Chapter 12
Number correct: 20
Number incorrect: 0
1. There are a number of differences between fission of a bacterium and human cell
division. Which of the following is not one of them?
a. A bacterium has only one chromosome.
b. Duplicated bacterial chromosomes attach to the plasma membrane.
c. Bacteria are smaller and simpler than human cells.
d. Bacteria have to duplicate their DNA before dividing.
Correct. This is not a difference; both bacteria and all other eukaryotic cells, human
included, first duplicate their DNA before beginning cell division.
e. Human chromosomes are larger and more complex.
2. You would be unlikely to see which of the following human cells dividing?
a. nerve cell
Correct. Nerve cells are quite complex and specialized. After reaching maturity they enter
the G0 phase.
b. skin cell
c. cancer cell
d. cell from an embryo
e. intestinal lining cell
3. Which of the following correctly matches a phase of the cell cycle with its description?
a. M-duplication of DNA
b. S-immediately precedes cell division
c. G2-cell division
d. G1-immediately follows cell division
Correct. After mitosis and cytokinesis, the newly formed daughter cells enter the G1
phase.
e. All of the above are correctly matched.
4. A benign tumor is one in which the cancerous cells
a. migrate from the initial site of transformation to other organs or tissues
b. can divide indefinitely if an adequate supply of nutrients is available.
c. remain confined to their original site.
Correct. Benign tumors can often be surgically removed because their boundaries are
well defined.
d. have an unusual number of chromosomes.
e. can impair the functions of one or more organs.
5. In telophase of mitosis, the mitotic spindle breaks down and the chromatin uncoils.
This is essentially the opposite of what happens in
a. prophase.
Correct. During prophase we observe the formation of the spindle, the condensation of
chromatin, and the disappearance of the nucleolus.
b. interphase.
c. metaphase.
d. S phase.
e. anaphase.
6. Sister chromatids
a. are created when DNA is replicated.
b. are attached at the centromere prior to division.
c. are separated during mitosis.
d. have matching copies of the chromosome's DNA.
e. all of the above.
Correct. When cytokinesis follows mitosis, the sister chromatids become independent
chromosomes in the two daughter cells.
7. Which of the following is not a function of mitotic cell division in animals?
a. asexual reproduction
b. growth
c. repair of damaged organs
d. production of gametes
Correct. The cell division process which results in gametes is meiosis, not mitosis.
e. cell replacement
8. Observations with cancer cells in culture support the hypothesis that cancer cells
a. do not exhibit density-dependent inhibition.
Correct. Normal cells respond to density-dependent inhibition by growing in culture to
form a single layer of cells.
b. produce molecules which inhibit the growth factors required for cell division.
c. exhibit anchorage dependence.
d. spend the majority of their time in the Go phase.
e. all of the above
9. 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.
Correct. The cleavage furrow forms when the microfilament myosin interacts with the
actin (also a microfilament)ring, causing it to be drawn inward.
d. formation of the cell plate.
e. binary fission
10. Which of the following phases of mitosis is essentially the opposite of prometaphase
in terms of nuclear changes?
a. telophase
Correct. During telophase, fragments of the nuclear membrane begin to reassemble along
with portions of the endomembrane system.
b. metaphase
c. S phase
d. interphase
e. anaphase
11. If an intestinal cell in a grasshopper contains 24 chromosomes, a grasshopper sperm
cell would contain ____ chromosomes.
a. 3
b. 6
c. 12
Correct. The production of gametes by meiosis, produces cells with half the chromosome
number of a somatic cell. After fertilization, the chromosome number is restored.
d. 24
e. 48
12. Most cells will divide if they receive the proper signal at a checkpoint in the ____
phase of the cell cycle.
a. M
b. G1
Correct. In mammalian cells this checkpoint is termed the restriction point.
c. S
d. G2
e. cytokinesis
13. Tissue culture experiments with PDGF demonstrate that without this substance
a. bacterial cells lose their resistance to antibiotics.
b. cells divide in an uncontrolled fashion, confirming its role as a cell division inhibitor.
c. fibroblasts fail to divide.
Correct. PDGF is a specific growth factor for fibroblasts.
d. animal cells are unable to attach to the substratum.
e. the various kinases, such as MPF, are unable to bind to cyclin.
14. A human bone marrow cell, in prophase of mitosis, contains 46 chromosomes. How
many chromatids does it contain altogether?
a. 46
b. 92
Correct. Mitosis follows S phase, during which the cells DNA is duplicated.
c. 23
d. 23 or 46, depending on when during prophase you look
e. 46 or 92, depending on when during prophase you look
15. A biochemist measured the amount of DNA in cells growing in the laboratory and
found that the quantity of DNA in a cell doubled
a. between prophase and anaphase.
b. between the G1 and G2 phases.
Correct. Between these two phases of the cell cycle, the DNA is replicated during the S
phase.
c. during the M phase of the cell cycle.
d. between the G2 phase and prophase.
e. between anaphase and telophase.
16. When a cell in S phase is fused with a cell in G1
a. DNA synthesis begins immediately in the original G1 nucleus.
Correct. This observation indicates that cytoplasmic signals can participate in the
regulation of the cell cycle.
b. the replication of DNA occurring in the original S nucleus is terminated.
c. the two nuclei fuse, and further division is arrested.
d. the chromosomes of the original G1 nucleus condense in preparation of mitosis.
e. the cell will divide immediately
17. In some organisms such as certain fungi and algae, cells undergo mitosis repeatedly
without subsequently undergoing cytokinesis. What would result from this?
a. a decrease in chromosome number
b. inability to duplicate DNA
c. division of the organism into many cells, most lacking nuclei
d. large cells containing many nuclei
Correct. The term for this type of cell is multinucleated.
e. a rapid rate of sexual reproduction
18. A cell biologist carefully measured the quantity of DNA in grasshopper cells growing
in cell culture. Cells examined during the G2 phase of the cell cycle contained 200 units
of DNA. What would be the amount of DNA in one of the grasshopper daughter cells
seen in telophase of mitosis?
a. 50 units
b. 100 units
Correct. Recall that G2 follows S, and that during S phase, DNA is replicated.
c. between 50 and 100 units
d. 200 units
e. 400 units
19. It is difficult to observe individual chromosomes with a light microscope during
interphase because
a. the DNA has not been replicated yet.
b. they have uncoiled to form long, thin strands.
Correct. Except during M phase, the DNA is extended, allowing its genes to be
transcripted for protein synthesis.
c. they leave the nucleus and are dispersed to other parts of the cell.
d. sister chromatids do not pair up until division starts.
e. the spindle must move them to the metaphase plate before they become visible.
20. The kinetochores
a. are located at the center of the centrosome; their function is to organize tubulin into
elongated bundles called spindle fibers.
b. are the primary centromere structures which maintain the attachment of the sister
chromatids prior to mitosis.
c. move along spindle microtubules during anaphase, dragging their chromosome
toward one pole of the cell.
Correct. As the spindle depolymerizes, the kinetochores appear to move along the spindle
fiber, dragging the attached chromosomes with them.
d. of each spindle interdigitate at the cell's equator, and then move apart, causing the cell
to elongate.
e. attach to the ring of actin along the cytoplasmic surface of the plasma membrane,
causing the actin to contract to form the cleavage furrow.
Chapter 13
Number correct: 19
Number incorrect: 1
1. A DNA molecule is a polymer made of subunits called
a. bases.
b. amino acids.
c. nucleotides.
Correct. A 5-carbon sugar, a base, and a phosphate group form a nucleotide.
d. nucleic acids.
e. pyrimidines.
2. A human somatic cell contains _____ chromosomes.
a. 23
b. 47
c. 2n
d. 46
Correct. Human somatic cells contain 22 pairs of chromosomes and 2 sex chromosomes.
e. n
3. Which of the following is a normal human female?
a. X Y
b. X X Y
c. X X X
d. X
e. X X
Correct. Human females are X X.
4. A karyotype would be least likely to show which of the following?
a. an extra chromosome
b. part of a chromosome duplicated
d. a missing chromosome
d. part of a chromosome turned around
Correct. An inversion, which affects neither the number of chromosomes nor the length
of a chromosome, would be difficult to detect.
e. translocation
5. The diploid stage of a plant that exhibits an alternation of generation is the
a. antheridium.
b. gametophyte.
c. spore.
d. archegonium.
e. sporophyte.
Correct. The sporophyte produces haploid spores by meiosis.
6. DNA replication occurs
a. whenever a cell makes protein.
b. to repair gene damage caused by mutation.
c. before a cell divides.
Correct. This ensures that genetic material can be appropriately distributed to the
daughter cells.
d. whenever a cell needs RNA.
e. in the cytoplasm of a eukaryotic cell.
7. Mitosis and cytokinesis result in the formation of ______; meiosis and cytokinesis
result in the formation of ________.
a. 4 diploid cells; 4 haploid cells
b. 2 diploid cells; 2 haploid cells
c. 2 diploid cells; 4 haploid cells
Correct. In mitosis a cell that has doubled its genetic material divides into 2 diploid
daughter cells. In meiosis a cell that has doubled its genetic material undergoes 2 rounds
of division, resulting in the production of 4 haploid cells.
d. 2 diploid cells; 2 diploid cells.
e. 4 haploid cells; 2 diploid cells
8. Which of the following occurs during meiosis but not during mitosis?
a. Chromosomes align at the metaphase plate.
b. Chromosomes condense.
c. Chromosomes migrate to opposite poles.
d. Spindle apparatus forms.
e. synapsis
Correct. The pairing of homologous chromosomes during prophase I is called synapsis.
9. At the end of telophase I and cytokinesis there are
a. 4 haploid cells.
b. 2 diploid cells.
c. 4 diploid cells.
d. 1 haploid ovum and 3 polar bodies.
e. 2 haploid cells.
Correct. Each of these haploid cells consists of two chromatids.
See page 231 - 235 in Campbell Biology 5e
10. Synapsis occurs during
a. anaphase I.
b. prophase I.
Correct. Synapsis is the pairing of homologues during prophase I.
c. cytokinesis.
d. prophase II.
e. metaphase I.
11. During anaphase II
a. homologues separate and migrate towards opposite poles.
b. sister chromatids separate and migrate towards opposite poles.
Correct. This occurs during anaphase II.
c. nuclei reform.
d. chromosomes line up in a single file.
e. the cells are diploid.
12. During anaphase I
a. homologues separate and migrate towards opposite poles.
Correct. This occurs during anaphase I.
b. sister chromatids separate and migrate towards opposite poles.
c. nuclei reform.
d. chromosomes line up in a single file.
e. the cells are diploid.
13. Cytokinesis is the
a. exchange of homologous regions of nonsister chromatids.
b. formation of tetrads.
c. independent assortment of chromosomes.
d. transfer of genetic material via sex pili.
e. division of one cell into two.
Correct. Cytokinesis accompanies both telophase I and telophase II.
14. Centrioles separate during
a. cytokinesis.
b. prophase I and prophase II
Correct. As the centrioles, separate the spindle apparatus forms between them.
c. metaphase I and metaphase II.
d. anaphase I and anaphase II.
e. telophase I and telophase II.
15. Crossing over occurs during
a. cytokinesis.
b. metaphase I.
c. prophase II.
d. metaphase II.
e. prophase I.
Correct. Crossing over resulting in genetic recombination occurs during this phase.
16. Regions where nonsister chromatids cross are called
a. inversions.
b. homologues.
c. kinetochores.
d. chiasmata.
Correct. Chiasmata are regions where crossing over can occur.
e. tetrads.
17. In humans, the haploid number of chromosomes is 23. Independent assortment has
the possibility of producing _____ different gametes.
a. 232
b. 1 million
c. 223
Correct. 2 possibilities for each gamete, one from dad and one from mom, and 23
different chromosomes per gamete.
d. 24
e. 100,000
18. Crossing over is
a. the movement of genetic material from one chromosome to a nonhomologous
chromosome.
b. independent assortment of chromosomes.
c. the formation of chiasmata.
d. the exchange of homologous portions of nonsister chromatids.
Correct. The result is new genetic combination.
e. making an RNA copy of a DNA strand.
19. Variation occurs when chromosomes are shuffled in _____ and fertilization.
a. mitosis
b. genetic drift
c. natural selection
d. mutation
e. meiosis
Correct. Variation is produced as a result of independent assortment and crossing over.
20. Heritable variation is required for
a. meiosis.
b. mitosis.
c. evolution.
Correct. Variation is the raw material of evolution
d. asexual reproduction.
e. the production of a clone.