What are age pyramids? Draw and explain the age pyramids of expanding, stable and declining populations.
How to lay out the answer. Follow the frame, then write it in your own words.
1 · Define in one line. An age pyramid is a diagram of the number of individuals in each age group of a population, males on one side and females on the other.
2 · Name the age groups. Pre-reproductive, reproductive and post-reproductive, from the base to the top.
3 · Draw the three pyramids. [Diagrams: (a) Expanding, triangular; (b) Stable, bell-shaped; (c) Declining, urn-shaped; label the age groups, males and females]
4 · Explain each shape.
Expanding: broad base, many young, population growing.
Stable: young about equal to reproductive adults, size steady.
Declining: narrow base, fewer young, population shrinking.
5 · Link to real life. Governments read age pyramids to plan schools, jobs and care for the elderly.
6 · Close in one line. So the shape of an age pyramid tells the growth status of a population.
Scoring tip: Three neat labelled pyramids earn most of the marks. Write the shape word (triangular, bell, urn) under each.
