Question

Why do mutations in the mismatch repair pathway proteins increase an individual's risk for cancer?

(A) If the mismatch repair pathway isn't functional, there will be an increase in Okazaki fragments that are unligated
(B) If the mismatch repair pathway isn't functional, then DNA replication cannot occur
(C) If the mismatch repair pathway isn't functional, then the mutation rate will increase
(D) All of the above

Answer 1

Mutations in mismatch repair proteins lead to increased mutational rates because of the failure to correct replication errors, potentially resulting in uncontrolled cell growth and cancer.

Step-by-step explanation:

Mutations in the mismatch repair pathway proteins increase an individual's risk for cancer because such mutations result in an impaired ability to correct errors that occur during DNA replication. The correct answer to the question is (C) If the mismatch repair pathway isn't functional, then the mutation rate will increase. The mismatch repair system is critical for fixing mistakes like base mismatches or insertion-deletion loops that can occur during DNA replication. When this system fails due to mutations, the DNA errors remain uncorrected, leading to an accumulation of mutations. Over time, these mutations can cause cells to grow uncontrollably, forming a cancerous tumor.