1.) X-Rays can break the sugar-phosphate backbone of
DNA. What type of bond breaks when this occurs?
a. Phosphodiester Bond
b. Nitrogenous bond
c. Hydroxyl bond
2.) The answer is not b. for the second question below
Suppose that Meselson and Stahl first grew cells in light nitrogen (Generation O) and switched to heavy nitrogen (N15) for two rounds of replication. If the semiconservative model of DNA replication were true, what would have Meselson and Stahl observed in the tubes after two rounds of DNA replication? Choose the letter corresponding to the correct drawing below d. ← Light ←Intermediate ←Heavy