Would a nerve cell and a blood cell from a human contain the same dna

Every cell of the body contains the same DNA. So, the nerve cells and the blood cells have the same set of genetic instructions.

Different cells are produced by differential use of that DNA. Different sets of genes must be turned on and off in the various cell types (differently expressed genes).

Most cells in a human body contain a complete set of the genome ( the genetic material of an organism), which is two sets of 23 chromosomes, with exception of egg and sperm cells, which carry only half a set of chromosomes (23 instead of 46).

"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."