Which of the following statements best describes the primary reason for the increased rate of mutation observed in cancer cells?

Core Concept

The primary reason for the increased rate of mutation observed in cancer cells is the decreased DNA repair mechanisms. This allows errors in DNA replication to go unchecked, leading to an accumulation of mutations that contribute to cancer. Option A is incorrect because while DNA replication errors can contribute to mutations, it is not the primary reason for the increased rate of mutation in cancer cells. Option C is incorrect because gene expression is not directly related to mutation rates. Option D is incorrect because gene pool variation is a concept related to genetic diversity, not mutation rates.