What does carrying capacity mean?

• A. The average age of individuals.
• B. The total area of habitat.
• C. The maximum population size that a habitat can support indefinitely given resources.
• D. The rate of depletion of resources.

Answer: (C)

Carrying capacity is the maximum population size a habitat can support indefinitely given the resources available. This limit comes from finite resources like food, water, space, and shelter, which constrain births and deaths and keep the population from growing without bound. As resources become scarce or environmental conditions change, this capacity can shift, so it’s a limit that applies under current conditions, not a fixed number. If a population grows beyond this limit, resources get depleted, and the population tends to decline back toward the carrying capacity.

The other ideas described—an average age of individuals, the total area of habitat, or the rate at which resources are used—are not what carrying capacity measures. The average age reflects demographics, the habitat area relates to space but not how many individuals can be sustained, and the depletion rate is a factor that affects carrying capacity but isn’t the definition of it.