Which of the following statements best describes how limiting factors influence carrying capacity?

• A. They always increase the carrying capacity.
• B. They help set the upper limit on population size by constraining resources.
• C. They do not affect population size.
• D. They only apply to plants.

Answer: (B)

Limiting factors are the conditions or resources that prevent a population from growing indefinitely. Carrying capacity is the largest population that an environment can sustain over time given those resources. When resources like food, water, shelter, or space become limited, the population can’t keep increasing; growth slows and the numbers level off as births balance deaths. This upper limit on population size is set by the availability of resources, so limiting factors constrain rather than expand carrying capacity. They can affect populations of all organisms, not just plants, and they can act in ways that depend on population density or independent of it.