Big losses of genetic variation for the small populations are readily caused by

MRCORRECT has answered the question

Explanation:

Genetic drift can cause big losses of genetic variation for small populations. Populationbottlenecks occur when a population's size is reduced for at least one generation. describes changes in population genetics in which extreme values for a trait are favored over intermediate values

a. decomposes use carbon from dead organisms as fuel for cellular respiration, returning carbon dioxide back into the atmosphere.

this is true, assuming that the allele is completely recessive and incomplete dominance is not a factor.