The Replication Of DNA

1. Define: replication.

2. DNA replication is semi-conservative. Explain.

3. What enzyme is required for the replication of DNA?

4. Meselson and Stahl investigated the replication of DNA. What were they trying to confirm?

5. At the time that the above investigators began their experiments, biologists were considering three possible mechanisms by which two complementary strands of the parental duplex DNA could yield daughter DNA duplexes identical to those of the parent. What were those mechanisms and what would they produce?

6. What organism did Meselson and Stahl use for their experiment? In order to label the DNA of the organisms, they were grown in a medium in which the sole nitrogen source was ammonium chloride. This was labeled with what isotope? What did this replace?

7. How were Meselson and Stahl able to separate DNA based on density? Explain how this works.

8. Describe the crucial experiment Meselson and Stahl carried out on the mechanism of DNA replication.

9. What were the results of the experiment? What was the conclusion?

10. In what direction does DNA polymerase synthesize DNA? Compare replication on the leading strand with replication on the lagging strand. What are Okazaki fragments?