Think about what the terms density-dependent and density-independent mean. Which of the following statements about how density-dependent and density-independent factors affect population growth is TRUE? a. The effect of most density-independent factors on population growth is greater when population density is high.
b. The effect of most density-independent factors on population growth is greater when population density is low. Number of Sheep (Thousands)
c. The effect of most density-independent factors on population growth is not related to population density.
d. The effect of most density-dependent factors on population growth is not related to population density.

The Correct answer is C: The effect of most density-independent factors on population growth is not related to population density.

Explanation:

In nature, the population size and growth are limited by many factors. Some of these factors depend on the population density, while some others are density-independent.

Limiting density-dependent factors provoke a change in the population growth rate per capita, as the density increases.  In general, this change is a decrease in the growth rate. An example of these density-dependent factors might be competition or limited food availability.

The density-independent factors also affect the growth rate in a population, but they do not depend on its density. Some examples of these are natural disasters, or environmental conditions, among others.  

So,

a) False: the effect of most density-independent factors do not depend on the population density.

b) False: the effect of most density-independent factors do not depend on the population density.

c) TRUE: The effect of density-independent factors are not related to population density

d) False: The effect of most density-dependent factors ARE related to population density