Question

Thinking question: What properties would you expect an E. coli cell to have if it had a temperature-sensitive mutation in the gene for DNA polymerase I?

A) Enhanced DNA repair; increased processivity during replication.
B) Altered RNA synthesis; improved fidelity in protein translation.
C) Impaired DNA replication; decreased Okazaki fragment synthesis.
D) Accelerated cell division; reduced sensitivity to DNA damage.

Answer 1

An E. coli cell with a temperature-sensitive mutation in DNA polymerase I would likely show impaired DNA replication and decreased Okazaki fragment synthesis at higher temperatures, aligning with option C.

Step-by-step explanation:

If an E. coli cell had a temperature-sensitive mutation in the gene for DNA polymerase I, we would expect to see impaired DNA replication and decreased Okazaki fragment synthesis at non-permissive temperatures. This is because DNA polymerase I is pivotal to the DNA repair process and the synthesis of Okazaki fragments during replication. At permissive temperatures, the enzyme might function normally, but at higher temperatures leading to the activation of the mutation, its function would degrade. Hence, the correct answer to the expected properties of an E. coli cell with such mutation would be 'Impaired DNA replication; decreased Okazaki fragment synthesis', corresponds to option C.