When the per capita birth rate equals the per capita death rate, __________.

• A. a population grows rapidly
• B. density-dependent limiting factors do not affect the population
• C. a population is in danger of extinction
• D. a population goes through up and down cycles
• E. the size of a population remains constant

Answer: (E)

Verified step by step guidance

1. Understand the concept of per capita birth rate and per capita death rate. The per capita birth rate is the average number of births per individual in a population over a specific time period, while the per capita death rate is the average number of deaths per individual in the same time period.
2. Recognize that when the per capita birth rate equals the per capita death rate, the number of individuals being born is equal to the number of individuals dying.
3. Consider the implications of equal birth and death rates on population size. Since births and deaths are balanced, there is no net change in the number of individuals in the population.
4. Relate this balance to the concept of population stability. A population with equal birth and death rates is said to be in a state of equilibrium, meaning its size remains constant over time.
5. Conclude that when the per capita birth rate equals the per capita death rate, the size of the population remains constant, as there is no increase or decrease in the total number of individuals.