- (A) Increasing population size reduces available resources, thus limiting
population growth. In restricting population growth, a density-dependent
factor intensifies as the population size increases, affecting each individual
more strongly. Population growth declines because of death rate increase,
birth rate decrease, or both. There is a reduction in the food supply, which
restricts reproduction resulting in less offspring. The competition for space
to establish territories is a behavioral mechanism that may restrict
population growth. Predators concentrate in areas where there is a high
concentration of prey. As long as the natural resources are available in
sufficient quantity, the population will remain constant. As the population
decreases, so do predators. The accumulation of toxic wastes may also limit
the size of a population. Intrinsic factors may play a role in limiting a
population size. High densities may cause stress syndromes, resulting in
hormonal changes that may delay the onset of reproduction. It has also been
reported that immune disorders are related to stress in high densely
populated areas. Density-independent factors include weather, climate, and
natural disasters such as freezes, seasonal changes, hurricanes, and fires.
These factors affect all individuals in the population, regardless of
population size.
marvins-underground-k-12
(Marvins-Underground-K-12)
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