Deck 11: The Cell Cycle and Cell Division

Question 1

In meiosis,

A) a single nucleus gives rise to two daughter nuclei.
B) the daughter nuclei are genetically identical to the parent nucleus.
C) the centromeres separate at the onset of anaphase I.
D) homologous chromosomes synapse in prophase I.
E) no spindle forms.

Answer 1

D

Question 2

DNA replication occurs

A) during both mitosis and meiosis.
B) only during mitosis.
C) only during meiosis.
D) during the S phase.
E) during G2.

Answer 2

D

Question 3

Which statement about eukaryotic chromosomes is not true?

A) They sometimes consist of two chromatids.
B) They sometimes consist only of a single chromatid.
C) They normally possess a single centromere.
D) They consist only of proteins.
E) During metaphase they are visible under the light microscope.

Answer 3

D

Question 4

During the bacterial cell division, the single cells is separated into two cells by

A) centrosomes.
B) spindle fibers.
C) nucleosomes.
D) pinching of the plasma membrane.
E) aneuploidy.

Question 5

A set of cells in the intestinal epithelium divide continually to replace dead cells lost from the surface of the intestinal lining. If you examined this continually dividing population of intestinal epithelial cells under the microscope, most of the cells would

A) be in meiosis.
B) be in mitosis.
C) be in interphase.
D) have condensed chromatin.
E) Both b and d

Question 6

Apoptosis

A) occurs in all cells.
B) involves the formation of the plasma membrane.
C) does not occur in an embryo.
D) is a series of programmed events resulting in cell death.
E) is the same as necrosis.

Question 7

Which of the following is not true about cervical cancer, which is a relatively common cancer?

A) It can be detected early by a PAP test.
B) It is usually caused by human papillomavirus (HPV).
C) It causes the cervical cells to make peptide E7, which disrupts the cell cycle.
D) It spreads by blocking the retinoblastoma protein RB.
E) It usually remains localized.

Question 8

Nucleosomes

A) are made of chromosomes.
B) consist entirely of DNA.
C) consist of DNA wound around a histone core.
D) are present only during mitosis.
E) are present only during prophase.

Question 9

Cells that do not divide are usually arrested in

A) S.
B) G1.
C) G2.
D) M.
E) prophase.

Question 10

Which of the following statements about mitosis is true?

A) The chromosome number in the resulting cells is halved.
B) DNA replication is completed in prophase.
C) Crossing over occurs during prophase.
D) Two genetically identical daughter cells are formed.
E) It consists of two nuclear divisions.

Question 11

For a prokaryote cell to divide, which of the following must occur?

A) A reproductive signal, replication, segregation of DNA, and cytokinesis
B) DNA replication, crossing over, and segregation of DNA
C) DNA replication and segregation of DNA
D) Cell growth and cytokinesis
E) DNA replication, segregation of DNA, and cytokinesis

Question 12

Which statement about cytokinesis is true?

A) In animals, a cell plate forms.
B) In plants, it is initiated by furrowing of the membrane.
C) It follows mitosis.
D) In plant cells, actin and myosin play an important part.
E) It is the division of the nucleus.

Question 13

Bacteria typically have _______, whereas eukaryotes have _______.

A) one chromosome that is circular; many chromosomes that are linear
B) several chromosomes that are circular; many chromosomes that are linear
C) one chromosome that is linear; many chromosomes that are circular
D) two chromosomes that are circular; eight chromosomes that are linear
E) None of the above

Question 14

Mature nerve cells, which are incapable of cell division, are most likely in

A) G1.
B) the S phase.
C) G2.
D) mitosis.
E) meiosis.

Question 15

Which statement about the cell cycle is not true?

A) It consists of interphase, mitosis, and cytokinesis.
B) The cell's DNA replicates during G1.
C) A cell can remain in G1 for weeks or much longer.
D) DNA is not replicated during G2.
E) Cells enter the cell cycle as a result of internal or external signals.

Question 16

A bacterial cell gives rise to two genetically identical daughter cells by a process known as

A) nondisjunction.
B) mitosis.
C) meiosis.
D) fission.
E) fertilization.

Question 17

An animal has a diploid chromosome number of 12. An egg cell of that animal has 5 chromosomes. The most probable explanation is

A) normal mitosis.
B) normal meiosis.
C) nondisjunction in meiosis I.
D) nondisjunction in meiosis I or II.
E) nondisjunction in mitosis.

Question 18

In meiosis,

A) meiosis II reduces the chromosome number from diploid to haploid.
B) DNA replicates between meiosis I and meiosis II.
C) the chromatids that make up a chromosome in meiosis II are identical.
D) each chromosome in prophase I consists of four chromatids.
E) homologous chromosomes separate from one another in anaphase I.

Question 19

During prokaryotic cell division, two chromosomes separate from each other and distribute into the daughter cells by

A) attachment to microtubules.
B) a mitotic spindle.
C) repellent forces.
D) attachment to separating membrane regions.
E) All of the above

Question 20

Which statement about mitosis is not true?

A) A single nucleus gives rise to two identical daughter nuclei.
B) The daughter nuclei are genetically identical to the parent nucleus.
C) The centromeres separate at the onset of anaphase.
D) Homologous chromosomes synapse in prophase.
E) The centrosomes organize the microtubules of the spindle fibers.

Question 21

Which of the following phases of the cell cycle is not part of interphase?

A) M
B) S
C) G1
D) G2
E) G0

Question 22

The mitotic spindle is composed of

A) chromosomes.
B) chromatids.
C) microtubules.
D) chromatin.
E) centrosomes.

Question 23

Regulation of the cell cycle is dependent on cyclins and cyclin-dependent kinases. The key(s) that allows a cell to progress beyond the restriction point is (are)

A) Cdk1 and cyclin B.
B) cyclin D and p21.
C) cyclin A and Cdk2.
D) phosphorylation of RB by Cdk4 and Cdk2.
E) external signals from growth factors.

Question 24

Evidence from yeast suggests that the maturation-promoting factor of sea urchins is

A) a cyclin.
B) MFP.
C) an S nuclease.
D) a Cdk.
E) a Cdk/cyclin phosphatase.

Question 25

The initiation of the S phase and the M phase of the cell cycle depends on a pair of molecules called _______ and _______.

A) actin; myosin
B) Cdk's; cyclin
C) ligand; receptor
D) MSH; MSH-receptor
E) ATP; ATPase

Question 26

When cyclin binds Cdk,

A) the cell transitions from G2 to S.
B) kinase activation occurs.
C) chromosomes condense.
D) the cell quickly enters M phase.
E) the cell begins apoptosis.

Question 27

A typical cell cycle consists of

A) mitosis and meiosis.
B) G1, the S phase, and G2.
C) prophase, metaphase, anaphase, and telophase.
D) interphase, mitosis, and cytokinesis.
E) meiosis and fertilization.

Question 28

During mitosis and meiosis the chromatin compacts. Which of the following processes takes place more easily because of this compaction?

A) The orderly distribution of genetic material to two new nuclei
B) The replication of the DNA
C) Exposing the genetic information on the DNA
D) The unwinding of DNA from around the histones
E) The disappearance of the nuclear membrane

Question 29

The products of mitosis are

A) one nucleus containing twice as much DNA as the parent nucleus.
B) two genetically identical cells.
C) four nuclei containing half as much DNA as the parent nucleus.
D) four genetically identical nuclei.
E) two genetically identical nuclei.

Question 30

Chromosomes contain large amounts of interacting proteins known as

A) pentanes.
B) hexosamines.
C) histones.
D) protein hormones.
E) histamines.

Question 31

The basic structure of chromatin has sometimes been referred to as beads on a string of DNA. These beads are called

A) chromosomes.
B) chromatids.
C) supercoils.
D) interphases.
E) nucleosomes.

Question 32

Interleukins and erythropoietin are

A) growth factors.
B) Cdk's.
C) cyclins.
D) antitumor agents.
E) intracellular signaling molecules.

Question 33

How does a nucleus in G2 differ from a nucleus in G1?

A) The G2 nucleus has double the amount of DNA as the G1 nucleus.
B) DNA synthesis occurs only in the G1 phase.
C) Inactive cells are arrested only in the G2 phase.
D) During G2, the cell prepares for S phase.
E) All of the above

Question 34

Nucleosomes contain _______ and _______.

A) centromeres; DNA
B) microtubules; condensins
C) kinetochores; centromeres
D) histones; DNA
E) polar microtubules; kinetochore microtubules

Question 35

DNA damage by UV radiation causes the synthesis of

A) p53.
B) DNA.
C) Cdk.
D) cyclin.
E) p21.

Question 36

Chromatin consists of

A) DNA and histones.
B) DNA, histones, and many other nonhistone proteins.
C) mostly RNA and DNA.
D) RNA, DNA, and nonhistone proteins.
E) DNA only.

Question 37

The uncondensed length of human DNA found in chromosomes is _______, whereas a typical cell is 10 µm in length.

A) 5 µm
B) 2 µm
C) 2 meters
D) 20 meters
E) 2.54 inches

Question 38

Cyclin-dependent kinases (Cdk's) catalyze the phosphorylation of targeted proteins, a process that

A) decreases the mass of the protein.
B) makes the targeted proteins hydrophobic.
C) changes the shape and function of the targeted proteins.
D) gives the proteins a three-dimensional shape.
E) blocks the cell cycle from proceeding.

Question 39

The molecules that make up a chromosome are _______ and _______.

A) DNA; RNA
B) DNA; proteins
C) proteins; lipids
D) nucleotides; nucleosides
E) proteins; phospholipids

Question 40

The DNA of a eukaryotic cell is

A) double-stranded.
B) single-stranded.
C) circular.
D) complex inverted.
E) conservative.

Question 41

Microtubules that form the mitotic spindle tend to originate from or terminate in

A) centromeres and telomeres.
B) euchromatin.
C) centrioles and telomeres.
D) the nuclear envelope.
E) centrioles and kinetochores.

Question 42

The microtubules of the mitotic spindle attach to a specialized structure in the centromere region of each chromosome called the

A) kinetochore.
B) nucleosome.
C) equatorial plate.
D) aster.
E) centrosome.

Question 43

Which of the following is not involved in the separation of paired chromatids and their movement to opposite poles?

A) Sister chromatids attach to microtubules in opposite halves of the spindle.
B) Separase hydrolyzes cohesion, allowing chromatid separation.
C) Tubulin fibers move the chromatids away from the equatorial plate.
D) Polar microtubules push the chromatids to the poles.
E) ATP is hydrolyzed by cytoplasmic dynein.

Question 44

Which of the following statements about plant cytokinesis is true?

A) It begins when telophase ends.
B) A division furrow completely separates the cytoplasm.
C) It is under the control of Ca²⁺.
D) Vesicles fuse to form a cell plate.
E) The spindle fibers break down to form a cell plate.

Question 45

Centrosomes

A) are constricted regions of phase chromosomes.
B) determine the plane of cell division.
C) are the central region of the cell.
D) are the region where the membrane constricts during cytokinesis.
E) are part of cilia.

Question 46

Chromosomes "decondense" into diffuse chromatin

A) at the end of telophase.
B) at the beginning of prophase.
C) at the end of interphase.
D) at the end of metaphase.
E) only in dying cells.

Question 47

At the milestone that defines telophase, the chromosomes

A) separate.
B) come together.
C) are at opposite poles.
D) line up.
E) cross over.

Question 48

A mechanism for increasing the genetic diversity of offspring is

A) mitosis.
B) cloning.
C) sexual reproduction.
D) cytokinesis.
E) fission.

Question 49

After the centromeres separate during mitosis, the chromatids, now called _______, move toward opposite poles of the spindle.

A) centrosomes
B) kinetochores
C) half-spindles
D) asters
E) daughter chromosomes

Question 50

At the milestone that defines anaphase, the chromosomes

A) separate.
B) come together.
C) are at opposite poles.
D) line up.
E) cross over.

Question 51

In plant cells, cytokinesis is accomplished by the formation of a(n)

A) aster.
B) membrane furrow.
C) equatorial plate.
D) cell plate.
E) spindle.

Question 52

The energy to move chromosomes during mitosis is provided by

A) centrioles.
B) DNA polymerization.
C) migration of the centrosomes.
D) formation of the cell plate.
E) ATP.

Question 53

The distribution of mitochondria between the daughter cells during cytokinesis

A) is random.
B) is directed by the mitotic spindle.
C) is directed by the centrioles.
D) results in the mitochondria remaining in the parent cell.
E) occurs only during meiosis.

Question 54

The structures that line up the chromatids on the equatorial plate during metaphase are called

A) asters.
B) polar and kinetochore microtubules.
C) centrosomes.
D) centrioles.
E) histones.

Question 55

At the milestone that defines metaphase, the chromosomes

A) separate.
B) come together.
C) are at opposite poles.
D) line up at the equatorial plate.
E) cross over.

Question 56

During mitotic anaphase, chromosomes migrate

A) from the poles of the cell toward the equatorial plate.
B) from the equatorial plate toward the poles.
C) toward the nuclear envelope.
D) along with their sister chromatids toward one pole.
E) along with the other member of the homologous pair toward the equatorial plate.

Question 57

The event in the cell division process that clearly involves microfilaments is

A) chromosome separation during anaphase.
B) movement of chromosomes to the metaphase plate.
C) chromosome condensation during prophase.
D) disappearance of the nuclear envelope during prophase.
E) cytokinesis in animal cells.

Question 58

Which of the following does not occur during mitotic prometaphase?

A) Disappearance of the nuclear envelope
B) Initial movement of chromosomes toward the equatorial plate
C) Adhesion of chromatids at the centromere
D) Synapsis of homologous chromosomes
E) Disappearance of the nuclei

Question 59

When dividing cells are examined under a light microscope, chromosomes first become visible during

A) interphase.
B) the S phase.
C) prophase.
D) G1.
E) G2.

Question 60

Chromatin condenses to form discrete, visible chromosomes

A) early in G1.
B) during S.
C) during telophase.
D) during prophase.
E) at the end of cytokinesis.

Question 61

In a haploid organism, most mitosis occurs

A) after fertilization and before meiosis.
B) after meiosis and before fertilization.
C) between meiosis I and II.
D) during G1.
E) in diploid cells.

Question 62

A haploid cell is a cell

A) in which the genes are arranged haphazardly.
B) containing only one copy of each chromosome.
C) that has resulted from the process of mitosis.
D) with twice the number of chromosomes of a diploid cell.
E) None of the above

Question 63

Which of the following statements about homologous chromosome pairs is false?

A) They come from only one of the individual's parents.
B) They usually contain slightly different versions of the same genetic information.
C) They separate from each other during meiosis I.
D) They synapse during meiosis I.
E) Each contains two sister chromatids at the beginning of meiosis I.

Question 64

Human males have _______ sex chromosomes.

A) XX
B) XY
C) XO
D) three types of
E) 23

Question 65

The second meiotic division of meiosis is important because

A) it returns the chromosome number to diploid before fertilization.
B) it allows for crossing over and random distribution of chromosomes.
C) it reduces cell size by dividing the cytoplasm in half.
D) without this division, chromosome copies would double at each fertilization.
E) fertilization requires this step.

Question 66

At the end of the first meiotic division, each chromosome consists of

A) chiasmata.
B) a homologous chromosome pair.
C) four copies of each DNA molecule.
D) two chromatids.
E) a pair of polar microtubules.

Question 67

Sexual reproduction increases genetic variability through

A) the exchange of genetic information between male and female gametes during meiosis I.
B) the random separation of homologous chromosomes.
C) the union of male and female gametes.
D) crossing over, independent assortment, and random fertilization.
E) random assortment of male and female chromosomes.

Question 68

Asexual reproduction produces genetically identical individuals because

A) chromosomes do not have to replicate during asexual reproduction.
B) it involves chromosome replication without cytokinesis.
C) no meiosis or fertilization take place.
D) cell division occurs only in meiosis.
E) the mitotic spindle prevents nondisjunction.

Question 69

During asexual reproduction, the genetic material of the parent is passed on to the offspring by

A) homologous pairing.
B) meiosis and fertilization.
C) mitosis and cytokinesis.
D) karyotyping.
E) chiasmata.

Question 70

The sizes and shapes of chromosomes can be observed most easily in a cell that is in

A) prophase.
B) metaphase.
C) anaphase.
D) telophase.
E) cytokinesis.

Question 71

Diploid cells of the fruit fly Drosophila have ten chromosomes. How many chromosomes does a Drosophila gamete have?

A) 1
B) 2
C) 5
D) 10
E) 20

Question 72

Meiosis can occur

A) in all sexually reproducing organisms.
B) only when an organism is diploid.
C) only in multicellular organisms.
D) only in haploid organisms.
E) only in single-celled organisms.

Question 73

In all sexually reproducing organisms, the diploid phase of the life cycle begins at

A) spore formation.
B) gamete formation.
C) meiosis.
D) mitosis.
E) fertilization.

Question 74

All zygotes are

A) multicellular.
B) diploid.
C) animals.
D) clones.
E) gametes.

Question 75

The major drawback of asexual reproduction is that it

A) takes a great deal of time.
B) generates variation.
C) prevents change.
D) requires cytokinesis.
E) produces less variation among offspring than does sexual reproduction.

Question 76

The diagnosis of Down syndrome is made by examining the individual's

A) spores.
B) karyotype.
C) chromatin.
D) nucleosomes.
E) kinetochores.

Question 77

Each diploid cell of a human female contains _______ of each type of chromosome.

A) one
B) two
C) four
D) a total of 23
E) a total of 46

Question 78

The members of a homologous pair of chromosomes

A) are identical in size and appearance.
B) contain identical genetic information.
C) separate to opposite poles of the cell during mitosis.
D) are found only in haploid cells.
E) are present only after the S phase.

Question 79

Which of the following is not part of sexual reproduction?

A) The segregation of homologous chromosomes during gamete formation
B) The fusion of sister chromatids during fertilization
C) The fusion of haploid cells from a diploid zygote
D) The reduction in chromosome number during meiosis
E) The production of genetically distinct gametes during meiosis

Question 80

During meiosis, the sister chromatids separate during

A) anaphase II.
B) anaphase I.
C) the S phase.
D) synapsis.
E) telophase II.