검증된 단계별 안내
03:21
08:09
03:37The drug cytochalasin B blocks the function of actin. Which of the following aspects of the animal cell cycle would be most disrupted by cytochalasin B?
a. Spindle formation
b. Spindle attachment to kinetochores
c. Cell elongation during anaphase
d. Cleavage furrow formation and cytokinesis
The light micrograph shows dividing cells near the tip of an onion root. Identify a cell in each of the following stages: prophase, prometaphase, metaphase, anaphase, and telophase. Describe the major events occurring at each stage.
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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
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
Cell A has half as much DNA as cells B, C, and D in a mitotically active tissue. Cell A is most likely in
a. G1
b. G2
c. Prophase
d. Metaphase
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
