Answer the following questions concerning the accuracy of DNA polymerase during replication.
Identify two mechanisms that can correct the kind of abnormality resulting from the circumstances identified in part (c).

Verified step by step guidance

1. Understand the role of DNA polymerase in replication: DNA polymerase is responsible for synthesizing new DNA strands by adding nucleotides complementary to the template strand. It has a proofreading ability to ensure accuracy during replication.
2. Learn about the proofreading mechanism: DNA polymerase has 3' to 5' exonuclease activity, which allows it to remove incorrectly paired nucleotides immediately after they are added. This mechanism significantly reduces the error rate during replication.
3. Explore mismatch repair: If an error escapes the proofreading activity of DNA polymerase, mismatch repair enzymes can identify and correct mismatched base pairs. These enzymes recognize distortions in the DNA helix caused by mismatches, excise the incorrect segment, and replace it with the correct sequence.
4. Understand the role of post-replication repair: In cases where errors persist after replication, post-replication repair mechanisms, such as homologous recombination, can resolve abnormalities by using the undamaged sister chromatid as a template to repair the DNA.
5. Review the importance of these mechanisms: Both proofreading by DNA polymerase and mismatch repair are essential for maintaining genomic stability and preventing mutations that could lead to diseases such as cancer.

Key Concepts

DNA Polymerase Function

DNA polymerase is an enzyme responsible for synthesizing new DNA strands during replication. It adds nucleotides to a growing DNA chain by matching them with the template strand. While it has a high fidelity rate, errors can occur, necessitating correction mechanisms to maintain genetic integrity.

Proofreading Mechanism

Proofreading is a critical function of DNA polymerase that allows it to detect and correct mismatched nucleotides during DNA synthesis. This process involves the enzyme's 3' to 5' exonuclease activity, which removes incorrectly paired nucleotides, ensuring that the newly synthesized DNA is accurate.

Mismatch Repair System

The mismatch repair system is a post-replication repair mechanism that identifies and corrects errors that escape the proofreading activity of DNA polymerase. This system involves several proteins that recognize mismatches, excise the erroneous segment, and fill in the correct nucleotides, thereby preserving genomic stability.