How are density-dependent factors defined?

Density-dependent factors are defined as limited resources that become depleted due to large population sizes. These factors have a greater impact on the population as its density increases, meaning that as the number of individuals in a given area rises, the effects of these factors become more pronounced. Examples of density-dependent factors include food availability, water supply, habitat space, and disease, all of which can lead to increased competition among individuals in a crowded environment.

When population size grows, the demand for these limited resources increases, which can lead to a decrease in individual health, reproductive success, or survival rates. This mechanism helps to regulate population growth by increasing mortality rates or decreasing birth rates as resources become scarce. Therefore, the correct answer emphasizes the relationship between population density and the availability of resources, illustrating how increased competition can influence population dynamics.