Which of the following is an example of a density-independent limiting factor?

• A. Competition for water.
• B. Predation.
• C. Disease.
• D. A severe frost that affects all individuals equally.

Answer: (D)

The key idea is how factors limit population growth based on population size. Density-independent factors affect the population regardless of how many individuals are present, and they are usually abiotic, like weather or climate events. A severe frost fits this because it harms all individuals equally, no matter how crowded the population is, so its impact doesn’t scale with density.

In contrast, competition for water, predation, and disease tend to change with how many organisms are in the population. More individuals mean more competition for resources, more opportunities for predators, and more hosts for disease, so those are density-dependent factors.