LABORATORY REVIEW
MITOSIS AND MEIOSIS
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
cyclin interacts with CdK to initiate the mitotic phase
|
|
|
cyclin acts as an inhibitor to CdK to wait for all DNA to be synthesized
|
|
|
cyclin is the precursor to CdK; when synthesized it allows for mitosis to proceed
|
|
|
cyclin binds to CdK to initiate DNA replication
|
Detailed explanation-1: -One subunit of MPF is cyclin, a regulatory polypeptide. The other subunit, cyclin-dependent kinase (cdk), contains the kinase enzyme active site. Both subunits must be bound to make an active kinase.
Detailed explanation-2: -M-phase cyclins form M-CDK complexes and drive the cell’s entry into mitosis; G1 cyclins form G1-CDK complexes and guide the cell’s progress through the G1 phase; and so on. All CDKs exist in similar amounts throughout the entire cell cycle.
Detailed explanation-3: -Formation of the cyclin/CDK complexes results in phosphorylation and activation of the CDKs. Activated cyclin/CDK complexes phosphorylate specific protein substrates that enable cell cycle progression.
Detailed explanation-4: -Cyclin/CDK complexes are known to regulate both mitotic and meiotic cell cycles. While some mechanisms are common to both types of cell divisions, meiosis has unique characteristics and requirements. During meiosis, DNA replication is followed by two successive rounds of cell division.