Chapter 11, Problem 1PDQ

HOW DOWE KNOW?

In this chapter, we focused on how DNA is replicated and synthesized. We also discussed recombination at the DNA level. Along the way, we encountered many opportunities to consider how this information was acquired. On the basis of these discussions, what answers would you propose to the following fundamental questions?

1. (a) What is the experimental basis for concluding that DNA replicates semiconservatively in both bacteria and eukaryotes?
2. (b) How was it demonstrated that DNA synthesis occurs under the direction of DNA polymerase III and not polymerase I?
3. (c) How do we know that in vivo DNA synthesis occurs in the 5′ to 3′ direction?
4. (d) How do we know that DNA synthesis is discontinuous on one of the two template strands?
5. (e) What observations reveal that a “telomere problem” exists during eukaryotic DNA replication, and how did we learn of the solution to this problem?