In the logistic growth model, what happens to the growth rate as population size nears carrying capacity?

• A. It increases rapidly.
• B. It slows and approaches zero.
• C. It remains constant.
• D. It becomes unpredictable.

Answer: (B)

In logistic growth, limited resources create a ceiling on how fast a population can grow. As the population size gets close to the carrying capacity, competition for food, space, and other essentials intensifies, reducing the number of new individuals that can be added each generation. In the standard logistic equation dN/dt = rN(1 − N/K), the factor (1 − N/K) declines toward zero as N approaches K. This means the overall growth rate (the rate of change in population size) drops toward zero, and births balance deaths. So the growth rate slows and effectively stops at carrying capacity.