Which term describes the point at which population size levels off due to limiting factors?

• A. Carrying capacity
• B. Mutation
• C. Fossil
• D. Inheritable traits

Answer: (A)

Carrying capacity is the largest number of individuals of a species that a given environment can support over the long term with the available resources. As a population grows, resources like food, water, and space become limited, and factors such as predation and disease keep the growth from continuing unchecked. When births and deaths balance out due to these limiting factors, the population levels off at a stable size—the carrying capacity. This idea fits the typical logistic growth pattern, where a rapid early increase slows and then plateaus as resources constrain further growth. Remember, carrying capacity can change if the environment changes (more resources or new conditions can raise it).

The other terms don’t describe this idea: mutation is a genetic change, fossils are preserved remains from the past, and inheritable traits are genetic features passed to offspring.