Which statement describes logistic population growth?

Which statement describes logistic population growth?

• A. It levels off as carrying capacity is reached.
• B. It continues to rise exponentially with unlimited resources.
• C. It decreases to zero due to resource depletion.
• D. It fluctuates unpredictably around a fixed point.

Answer: (A)

Logistic growth describes a population that grows quickly when small but slows as resources become limiting, eventually leveling off at a carrying capacity. Carrying capacity is the maximum number the environment can support indefinitely given available resources like food, space, and water. As population size increases, competition intensifies and per-capita growth slows, so the overall growth rate drops until it balances out and the population stabilizes near that carrying capacity. This creates the characteristic S-shaped (sigmoidal) curve. The other scenarios don’t fit because logistic growth isn’t infinite or crashing. Exponential growth would occur only if resources were unlimited, which isn’t realistic. A crash to zero would require complete resource depletion without a stable supportive limit. Fluctuating around a fixed point implies irregular oscillations or external factors, whereas logistic growth predicts a smooth approach to a stable carrying capacity under constant conditions.

Logistic growth describes a population that grows quickly when small but slows as resources become limiting, eventually leveling off at a carrying capacity. Carrying capacity is the maximum number the environment can support indefinitely given available resources like food, space, and water. As population size increases, competition intensifies and per-capita growth slows, so the overall growth rate drops until it balances out and the population stabilizes near that carrying capacity. This creates the characteristic S-shaped (sigmoidal) curve.

The other scenarios don’t fit because logistic growth isn’t infinite or crashing. Exponential growth would occur only if resources were unlimited, which isn’t realistic. A crash to zero would require complete resource depletion without a stable supportive limit. Fluctuating around a fixed point implies irregular oscillations or external factors, whereas logistic growth predicts a smooth approach to a stable carrying capacity under constant conditions.