Which term defines the maximum population size that an environment can sustain indefinitely?

• A. Population growth rate
• B. Carrying capacity
• C. Biodiversity threshold
• D. Extinction probability

Answer: (B)

Carrying capacity describes the maximum population size an environment can sustain indefinitely. It reflects the balance between resources like food, water, and shelter and the demands of the population, including competition, predation, and disease. When a population approaches this limit, growth slows and stabilizes as resources become limiting. This concept also accounts for changes over time: improvements in resources or technology can raise carrying capacity, while habitat loss or depletion can lower it. In contrast, population growth rate is about how fast the population changes, biodiversity threshold isn’t a standard term for maximum population size, and extinction probability concerns the risk of disappearing rather than the sustainable limit of a population.