Cell Cycle Regulation and DNA Damage Response Quiz

What is the initial response of a cell when its DNA is damaged?

• The cell calls in proteins like ATM and ATR.

• The cell ignores the damage.

• The cell repairs the DNA without any proteins.

• The cell immediately divides.

Which proteins are responsible for adding a phosphate to the p53 protein?

• G1/S-Cdk complexes

• Chk1 and Chk2 kinases

• ATM and ATR

• Mdm2

What happens to p53 when it is phosphorylated?

• It binds to G1/S-Cdk complexes.

• It becomes active and stable.

• It is marked for destruction by Mdm2.

• It becomes inactive and unstable.

What role does the p21 protein play in the cell cycle?

• It promotes cell division.

• It acts as an inhibitor, stopping the cell cycle.

• It repairs damaged DNA.

• It marks p53 for destruction.

How does p21 prevent cell division?

• By promoting the synthesis of new DNA.

• By activating G1/S-Cdk and S-Cdk complexes.

• By binding and inactivating G1/S-Cdk and S-Cdk complexes.

• By destroying the cell's DNA.