the age of a population. In ecology it is helpful in knowing the overall population distribution. Every country has a population pyramid which depends on education, health care facilities and economics.