Question

Which of the following is the most likely effect of a mutation in the gene coding for a DNA repair enzyme?

- The cell containing the mutation will divide more frequently because the cell cycle checkpoints will not function properly.

- Mutations will accumulate more quickly because the cell will not be able to fix errors in replication.

- The mutated gene will not be transcribed because RNA polymerase cannot transcribe mutated DNA.

- The cell will immediately undergo apoptosis so that mutated DNA is not replicated in future rounds of cell division.

Answer 1

Ans) - The cell containing the mutation will divide more frequently because the cell cycle checkpoints will not function properly

Explaiantion: p53 is gene code for dna repair enzyme . In normal condition it activate p21 which. in turn deaactivate the CDK so result in cell cycle arrest and also activate BAX proteins to inhibit BCL 2 which induces apoptosis.

But in caase of mutaation DNA daamage could not inducep53

So p21 formation does not occur and further CDK do not inhibited so result in continuous cell cycle leads to cancer.