Which term best describes a population whose size stays about the same because births equal deaths?

Which term best describes a population whose size stays about the same because births equal deaths?

• A. Exponential growth
• B. Plateau
• C. Carrying capacity
• D. Decline

Answer: (B)

When births balance deaths, there is zero net growth in the population. That means the population size remains roughly constant over time, which on a graph appears as a flat line or plateau. The term plateau captures this steady state directly. Exponential growth would require births outpacing deaths, leading to a rising population. Decline means deaths exceed births, so the population decreases. Carrying capacity refers to the environmental limit on population size, not the actual pattern of stability itself—while a population at carrying capacity can be stable, the situation described is best described as a plateau, a stable, unchanging size.

When births balance deaths, there is zero net growth in the population. That means the population size remains roughly constant over time, which on a graph appears as a flat line or plateau. The term plateau captures this steady state directly.

Exponential growth would require births outpacing deaths, leading to a rising population. Decline means deaths exceed births, so the population decreases. Carrying capacity refers to the environmental limit on population size, not the actual pattern of stability itself—while a population at carrying capacity can be stable, the situation described is best described as a plateau, a stable, unchanging size.