What characteristics do plants and animals have that increase their chances of reproduction?

Certain animal behaviors affect that probability. Behavior affects probability of reproduction. Animals have adapted a variety of courtship and mating behaviors to increase the probability of finding a mate. For example, the males of many bird species gyrate their feathers or perform special dances to attract a female.

Explanation:

"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."

because they are eaten by the frog and the frog getseaten by the snake and the snake by the eagle