Biology: The Dynamic Science

Peter J. Russell, Paul E. Hertz, Beverly McMillan

Chapter 10

Cell Division and Mitosis - all with Video Answers

Educators

TT

Chapter Questions

Problem 1

During the cell cycle, the DNA mass of a cell:
a. decreases during G $_{1 .}$
b. decreases during metaphase.
c. increases during the S phase.
d. increases during $\mathrm{G}_{2}$
e. decreases during interphase.

AM

Andrea Meyer

Numerade Educator

Problem 2

A tumor suppressor protein, $\mathrm{p} 21$, inhibits Cdk $1 .$ The earliest effect of $\mathrm{p} 21$ on the cell cycle would be to stop the cell cycle at:
a. early $G_{1}$
b. late $G_{1}$
c. the S phase.
d. $G_{2}$
e. the mitotic prophase.

TT

Tucker Tornberg

Numerade Educator

Problem 3

A major difference between hereditary information in eukaryotes and prokaryotes is:
a. in prokaryotes, the hereditary information is distributed among individual, linear DNA molecules in the nucleus.
b. in eukaryotes, the hereditary information is encoded in a single, circular DNA molecule.
c. in prokaryotes, the hereditary information is usually distributed among multiple circular DNA molecules in the cytoplasm.
d. in eukaryotes, the hereditary information is distributed among individual, linear DNA molecules in the cytoplasm.
e. in eukaryotes, the hereditary information is distributed among individual, linear DNA molecules in the nucleus.

AM

Andrea Meyer

Numerade Educator

Problem 4

The major microtubule organizing center of the animal cell is:
a. chromosomes, composed of chromatids.
b. the centrosome, composed of centrioles.
c. the chromatin, composed of chromatids.
d. chromosomes, composed of centromere.
e. centrioles, composed of centrosome.

Caroline Jones

Numerade Educator

Problem 5

The chromatids separate into chromosomes:
a. during prophase.
b. going from prophase to metaphase.
c. going from anaphase to telophase.
d. going from metaphase to anaphase.
e. going from telophase to interphase.

TT

Tucker Tornberg

Numerade Educator

Problem 6

Which of the following statements about mitosis is incorrect?
a. Microtubules from the spindle poles attach to the kinetochores on the chromosomes.
b. In anaphase, the spindle separates sister chromatids and pulls them apart.
c. In metaphase, spindle microtubules align the chromosomes at the spindle midpoint.
d. Cytokinesis describes the movement of chromosomes.
e. Both the animal cell furrow and the plant cell plate form at their former spindle midpoint.

Caroline Jones

Numerade Educator

Problem 7

Mitomycin C is an anticancer drug that stops cell division by inserting itself into the strands of DNA and binding them together. This action is thought to have its major effect at:
a. late $G_{1}$, early S phases.
b. late $G_{2}$
c. prophase.
d. metaphase.
e. anaphase.

Caroline Jones

Numerade Educator

Problem 8

Which of the following statements about cell cycle regulators is incorrect?
a. The concentrations of cyclins change throughout the cell cycle.
b. Cyclins are present in all stages of the cell cycle except S.
c. Cyclin-Cdk complexes phosphorylate target proteins.
d. Cdks combine with cyclin to move the cycle into mitosis.
e. During anaphase of mitosis, cyclin is degraded, allowing mitosis to end.

Caroline Jones

Numerade Educator

Problem 9

Which of the following is not a characteristic of cancer cells?
a. less cytoplasmic volume than normal cells
b. an absence of cyclin
c. loss of adhesion to other cells
d. loss of control of cell division
e. loss of normal control of $\mathrm{G}_{1} / \mathrm{S}$ phase transition

Caroline Jones

Numerade Educator

Problem 10

Which of the following does not accurately characterize bacterial DNA?
a. The bacterial chromosome is a closed, circular molecule of DNA.
b. Bacterial DNA is organized into nucleosomes.
c. The primary DNA molecule of most bacteria is circular.
d. DNA is organized more simply in bacteria than in eukaryotes.
e. Positively charged proteins can combine with bacterial DNA.

Bryan Valdivia

Numerade Educator

Problem 11

In bacteria:
a. several chromosomes undergo mitosis.
b. binary fission produces four daughter cells.
c. replication begins at the origin (ori), and the DNA strands separate.
d. the plasma membrane plays an important role in separating the duplicated chromosomes into the two daughter cells.
e. the daughter cells receive different genetic information from the parent cell.

Caroline Jones

Numerade Educator

Problem 12

You have a means of measuring the amount of DNA in a single cell. You first measure the amount of DNA during G $_{1}$. At what points during the remainder of the cell cycle would you expect the amount of DNA per cell to change?

TT

Tucker Tornberg

Numerade Educator

Problem 13

A cell has 38 chromosomes. After mitosis and cell division, one daughter cell has 39 chromosomes and the other has $37 .$ What might have caused these abnormal chromosome numbers? What effects do you suppose this might have on cell function? Why?

TT

Tucker Tornberg

Numerade Educator

Problem 14

Paclitaxel (Taxol), a substance isolated from Pacific yew (Taxus brevifolia), is effective in the treatment of breast and ovarian cancers. It works by stabilizing microtubules, thereby preventing them from disassembling. Why would this activity slow or stop the growth of cancer cells?

TT

Tucker Tornberg

Numerade Educator

Problem 15

Many chemicals in the food we eat have the potential to affect the growth of cancer cells. Chocolate, for example, contains a number of flavonoid compounds, which act as natural antioxidants. Design an experiment to determine whether any of the flavonoids in chocolate inhibit the cell cycle of breast cancer cells that are growing in culture.

Josee Pacheco

Numerade Educator

Problem 16

The genes and proteins involved in cell cycle regulation in prokaryotes and eukaryotes are very different. However, both types of organisms use similar molecular regulatory reactions to coordinate DNA synthesis with cell division. What does this observation mean from an
evolutionary perspective?

TT

Tucker Tornberg

Numerade Educator