Deck 10: Chromosomes, Mitosis, and Meiosis

Question 1

A cell is dividing by binary fission. What can you conclude?

A) Mitosis has taken place without cytokinesis.
B) Homologous chromosomes have already paired.
C) The cyclin-Cdk complex is no longer phosphorylating enzymes.
D) The cell is undergoing uncontrolled cell division.
E) The cell is prokaryotic.

Answer 1

E

Question 2

What is not a hallmark of prophase?

A) Nuclear envelope is visible with the light microscope.
B) Nucleolus disappears.
C) Mitotic spindle is beginning to assemble.
D) Spindle fibers pull chromosomes to opposite sides of the cell.
E) Duplicated chromosomes become visible with the light microscope.

Answer 2

D

Question 3

Duplicated centrioles move to opposite poles of a dividing ____ cell during the ____ of the cell cycle.

A) plant; metaphase
B) plant; anaphase
C) prokaryotic; metaphase
D) animal; interphase
E) animal; prophase

Answer 3

E

Question 4

Cytokinesis in animal cells involves contraction of a ring of ____ microfilaments.

A) tubulin plus actin
B) actin plus myosin
C) cyclin plus myosin
D) cohesin plus actin
E) cyclin plus actin

Question 5

When is a cell in metaphase?

A) The chromosomes are visible as threadlike structures.
B) The nuclear envelope is clearly visible.
C) The chromosomes are aligned at the midplane of the cell.
D) The chromosomes are separated into distinct groups at opposite cell poles.
E) Cytokinesis is occurring.

Question 6

A bacterial chromosome consists of a

A) linear DNA molecule many times larger than the cell.
B) circular DNA molecule many times larger than the cell.
C) circular DNA molecule smaller than the cell.
D) linear DNA molecule smaller than the cell.
E) linear or circular DNA molecule smaller than the cell.

Question 7

In unwound chromatin, nucleosomes are organized into large coiled loops held together by

A) histones.
B) centromeres.
C) kinetochore proteins.
D) scaffolding proteins.
E) condensins.

Question 8

Which of the following are surrounded by fibrils that make up the pericentriolar material?

A) Mitotic spindle
B) Centrioles
C) Kinetochore
D) Microtubules
E) Centromere

Question 9

____ ______________organized on chromosomes carry the information that controls the functions of the cell.

A) Proteins
B) Nucleosomes
C) Asters
D) Genes
E) Histones

Question 10

The cell cycle of a typical somatic cell consists of the ____ and M phases.

A) interphase
B) meiosis I
C) crossing-over
D) meiosis II
E) mitosis

Question 11

What is the function of kinetochores?

A) Kinetochores anchor spindle fibers to the centrioles.
B) Kinetochores are the site of DNA synthesis.
C) Kinetochores regulate the length of the cell cycle.
D) Kinetochores attach to microtubules during mitosis.
E) Kinetochores are involved in cytokinesis.

Question 12

Eukaryotic chromosomes consist of

A) circular DNA molecules complexed with positively charged nonhistone proteins.
B) circular DNA molecules complexed with negatively charged histone proteins.
C) linear DNA molecules complexed with positively charged histone proteins.
D) linear DNA molecules complexed with negatively charged histone proteins.
E) circular DNA molecules folded to fit inside a bacterial cell.

Question 13

The function of nucleosomes is to

A) prevent DNA strands from tangling.
B) help DNA replicate.
C) make RNA synthesis possible.
D) prevent RNA from tangling with DNA during transcription.
E) prevent histones from tangling.

Question 14

The ____ is responsible for the separation of the chromosomes during the ____ of mitosis.

A) cell wall; anaphase
B) mitotic spindle; interphase
C) mitotic spindle; anaphase
D) kinetochore; prophase
E) centromere; telophase

Question 15

Nucleosomes are best described as

A) eukaryotic DNA associated with histone proteins.
B) prokaryotic DNA associated with nonhistone proteins.
C) eukaryotic DNA associated with nonhistone proteins.
D) prokaryotic DNA associated with histone proteins.
E) eukaryotic DNA associated with scaffolding proteins.

Question 16

The mitotic spindle is made of

A) motor proteins.
B) condensin.
C) histones.
D) Z rings.
E) microtubules.

Question 17

Eukaryotic chromosomes are composed of

A) proteins only.
B) chromatin.
C) DNA only.
D) circular chromatin.
E) karyotypes.

Question 18

During prophase, ____ is(are) compacted into visible chromosomes.

A) chromatin
B) centrioles
C) centromeres
D) kinetochores
E) tetrads

Question 19

____ contain identical DNA sequences and are held together by ____ during mitosis.

A) Daughter chromosomes; hydrogen bonding
B) Daughter chromosomes; ionic bonding
C) Sister chromatids; spindle fibers
D) Sister chromosomes; histone proteins
E) Sister chromatids; cohesin proteins

Question 20

Cytokinesis in plant cells occurs via the formation of a(n)

A) aster.
B) mitotic spindle.
C) Golgi complex.
D) cell wall.
E) cell plate.

Question 21

To control the cell cycle,

A) the activity of Cdks stays the same throughout the cell cycle.
B) cyclins fluctuate during the cell cycle.
C) Cdks are active only when they are released from cyclins.
D) the anaphase-promoting complex stimulates DNA replication.
E) M-Cdk inhibits mitosis.

Question 22

Homologous chromosomes undergo synapsis during

A) anaphase I.
B) prophase I.
C) anaphase II.
D) telophase II.
E) prophase II.

Question 23

During which stage of meiosis do the sister chromatids separate?

A) Metaphase I
B) Anaphase I
C) Metaphase II
D) Anaphase II
E) telophase II

Question 24

Figure 10-1 ​

​
Which phase of cell division is depicted in the accompanying figure?

A) Prophase of mitosis
B) Metaphase of mitosis
C) Prophase I of meiosis
D) Prophase II of meiosis
E) Metaphase I of meiosis

Question 25

During prophase I of meiosis, homologous chromosomes lie side by side. This phenomenon is known as

A) chromatid pairing.
B) DNA replication.
C) tetrad formation.
D) paternal pairing.
E) parental pairing.

Question 26

A cell in the G₂ phase

A) has twice the amount of DNA present in a telophase nucleus.
B) has visibly distinct chromosomes.
C) lacks a visible nuclear membrane.
D) is in mitosis.
E) is in cytokinesis.

Question 27

Homologous chromosomes can be identified and/or characterized by

A) their similar and characteristic staining patterns.
B) the different centromere positions in the maternal versus paternal chromosomes.
C) those chromosomes that do not have partners.
D) paternal chromosomes only.
E) maternal chromosomes only.

Question 28

What evolutionary advantage is provided by sexual reproduction?

A) Increased genetic diversity
B) Generation of clones
C) Production of genetically identical offspring
D) Possibility of polyploidy in the progeny
E) Removal of all genetic mutations

Question 29

Plant hormones known as ____ stimulate mitosis.

A) scaffolding proteins
B) growth factors
C) cytokinins
D) cyclins
E) cohesins

Question 30

Once nerve cells become mature, they do not typically undergo cell division. Based on your knowledge of the cell cycle, you might predict that mature nerve cells become arrested in the ____ of the cell cycle.

A) G₀ phase
B) S phase
C) prophase
D) G₁ phase
E) G₂ phase

Question 31

Chromosomes are duplicated during the ____ of the cell cycle.

A) G₁ phase
B) G₂ phase
C) S phase
D) metaphase
E) prophase

Question 32

Which of the following is produced by meiosis?

A) Somatic cells
B) Animal gametes
C) Polyploid cells
D) Diploid cells
E) Zygotes

Question 33

Figure 10-1 ​

​
In the accompanying figure, which combination of letters accurately represents two homologous chromosomes?

A) A and B
B) A and C
C) A and D
D) B and F
E) D and E

Question 34

During prophase I, each chiasma represents

A) the remnants of the nuclear envelope.
B) the remnant of the nucleolus.
C) a newly formed haploid gamete.
D) a site of crossing-over.
E) the site where sister chromatids are connected.

Question 35

In a human cell at prophase I, there are ____ tetrads.

A) 92
B) 46
C) 23
D) 2
E) 4

Question 36

The M phase of the cell cycle involves two main processes:

A) mitosis and cytokinesis.
B) meiosis I and meiosis II.
C) homologous pairing and crossing over.
D) interphase and mitosis.
E) mitosis and meiosis.

Question 37

To prevent disastrous consequences, the eukaryotic cell cycle is controlled by

A) the mitochondria.
B) replication.
C) environmental signals.
D) a very detailed, rigid genetic program.
E) a series of cell cycle checkpoints.

Question 38

An animal with a diploid number of 36 chromosomes will have ____ chromosomes in its gametes and ____ chromosomes in its somatic cells.

A) 18; 18
B) 18; 36
C) 36; 18
D) 36; 36
E) 36; 72

Question 39

What would happen if meiosis did not occur in sexually reproducing organisms?

A) The growth of the zygote would be halted.
B) Mitosis would be sufficient to produce haploid gametes.
C) The gametes would remain haploid.
D) The chromosome number would double in each generation.
E) The eggs would be haploid, but the sperm would be diploid.

Question 40

Figure 10-1 ​

​
In the accompanying figure, which combination of letters accurately represents two sister chromatids?

A) A and B
B) A and C
C) A and D
D) A and E
E) B and F

Question 41

Microtubules of the mitotic spindle attach directly to each chromosome at the centromere.
​

Question 42

An animal zygote is a haploid cell.

Question 43

In fungi and protists, gametes produced by ____ of haploid cells fuse to form a ____ zygote, which then undergoes ____ to restore the haploid chromosome number.

A) mitosis, diploid, meiosis
B) meiosis, diploid, mitosis
C) mitosis, haploid, meiosis
D) meiosis, haploid, mitosis
E) mitosis, diploid, mitosis

Question 44

Briefly describe the advantages of asexual reproduction of unicellular organisms.

Question 45

Briefly explain the difference between meiosis I and mitosis. Also, explain the reasons for these differences.

Question 46

Cell-cycle checkpoints temporarily block key events from being initiated during the cell cycle.

Question 47

Figure 10-2 ​

​
The process occurring at arrow 3 in the accompanying figure is

A) fertilization.
B) G₁.
C) meiosis.
D) mitosis.
E) fusion.

Question 48

The nuclear envelope fragments during the prometaphase stage.

Question 49

At the completion of oogenesis, ____ are produced.

A) male gametes
B) four sperm cells
C) four egg cells
D) one egg cell and three polar bodies
E) haploid spores

Question 50

List the stages in the eukaryotic cell cycle, and identify the principal events that occur during each stage.

Question 51

In the cell cycle, DNA is replicated during the G₂ phase.

Question 52

Homologous pairs of chromosomes separate during meiosis I.

Question 53

Enzymes required for DNA replication are synthesized during the G₁ phase.

Question 54

Draw and label the parts of a sister chromatid. List the function of each structure.

Question 55

A nucleosome consists of DNA wrapped around scaffolding proteins.

Question 56

A pair of centrioles is found at the center of the microtubule-organizing center in plant cells.

Question 57

In animal cells, cytokinesis occurs via the formation of a cell plate.

Question 58

Gametophyte plants produce gametes using

A) mitosis.
B) meiosis.
C) fertilization.
D) polyploidy.
E) sporogenesis.

Question 59

Bacteria divide asexually by mitosis.

Question 60

Which event occurs in prophase II?

A) Disappearance of the spindle
B) Condensation of the chromatin into chromosomes
C) Formation of the chiasmata
D) Crossing over occurs.
E) Formation of the cleavage furrow

Question 64

For each animal cell that begins oogenesis, the number of ova produced is four.

Question 69

Sketch the life cycle of a plant and label the ploidy of each stage. You may use n to represent the haploid number of chromosomes.

Question 71

Why do the cells produced by meiosis undergo two nuclear divisions but only have a haploid number of chromosomes?

Question 76

Briefly describe how the cell cycle is controlled and why phosphorylation of proteins plays a major role.