After Watson and Crick proposed the double helix structure for DNA, three models for DNA replication were proposed: conservative, semiconservative, and dispersive. In the conservative model, the first replication produces one daughter molecule containing both parental strands and another containing all new strands. In the semiconservative model, each parental strand is a template for a new strand. Each daughter molecule has a parental strand and a new strand. In the dispersive model, each parental strand is broken into double-stranded segments that act as templates for new molecules. The segments then reassemble into complete double helices, each with parental and new segments interspersed.
Questions:
1. Suppose you were a scientist evaluating these three models when they were first proposed. What would have been your hypothesis regarding which model was correct? Explain
2. Which two models have similar results after replication cycle 1?
3 Why were culture samples taken after each replication cycle?
4. Which model(s), if any, is ruled out by the experimental results of replication cycle 1? Explain.
5. Which model is proved correct by the experimental results of replication cycle 2? Explain.