Which of the following is a density-dependent limiting factor?

• A. A flood.
• B. A natural disaster.
• C. Competition for food.
• D. Temperature change due to seasonal shift.

Answer: (C)

Density-dependent limiting factors are factors whose impact grows as the population gets larger. When more organisms are sharing the same space and resources, competition for food increases, making it harder for individuals to get enough to survive and reproduce. That’s why competition for food best fits here: as population density rises, the resource becomes more scarce per individual, directly limiting growth and survival.

Floods and natural disasters don’t depend on how many organisms are present, so they’re density-independent—they can affect a population regardless of its size. Seasonal temperature changes are similarly density-independent, since they are environmental conditions that affect all individuals rather than being scaled by population density.