Question

Which of the following defects is most likely to be found in yeast cells with a dramatically increased rate of genomic mutation per cell cycle ?

Activation of a G1/S DNA damage checkpoint in the absence of DNA damage.

Activation of a G1 restriction point checkpoint despite adequate cell size and nutrient supply.

A silent mutation within a DNA replication polymerase.

A mutation that inactivates a gene encoding an essential component of a DNA damage checkpoint.

Activation of a G2/M DNA damage checkpoint in the absence of DNA damage.

Answer 1

The correct option is the fourth one.

A mutation occuring in a gene coding for an essential component of DNA damage checkpoint will lead to the increased rate of genomic mutation per cell cycle.It is because these checkpoint are the only gates which restricts the cell to enter to the next stage of cell division whenever DNA damage is found. So, any defect occuring in these checkpoint will lead to the accumulation of mutations per cell cycle.

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