In a population pyramid, what does the Y-axis represent?

In a population pyramid, what does the Y-axis represent?

• A. Year
• B. Age of population
• C. Population density
• D. Amount of population

Answer: (B)

Understanding age structure is the key here. In a population pyramid, the vertical axis lists age groups (like 0–4, 5–9, 10–14, and so on). That means the Y-axis represents the age of the population. The horizontal axis shows how many people are in each age group, often split by gender on each side. This arrangement lets you quickly see whether there are more young people or more older people in the population. The other options don’t fit because time (year) isn’t what the axis displays, population density isn’t the measured dimension on this axis, and the actual population size is shown by the widths of the bars, not by the vertical axis.

Understanding age structure is the key here. In a population pyramid, the vertical axis lists age groups (like 0–4, 5–9, 10–14, and so on). That means the Y-axis represents the age of the population. The horizontal axis shows how many people are in each age group, often split by gender on each side. This arrangement lets you quickly see whether there are more young people or more older people in the population. The other options don’t fit because time (year) isn’t what the axis displays, population density isn’t the measured dimension on this axis, and the actual population size is shown by the widths of the bars, not by the vertical axis.