Question

Predict the results of the experiment by Taylor, Woods, and Hughes if replication were(a) conservative and(b) dispersive.

Accepted Answer

Step 1: Understand the original experiment by Taylor, Woods, and Hughes, which used radioactive thymidine to label DNA and track replication patterns in chromosomes. The key observation was the distribution of labeled and unlabeled DNA after one and two rounds of replication. Step 2: For the conservative replication model, predict that after one round of replication, one daughter DNA molecule would be fully labeled (containing the original labeled strand) and the other would be completely unlabeled (newly synthesized strands). After the second round, you would expect a similar pattern with a mix of fully labeled and fully unlabeled DNA molecules. Step 3: For the dispersive replication model, predict that after one round of replication, all DNA molecules would contain a mixture of labeled and unlabeled segments within each strand, resulting in intermediate labeling throughout. After the second round, the label would be further diluted but still present in all DNA molecules, with no fully labeled or fully unlabeled strands. Step 4: Compare these predictions to the actual experimental results, which showed semi-conservative replication, where each daughter molecule contains one labeled (old) strand and one unlabeled (new) strand after the first replication. Step 5: Summarize that the conservative model predicts distinct fully labeled and unlabeled DNA molecules, while the dispersive model predicts uniformly mixed labeling in all DNA molecules, which contrasts with the semi-conservative pattern observed by Taylor, Woods, and Hughes.

Predict the results of the experiment by Taylor, Woods, and Hughes if replication were
(a) conservative and
(b) dispersive.

Verified video answer for a similar problem:

Key Concepts

DNA Replication Models

Taylor, Woods, and Hughes Experiment

Predicted Outcomes of Conservative and Dispersive Replication