(Solved): Cyclins and checkpoints The cell cycle is tightly controlled in a succession of events involving: 1 ...

Cyclins and checkpoints The cell cycle is tightly controlled in a succession of events involving: 1. The orchestrated production and degradation of cyclins 2. The orchestrated activation of enzymes and transcription factors 3. The orchestrated inhibition and degradation of enzymes or transcription factors Cell biologists demonstrated that a protein called Rad17 was an important checkpoint protein. In fact, the inactivation of Rad 17 produces cells of unusual appearance. Moreover, Rad17 inactivation seems to increase cancer occurrence. Below is shown a spread of chromosomes in a cell where Rad17 has been inactivated: Comparison between the chromosomes of a healthy cell (left panel) and a Rad17inactivated cell (right panel). F21-Inhibition Homework $?$ Unanswered $?$ Due Dec 19th, 11:59 PM Further studies showed that Rad 17 is involved at a very specific moment in the cell cycle. Rad17 expression is turned ON by a specific cyclin-CDK complex. Looking again at the chromosome spread of the Rad17-inactivated cell, which cyclin-CDK complex do you think normally increases Rad17 expression? Select an answer and submit. For keyboard navigation, use the up/down arrow keys to select an answer. a Cyclin E-CDK2 b Cyclin A - CDK2 c Cyclin B - CDK1 d Cyclin D - CDK4/6 F22-Inhibition Homework $?$ Unanswered $?$ Due Dec 19th, 11:59 PM Once Rad17 is expressed and achieves its function, it then must be rapidly inactivated. Cells in which Rad17 does not drop after acting cannot complete the cell cycle. Considering what you saw on the pictures, which cyclin-CDK complex is involved in the degradation of Rad17? Select an answer and submit. For keyboard navigation, use the up/down arrow keys to select an answer. a Cyclin E-CDK2 b Cyclin A - CDK2 c Cyclin B - CDK1