Multiple Choice The photographs showed the bases of DNA were held together by hydrogen bonds. The photographs showed the location of each adenine, guanine, cytosine, and thymine. The photographs indicated that DNA has a double helix structure. The photographs revealed the structure of the deoxyribose sugar. The photographs showed equal numbers of purines and pyrimidines.

i dont know this but ask your teacher for !

"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."

ucd e e. rr. t t t t t t. to

hydrogen is a compound or a single element and a element is a pure substence that cannot be separated into simpler subtances

clorine is a compound its a chemical substance that forms when two or more different elements combine

so both hydrogen and clorine are compounds