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

Verified step by step guidance

1. Understand the context: Taylor, Woods, and Hughes conducted an experiment to study DNA replication using radioactive labeling in Vicia faba (broad bean) root tips.
2. Recall the three models of DNA replication: conservative, semi-conservative, and dispersive.
3. For conservative replication: In the first generation, one daughter molecule would consist entirely of the original DNA strands, and the other would consist entirely of new strands. Predict the distribution of radioactive label in this scenario.
4. For dispersive replication: Each daughter DNA molecule would be a mix of old and new DNA segments. Predict how the radioactive label would be distributed across the DNA strands in this scenario.
5. Consider how the experimental results would differ between the conservative and dispersive models, focusing on the pattern of radioactive labeling observed in the DNA after replication.

Key Concepts

DNA Replication Models

DNA replication can occur through different models: conservative, semi-conservative, and dispersive. In the conservative model, the original DNA molecule remains intact, and a completely new copy is made. In the dispersive model, the original DNA is broken into pieces, and both strands contain segments of old and new DNA. Understanding these models is crucial for predicting experimental outcomes.

Experimental Design of Taylor, Woods, and Hughes

Taylor, Woods, and Hughes conducted experiments using the bacterium *Escherichia coli* to investigate DNA replication. They utilized isotopic labeling to trace the incorporation of new nucleotides into DNA. The design of their experiment allows for the differentiation between the various replication models based on the distribution of labeled DNA in the daughter strands.

Results Interpretation

Interpreting the results of the experiment involves analyzing the patterns of labeled DNA after replication. In a conservative model, one would expect to see distinct bands of fully labeled and fully unlabeled DNA. In a dispersive model, the bands would show a gradient of labeling, indicating a mix of old and new DNA. Understanding how to interpret these results is essential for predicting the outcomes of the experiment.