Target Exam

CUET

Subject

Biology

Chapter

Organisms and Populations

Question:

The number of individuals in the reproductive age group is more than the number of individuals in the pre- reproductive age group, the shape of its age pyramid would reflect the growth status of the population as:

Options:

Expanding

Stable

Declining

Homeostasis

Correct Answer:

Declining

Explanation:

The correct answer is Option (3) → Declining

A population at any given time is composed of individuals of different ages. If the age distribution (per cent individuals of a given age or age group) is plotted for the population, the resulting structure is called an age pyramid.

The shapes of age pyramids can be classified as follows:

  • Triangular-shaped age pyramids indicate a high number of pre-reproductive individuals, a moderate number of reproductive individuals, and even fewer post-reproductive individuals. This type of population is anticipated to grow or expand.
  • Bell-shaped age pyramids occur when pre-reproductive and reproductive individuals are nearly equal in numbers or percentages, with relatively fewer post-reproductive individuals. This population is expected to remain stable.
  • Urn-shaped age pyramids exhibit low numbers or percentages of pre-reproductive individuals, a maximum number of individuals in the reproductive age group, and a small number of individuals in the post-reproductive age group. Such a population is considered to decline.