Question

Which one of the statements correctly correlates with the diagrams?

1) A) and B) are steady population
2) A) and D) are declining population
3) C) and D) are growing population
4) B) and D) are declining populations.

Answer 1

Hint:The biological definition of population is the total number of organisms that belong to the same group or species and occupy the same geographical area and are also capable of interbreeding among themselves.

Complete answer:
Different individuals in a population belong to different age groups. The natality and mortality of a population is defined by the number of old and young members residing in that particular population. Age structure is the term that is used to define the proportion of individuals in each age group. Age structure also influences the nature and characteristics of a specific population. Any given population can be divided into three distinct age classes- pre-reproductive, reproductive, post-reproductive ages. The duration of these classes varies greatly among different organisms. The age distribution is represented with the help of age pyramid, which gives an idea about the number or proportion of individuals belonging to different age classes in a population at any given point of time. Pre-reproductive age involves a rapidly growing population with a high birth rate. Reproductive age is one where individuals are capable of reproducing and producing offspring. Post-reproductive age is the one which comprises mostly of elderly individuals.
Hence the correct answer is option (2) i.e, (A) and D) are declining populations.


Note: Thus the age pyramid serves as an important graphical representation that helps us to get an idea about the different age groups of individuals that are present in a given population by which we can track whether it is a growing, declining or steady population.