Which situation is an example of a density-independent limiting effect?
A) The killing of seedlings by drought
B) A limited food supply due to competition
C) A limit of nesting space in an area to 70 nests
D) The tendency of aggregations of guppies to attract predators
E) An increase in the incidence of malaria as populations increase

Question

Quizplus · Accepted Answer

A drought affecting seedlings is an example of a density-independent limiting effect because it is not affected by the density of the population. Regardless of how many seedlings there are, a drought will limit their survival.

B is incorrect, as competition for resources is a density-dependent limiting effect since it is affected by the density of the population.

C is also incorrect since the limitation of nesting space is a density-dependent effect that affects the population as it grows.

D is a density-dependent effect since the aggregation of guppies attracts predators as the density of guppies increases.

E is a density-dependent effect because an increase in population density would lead to more individuals being exposed to the malaria parasite, rather than a direct environmental factor that would limit population growth regardless of the density of individuals.

Which Situation Is an Example of a Density-Independent Limiting Effect