The maximum population size that an environment can support over time is called ...

• A. Carrying capacity
• B. Gene pool
• C. Population density
• D. Logistic growth

Answer: (A)

Carrying capacity is the maximum population size an environment can support indefinitely. It depends on the availability of resources like food, water, shelter, and space, as well as factors such as competition, predation, disease, and waste buildup. When a population grows toward this limit, growth slows and eventually levels off because resources become limiting and density-dependent factors increasingly curb reproduction and survival. This concept can change over time as conditions change; for example, more plentiful resources or better habitat can raise carrying capacity, while harsher conditions or higher predation can lower it. It is different from population density, which is simply how many individuals occupy a given area, and from logistic growth, which describes the S-shaped growth pattern as a population approaches carrying capacity. The gene pool refers to the genetic variation within the population, not its maximum sustainable size.