Multiple Choice
Which phase of the cell cycle is primarily responsible for the separation of sister chromatids during cell division?
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16. Cell Division
Overview of the Cell Cycle
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Which of the following best describes the role of cyclins and cyclin-dependent kinases (CDKs) in the cell cycle?
A
They directly replicate DNA during the S phase.
B
They regulate the progression of the cell cycle by activating specific target proteins at key checkpoints.
C
They form the mitotic spindle required for chromosome separation.
D
They degrade damaged organelles through autophagy.
Verified step by step guidance1
Understand the role of cyclins and cyclin-dependent kinases (CDKs) in the cell cycle. Cyclins are regulatory proteins that bind to CDKs, activating them to phosphorylate specific target proteins.
Recognize that CDKs are enzymes that require cyclins to become active. The cyclin-CDK complexes are responsible for regulating the progression of the cell cycle by ensuring that key events occur at the correct time.
Identify the checkpoints in the cell cycle where cyclin-CDK complexes play a role. These include the G1/S checkpoint (to initiate DNA replication), the G2/M checkpoint (to prepare for mitosis), and the metaphase-anaphase transition (to ensure proper chromosome alignment).
Eliminate incorrect options by understanding that cyclins and CDKs do not directly replicate DNA, form the mitotic spindle, or degrade damaged organelles. Instead, they regulate the cell cycle by activating specific proteins at these checkpoints.
Conclude that the correct description of cyclins and CDKs is: 'They regulate the progression of the cell cycle by activating specific target proteins at key checkpoints.'
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Overview of the Cell Cycle practice set
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