Molecular Genetic Mechanisms of Regulation of the Mitotic Cycle

A protein that checks for damaged DNA, thereby acting as a "guardian of the genome" for the cell.

• EF2

• cycline

• CDK

• P53

• P21

What factor is the growth factor of cells of the hematopoietic system?

• erythropoietin

• EGF

• cadherin

• interleukin

• lectin

Human skin cells divide about once a day. Which of the following conditions can prevent a skin cell from passing the G1 checkpoint?

• the presence of growth factors

• attachment of chromosomes to spindle fibers

• incomplete DNA replication

• damage to cell DNA

• the presence of mitogenic substances

Which of the following statements correctly describes the role of the p53 protein?

• is a receptor that binds to fibroblast growth factor

• blocking proteins involved in starting the cell cycle

• p53 is a proto-oncogene whose mutation causes cancer

• p53 activation leads to MPF inhibition

• activates DNA chromatin condensation

A eukaryotic cell that receives a go signal at the G1 checkpoint of the cell cycle will

• go directly to period G0

• move directly into M-period

• go directly to the G2 phase

• complete the cycle and split

• go to S-period

Synthesis of cyclin D is triggered after attaching a signal molecule to the receptor. In non-dividing cells, the concentration of cyclin D is low; it cannot attach to Cdk 4/6. Determine which protein prevents the formation of this complex?

• p21

• p16

• p53

• p27

• p14b

Determine which complex phosphorylates the Rb protein and promotes its detachment from E2F?

• cyclin D - Cdk4/6

• cyclin B - Cdk2

• cyclin E - Cdk2

• cyclin B - Cdk1

• cyclin A-Cdk2

After completion of the metaphase in the cell, the concentration of the B-Cdk1 complex begins to decrease. Determine where the degradation of this complex occurs?

• lysosome

• liposome

• nucleosome

• spliceosome

• proteosome

At the end of the post-mitotic cycle, damage occurred in the DNA molecule. To stop the mitotic cycle at the G1 and S interface, the cell needs to inhibit the Cdk2-CycE complex. Determine which protein is an inhibitor of this complex?

• p16

• p17

• p27

• p21

• p53

Signal transmission from the cell surface to the nucleus proceeds through a cascade of sequential protein phosphorylation. Specify which cytoplasmic proteins are transcription factors for cyclins?

• SMAD

• MEK

• MYC

• MAPK

• TK