Question

Cyclin-dependent kinases (CDK) are proteins that work with cyclin-regulatory proteins. The cyclins are associated with different checkpoints of the cell cycle. Different phases of the cell cycle experience activation and/or deactivation of specific cyclin-Cdk complexes. CyclinB-CDK1 activity is specific to the G2/M checkpoint. Which statement is cycle B having a negative consequence on a cell?

Answer 1

If CyclinB-CDK1 activity is not properly regulated at the G2/M checkpoint, it can have a negative consequence on a cell.

The G2/M checkpoint is a critical control point in the cell cycle that ensures proper segregation of chromosomes during cell division. CyclinB-CDK1 activity is necessary for the cell to progress from the G2 phase to the M phase of the cell cycle. However, if CyclinB-CDK1 activity is not tightly regulated, it can lead to abnormal cell division and genomic instability, which can result in the development of genetic diseases or cancer.

For example, if CyclinB-CDK1 activity is too high, it can cause premature entry into mitosis, leading to chromosome missegregation and aneuploidy. On the other hand, if CyclinB-CDK1 activity is too low, it can delay entry into mitosis, leading to chromosome breakage and defective cell division.

Therefore, improper regulation of CyclinB-CDK1 activity can have negative consequences on a cell, ultimately leading to genomic instability and disease.