11. Cell Division

Checkpoints within the cell cycle:

The M phase checkpoint ensures that all chromosomes are attached to the mitotic spindle. If this does not happen, cells would most likely be arrested in ________.

Which of the following cell cycle checkpoints ensures that the genetic material is fully replicated before mitosis?

Progression through the cell cycle is regulated by oscillations in the concentration of which type of molecule?

a. p53, Rb, and other tumor suppressors

b. Receptor tyrosine kinases

c. Cyclins

d. Cyclin-dependent kinases

The decline of MPF activity at the end of mitosis is due to

a. The destruction of the protein kinase Cdk

b. Decreased synthesis of Cdk

c. The degradation of cyclin

d. The accumulation of cyclin

Which of the following occurs during apoptosis?

a. Lysis of the cell

b. Direct contact between signaling cells

c. Fragmentation of the DNA

d. Release of proteases outside the cell

Apoptosis involves all but which of the following?

a. Fragmentation of the DNA

b. Cell-signaling pathways

c. Lysis of the cell

d. Digestion of cellular contents by scavenger cells

In the cells of some organisms, mitosis occurs without cytokinesis. This will result in

a. Cells with more than one nucleus

b. Cells that are unusually small

c. Cells lacking nuclei

d. Cell cycles lacking an S phase

Cytochalasin B is a chemical that disrupts microfilament formation. This chemical would interfere with:

a. DNA replication

b. Formation of the mitotic spindle

c. Cleavage

d. Formation of the cell plate

Discuss the factors that control the division of eukaryotic cells grown in the laboratory. Cancer cells are easier to grow in the lab than other cells.

Why do you suppose this is?