Along with water conservation animals also have unique characteristics for

They may be soggy and stinky, but they provide critical habitat for tons of plants and animals, help clean our water, control floods, and provide food for humans.

"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."

the unequal cytoplasmic division that  results  in  one egg  and three polar bodies ensures that a fertilized  egg has  ample nutrients  forits journey  to  the uterus.