At which phase are centrioles beginning to move apart in animal cells?

Prophase

Which of the following describe(s) cyclin-dependent kinase (Cdk)?

Cdk is present throughout the cell cycle and is an enzyme that attaches phosphate groups to other proteins.

Which number represents the point in the cell cycle during which the chromosomes are replicated?

II

Which of the following was a discovery that had to be made before human chromosomes could be correctly counted?

how to use a hypotonic solution to swell nuclei

MPF reaches its threshold concentration at the end of this stage.

III

Where do the microtubules of the spindle originate during mitosis in both plant and animal cells?

centrosome

Taxol is an anticancer drug extracted from the Pacific yew tree. In animal cells, Taxol disrupts microtubule formation by binding to microtubules and accelerating their assembly from the protein precursor, tubulin. Surprisingly, this stops mitosis. Specifically, Taxol must

the formation of the mitotic spindle.

A plant-derived protein known as colchicine can be used to poison cells by blocking the formation of the spindle. Which of the following would result if colchicine is added to a sample of cells in G₂?

The chromosomes would coil and shorten but have no spindle to which to attach

The centromere is a region in which

chromatids remain attached to one another until anaphase.

For a chemotherapeutic drug to be useful for treating cancer cells, which of the following is most desirable?

It interferes with rapidly dividing cells

Vinblastine is a standard chemotherapeutic drug used to treat cancer. Because it interferes with the assembly of microtubules, its effectiveness must be related to

disruption of mitotic spindle formation.

If there are 20 chromatids in a cell, how many centromeres are there?

10

After which checkpoint is the cell first committed to continue the cell cycle through M?

G₁

What is the correct chromosomal condition for one daughter nucleus at telophase of mitosis?

E

Besides the ability of some cancer cells to overproliferate, what else could logically result in a tumor?

lack of appropriate cell death

Which of the following most accurately describes a cyclin?

It activates a Cdk molecule when it is in sufficient concentration.

What is the correct chromosomal condition at the prometaphase of mitosis?

B

In the figure above, mitosis is represented by which numbered part(s) of the cycle?

IV

What is a cleavage furrow?

a groove in the plasma membrane between daughter nuclei

Which of the following does not occur during mitosis?

replication of the DNA

Which of the following is a protein maintained at constant levels throughout the cell cycle that requires cyclin to become catalytically active?

Cdk

Why do chromosomes coil during mitosis?

to allow the chromosomes to move without becoming entangled and breaking

A research team began a study of a cultured cell line. Their preliminary observations showed them that the cell line did not exhibit either density-dependent inhibition or anchorage dependence. What could they conclude right away?

The cells show characteristics of tumors.

Density-dependent inhibition is explained by which of the following?

As cells become more numerous, the cell surface proteins of one cell contact the adjoining cells and they stop dividing.

Which of the following is a protein maintained at constant levels throughout the cell cycle that requires cyclin to become catalytically active?

Cdk

G₁ is represented by which numbered part(s) of the cycle?

I or V

Which of the following is true concerning cancer cells?

Which of the following is a protein synthesized at specific times during the cell cycle that associates with a kinase to form a catalytically active complex?

cyclin

At which phase are centrioles beginning to move apart in animal cells?

Prophase

Which number represents DNA synthesis?

II

Movement of the chromosomes during anaphase would be most affected by a drug that

prevents shortening of microtubules

The cyclin component of MPF is destroyed toward the end of which phase?

M

Which of the following is released by platelets in the vicinity of an injury?

PDGF

If cells in the process of dividing are subjected to colchicine, a drug that interferes with the formation of the spindle apparatus, at which stage will mitosis be arrested?

metaphase

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

the degradation of cyclin