11. Cell Division

The difference between benign and malignant tumors is:

Which of the following processes do normal proto-oncogenes typically exhibit?

When activated by signals in the cell, Protein X can stop cells from growing and dividing into new cells. What type of gene codes for Protein X?

Vinblastine is a standard chemotherapeutic drug used to treat cancer. Because it interferes with the assembly of microtubules, its effectiveness must be related to a. disruption of mitotic spindle formation. b. suppression of cyclin production. c. myosin denaturation and inhibition of cleavage furrow formation. d.inhibition of DNA synthesis.

One difference between cancer cells and normal cells is that cancer cells a. are unable to synthesize DNA. b. are arrested at the S phase of the cell cycle. c. continue to divide even when they are tightly packed together. d. cannot function properly because they are affected by density-dependent inhibition.

Evaluate each of the following defects. Which could lead to uncontrolled growth in cancer? Select True or False for each statement. T/F The overexpression of MPF activity. T/F A nonfunctional Rb protein. T/F The overexpression of G1 cyclin. T/F A nonfunctional E2F protein.