NEET BIOLOGY

Detailed explanation-1: -The G2 checkpoint ensures all of the chromosomes have been replicated and that the replicated DNA is not damaged before cell enters mitosis. The M checkpoint determines whether all the sister chromatids are correctly attached to the spindle microtubules before the cell enters the irreversible anaphase stage.

Detailed explanation-2: -G2/M checkpoints include the checks for damaged DNA, unreplicated DNA, and checks that ensure that the genome is replicated once and only once per cell cycle. If cells pass these checkpoints, they follow normal transition to the M phase.

Detailed explanation-3: -The G2-phase checkpoint, also known as G2/M-phase checkpoint, has the function of preventing cells with damaged DNA, lasting from the G1 and S phases or generated in G2, from undergoing mitosis. The mechanisms acting during the G2-phase checkpoint converge on the inhibition of the mitotic complex CDK1-cyclin B.

Detailed explanation-4: -If errors or damage are detected, the cell will pause at the G 2start subscript, 2, end subscript checkpoint to allow for repairs. If the checkpoint mechanisms detect problems with the DNA, the cell cycle is halted, and the cell attempts to either complete DNA replication or repair the damaged DNA.

Detailed explanation-5: -In the present study, we demonstrate that the failure of the early G2/M checkpoint to be activated by low concentrations of etoposide results in stable chromosomal aberrations, emphasizing a concomitant role of environmental and genetic risk factors for the development of chromosomal translocations.