Question

Read the following statements (I-III) and choose the correct option
I. Sex ratio indicates future breeding potential of a population
II. Equal or a nearly equal population of males and females indicates healthy sex ratio
III. In most sexually reproducing species (in the absence of interference), the sex ratio tends to be 1 : 1

• A. Statements (I) and (II) are true, but statement (III) is false
• B. Statements (I) and (II) are false, but statement (III) is true
• C. Statements (I) and (III) are true, but statement (II) is false
• D. All statements are true

Answer 1

The correct option is D All statements are true

A population is a group of individuals of the same species living in a particular geographical area and capable of potentially interbreeding with each other to produce fertile offspring.

An individual in a population can be biologically born as a female or male and based on the sex of the organism, the population can be divided into male population and female population. The ratio of male to female population of an area is called sex ratio.

It is one of the important attributes calculated under the human population census. It can be calculated as the ratio of the total number of male individuals to the total number of female individuals in a given population of any region multiplied by 100.

Sex ratio indicates future breeding potential of a population. Breeding potential refers to the maximum rate of increase in the number of individuals of a population under optimum conditions. If in a population sex ratio is disturbed or the females are less compared to males then it will certainly decrease the number of pre-reproductive individuals in the future generations. This will cause a decline in the population. Hence, statement I is correct.

The population survives and continues to exist when the individuals in the population interbreed. Hence, an equal or a nearly equal population of males and females is very important and it indicates a healthy sex ratio.
Hence, statement II is correct.

In any normal situation (in the absence of interference), in most sexually reproducing species, the sex ratio usually tends to be 1: 1. The production of males and females in a ratio of 1: 1 is generally the most common evolutionary strategy of organisms.
Hence, statement III is correct.

While enumerating human population, from social perspective, sex ratio is an important social indicator to measure the extent of equality between males and females in a society at a given time.