Question

Approximately how many base pairs are still improperly matched in the bacterial genome after the dna polymerase proofreads the dna strand?

A) 1 in 10,000
B) 1 in 100,000
C) 1 in 1,000,000
D) 1 in 100,000,000
E) 1 in a billion

Answer 1

On average, there is approximately 1 error in 10 million base pairs after DNA polymerase proofreads the DNA strand in bacterial genomes.

Step-by-step explanation:

After the DNA polymerase has proofread the DNA strand, approximately 1 in 10 million base pairs are still improperly matched in the bacterial genome. DNA polymerases can make errors during DNA replication, but due to their proofreading ability, many of these errors are corrected.

The enzyme senses a mismatched base pair, slows down, and performs repeated hydrolyses until the incorrect base is reached and cut out by the enzyme's 3' exonuclease action. Consequently, the fidelity of DNA replication is quite high, resulting in very few mismatches that are not caught and corrected during the replication process.