Question

The following graphs represent age pyramids of a population.

• A. A - stable, B - expanding, C - declining
• B. A - expanding, B - stable, C - declining
• C. A - stable, B - declining, C - expanding
• D. A - declining, B - stable, C - expanding

Hint:

Look solely at the bottom block (children) versus the middle block (parents).
Bottom = Middle $\rightarrow$ Stable.
Bottom < Middle $\rightarrow$ Declining.
Bottom > Middle $\rightarrow$ Expanding.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept: Age pyramids graphically depict the age distribution within a population. The shape of the pyramid indicates whether the population is growing, stable, or shrinking.
Step 2: Key Formula or Approach: Analyze the width of the bottom tier (pre-reproductive age group) relative to the middle tier (reproductive age group) for each pyramid.
Step 3: Detailed Explanation:
In Pyramid A, the base (pre-reproductive individuals) is roughly equal in width to the tier above it (reproductive individuals). This bell-shaped structure indicates zero growth, meaning the population is stable.
In Pyramid B, the base is distinctly narrower than the middle reproductive section. This urn-shaped structure indicates that fewer offspring are being produced than are needed to replace the current generation, meaning the population is declining.
In Pyramid C, the base is very broad and significantly wider than the reproductive tier. This typical pyramid shape indicates a high birth rate and a rapidly expanding population.
Matching these shapes to their statuses gives: A - stable, B - declining, C - expanding.
Step 4: Final Answer: The correct option is (3).