Cell Cycle

what are the roles of gap phases (G1, G2) 

There is a nondisjunction error in your DNA. At which check point will you find out?

• G1

• G2

• S

• M

Assuming that a particular cell type can only live for maximum 30 days. Given what you know about the Hayflick limit and the cell cycle, would you expect to find that cell still kicking around in 20 years?

• No. The telomeres would be exhausted and the cell would apoptose

• No. The Cell will die within 30 days.

• Yes. There are no exomes in the telomeres, so the cell would be fine.

• Yes. The cell would enter quiescence, prolonging their viability.

What occurs with cyclins that trigger various cell cycle events? 

• cyclin release signals the drive the cycle to S phase 

• Cdks have no part in the control of the cell cycle

• cyclical changes in concentrations lead to activation of cyclin-Cdk complexes

Would active S-Cdk occur before or after S phase? 

• before

• after

M-cyclin accumulates in G2, what does this bind to and what eventually inactivates it? 

• This binds to an APC/C; inactivated by inhibitory kinase 

• This binds to M-Cdk; inactivated by phosphate

Which of the following is not a function of the M-Cyclin-CDK complex?

• Chromosomal condesnastion

• Nucleolus degradation

• Dynamin pinching

• spindle formation

What is critical for the abrupt degradation of M and S cyclin partway through the M phase? 

• M-Cdk and S-Cdk 

• APC/C

• Cdk inhibitor proteins 

What would happen in the cell if the mitogen receptor was non-functional?

• S-CDK would be destroyed

• The cell would not enter the S phase

• The homologous chromosomes will not swap genetic material

• The Cell would create too many copies of its genome

The absence of p21 in a cell may indicate which of the following? (Assume that each option is independent of the others).

• There is DNA damage

• There is no DNA damage

• p53 is mutated

• p53 is phosphorylated