A population pyramid with a broad base, narrow apex, and concave sides is characteristic of which demographic pattern?
- A Stationary population with low birth rate and low death rate
- B Rapidly growing population with high birth rate and falling death rate ✓
- C Declining population with very low birth rate
- D Ageing population with inverted pyramid
Correct answer: B. Rapidly growing population with high birth rate and falling death rate
Explanation
A broad-based, narrow-apex pyramid with concave (inward-curving) sides is the 'expansive' or 'progressive' type, typical of developing nations with high birth rates, falling death rates, and rapidly growing populations. The broad base reflects many young people (high birth rate), and the concave sides reflect high early-age mortality before old age is reached. This is the current pattern seen in many sub-Saharan African countries.
Reference: Park's Textbook of Preventive and Social Medicine, 27th ed.
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