Which of the following describes density-independent factors?

• A. Limiting factors that affect all populations in similar ways, regardless of population size.
• B. Factors that affect populations only at high densities.
• C. Factors influenced by predator–prey interactions.
• D. Factors related to competition among individuals of the same species.

Answer: (A)

Density-independent factors are factors that limit a population regardless of how many individuals are present. They are typically abiotic forces such as extreme weather, drought, floods, temperature extremes, or habitat destruction—events that affect small and large populations alike because their impact isn’t tied to population size. That’s why the description that limiting factors affect all populations in similar ways, no matter how big or small the population is, is the correct one. In contrast, factors like competition for resources, disease spread, and predator pressure often depend on how many individuals there are, increasing or changing their impact as density changes.