The figure below shows population cycles of snowshoe hare and lynx. recent field studies suggest that the most likely explanation for these cycles is
(a)periodic winter storms.
(b)predation of snowshoe hares by a combination of lynxes, foxes, and owls.
(c)nearly unlimited food for hares during the summers.
(d)boom and bust cycles in lemming populations.
(e)excessive predation of snowshoe hares by lynxes.

b is the best answer for this question.

"1. it should be, it has been for about 20 years, and it's really not much different in the end than breeding animals to have particular traits. there are always concerns about genetically engineered animals/plants affecting the environment in unexpected negative ways, but i can't think of an example where the fears didn't turn out to be baseless.  

first, as you point out, it would be a great advance in pharmacology, to be able to tailor drugs and their doses to me. the pros involve better medical treatment. the cons involve privacy issues like insurance companies denying coverage to people with genetic risk factors. looking at dna markers wouldn't affect the frequency of genetic diseases, but it would allow detection of them earlier. and ok, actually i suppose that if people used this information to avoid having children with genetic diseases, some might decrease in frequency."