If a man who has duchenne muscular dystrophy has kids with a woman who does not have or carry the allele, how many of their sons could have the disorder? a. none b. all

The answer is none. Since DMD is a recessive x-linked trait, the sons will receive the Y from the father, and an X from the mother. Since the mother does not have the disease and is not a carrier, the sons cannot get the recessive x.

b brown mice / white sand dunes

"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."