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 Problem:
An age pyramid is a graphical illustration that shows the distribution of various age groups (pre-reproductive, reproductive, and post-reproductive) in a population.
Step 2: Approach and Formula:
Analyze the relative width of the pre-reproductive base compared to the reproductive middle to determine the population's growth trajectory.
Step 3: Detailed Explanation:
Based on standard ecological age pyramids:
- Pyramid A (Triangular shape): The base (pre-reproductive group) is very broad and significantly larger than the reproductive group. This indicates a high birth rate and a rapidly expanding population.
- Pyramid B (Bell shape): The base and the middle sections are almost equal in width. This indicates that the pre-reproductive and reproductive age groups are roughly equal, meaning the population size remains constant or stable.
- Pyramid C (Urn shape): The base is notably narrower than the reproductive middle section. This indicates fewer births and an aging population, meaning the population is declining.
Thus, A is expanding, B is stable, and C is declining.
Step 4: Final Answer:
The correct option is (2).