Muscles in a kangaroo’s legs work because of the cells that make up the muscle. Which component of cell theory does this best illustrate? A. All living things are made of cells.
B. Cells are the basic unit of structure and function of all living things.
C. All cells come from other cells.
D. Cells are generated from nonliving materials.

id say b. cells are the basic unit stricture and function of all living things.

Explanation:

the kangaroo uses his muscles and his muscles are made of cells

"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."

answer; both surfaces of the membrane are nonpermeable