2. In 2012 some Harvard graduates were asked a simple question: Where does a plant get
its mass? Many of the students answered incorrectly that plants gained mass from
"eating" the soil.
a. Using specific information from your equational model, explain where plants
actually get their mass.
b. Propose a simple experiment that could support your explanation.

The mass of a tree is primarily carbon.

Explanation:

The carbon comes from carbon dioxide used during photosynthesis.

"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."