What term denotes the maximum population size that an environment can sustain indefinitely?

• A. Birth rate
• B. Death rate
• C. Carrying capacity
• D. Growth rate

Answer: (C)

Carrying capacity is the maximum population size an environment can support indefinitely. It reflects how much food, water, space, and other resources are available and how these limits determine how many individuals can live there over the long term without causing lasting damage to the habitat.

In population dynamics, growth slows as resources become limiting: when a population is small, it can grow rapidly, but as it approaches the carrying capacity, the rate of increase drops toward zero because births balance deaths and competition for resources intensifies. If the population overshoots this limit, resources can become depleted or the habitat degraded, causing the carrying capacity to drop or the population to crash.

Birth rate and death rate describe how many individuals are produced or die over time, but they don’t specify the sustainable limit of the population. Growth rate is the overall change in population size, which is driven by those birth and death rates but isn’t itself the maximum sustainable size.