Which statement describes a density-dependent factor?

Which statement describes a density-dependent factor?

• A. Food availability decreases as population grows.
• B. Temperature changes with the seasons.
• C. A storm occurs randomly.
• D. A drought occurs occasionally.

Answer: (A)

Density-dependent factors are those whose impact on a population grows as the number of individuals increases. The idea is that when more organisms are competing for the same limited resources, each individual gets less, which can slow growth, reduce reproduction, or increase mortality as population size rises. The statement that food availability decreases as the population grows fits this pattern perfectly because the effect (less food per person) becomes more pronounced with more people sharing the same resource. In contrast, the other statements describe events that don't depend on how many organisms are present. Temperature changes with the seasons are a predictable environmental pattern; storms occur randomly and affect everyone more or less equally; droughts are climate events that can impact populations regardless of their size. Therefore, the food-availability relationship best illustrates a density-dependent factor.

Density-dependent factors are those whose impact on a population grows as the number of individuals increases. The idea is that when more organisms are competing for the same limited resources, each individual gets less, which can slow growth, reduce reproduction, or increase mortality as population size rises. The statement that food availability decreases as the population grows fits this pattern perfectly because the effect (less food per person) becomes more pronounced with more people sharing the same resource.

In contrast, the other statements describe events that don't depend on how many organisms are present. Temperature changes with the seasons are a predictable environmental pattern; storms occur randomly and affect everyone more or less equally; droughts are climate events that can impact populations regardless of their size. Therefore, the food-availability relationship best illustrates a density-dependent factor.