Answer to Question #149657 in Biochemistry for jethro wyn elum

Question

How can mutations accumulate, given that the ells have repair systems that fix changes or breaks in DNA strands?

Answer 1

Cells have a variety of mechanisms to prevent mutations, or permanent changes in DNA sequence. These mechanisms include; chemical reversal, excision repair, and double-stranded break repair. However, mutations happen, and get passed on to daughter cells, only when these mechanisms fail. Cancer, in turn, develops only when multiple mutations in division-related genes accumulate in the same cell. This is a case of mutations accumulation.