PATHOLOGY MCQ
CELL DAMAGE
|
Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
|
|
|
cyclins and MPF
|
|
|
cyclins only
|
|
|
MPF only
|
|
|
Cdk’s and MPF
|
Detailed explanation-1: -For the cell to proceed through mitosis, MPF must be inactivated and other cyclins become active. This occurs through the destruction of cyclin M. During metaphase, MPF activates another protein complex called anaphase-promoting complex/cyclosome (APC/C).
Detailed explanation-2: -At the end of mitosis both SPF and MPF activities disappear because their cyclin subunits are degraded [5]. During G1 phase of the following cell cycle, when both SPF and MPF activities are low [6], origins of replication can be relicensed for another round of DNA synthesis [7, 8].
Detailed explanation-3: -In animal cells, MPF is cytoplasmic in interphase and is translocated into the nucleus after mitosis has begun, after which it associates with the mitotic apparatus until the cyclins are degraded in anaphase.