Final answer:
Density-independent factors impact population sizes regardless of population density and include factors like weather and natural disasters. Density-dependent factors like disease and predation increase in intensity with population density.
Step-by-step explanation:
A density-independent factor affects the size of a population regardless of the population's density. This means that whether there are many or few individuals in a population, the factor will have the same effect. Common examples of density-independent factors include environmental stresses such as weather events, natural disasters, and pollution. For instance, extreme weather conditions like a severe drought or a harsh winter can cause the same proportion of deaths in a population, no matter how many organisms are in that population. In contrast, density-dependent factors such as predation, disease, and competition often intensify as the population density increases.