Question 1

In meiosis, recombination occurs:

Accepted Answer

A)  during prophase I and II and involves exchange of chromosome fragments between all four chromatids.
B)  only during prophase I and involves exchange between chromatids of homologous chromosomes.
C)  only during prophase I and involves exchange of chromosome fragments between sister chromatids.
D)  during prophase I and II and involves exchange of chromosome fragments between sister chromatids.

Question 2

What would happen if crossing over occurred between sister chromatids?

Accepted Answer

A)  Genetic diversity would decrease due to the loss of gene combinations.
B)  Genetic diversity would increase due to the addition of gene combinations.
C)  Gene rearrangement would lead to changes in gene expression.
D)  Nothing would happen because sister chromatids are genetically identical or nearly identical.

Question 3

The CORRECT sequence of steps in the M phase of the cell cycle is:

Accepted Answer

A)  prophase, prometaphase, metaphase, anaphase, telophase, nuclear division.
B)  prophase, prometaphase, metaphase, anaphase, telophase, cytokinesis.
C)  prophase, metaphase, prometaphase, anaphase, nuclear division, telophase.
D)  prophase, metaphase, anaphase, telophase, cytokinesis, nuclear division.

Question 4

In what way is cytokinesis in plant cells similar to binary fission in a bacterium?

Accepted Answer

A)  Cell wall material is deposited to separate the daughter cells.
B)  A ring of actin filaments constricts the plasma membrane between the two nuclei to separate the daughter cells.
C)  A microtubulin-like structure constricts the plasma membrane between the two nuclei to separate the daughter cells.
D)  A motor protein slides microtubules in a contractile ring at the plasma membrane between the two nuclei to separate the daughter cells.
E)  All of these choices are correct.

Question 5

Studies of rapidly dividing embryonic animal cells revealed:

Accepted Answer

A)  a cyclic production of certain proteins in sync with the cell cycle.
B)  a cyclic activation of protein kinases in sync with the cell cycle.
C)  that the production of cyclin proteins is followed by activation of CDK enzymes.
D)  that inhibition of protein production blocks mitosis.
E)  All of these choices are correct.

Question 6

Synapsis is best described as the:

Accepted Answer

A)  exchange of genetic information between sister chromatids.
B)  alignment of non-sister chromatids at the metaphase plate.
C)  exchange of genetic information between non-sister chromatids.
D)  pairing of homologous chromosomes in prophase I.

Question 7

In which phase of mitosis does the mitotic spindle form?

Accepted Answer

A)  prophase
B)  metaphase
C)  anaphase
D)  telophase

Question 8

The M cyclin-CDK complex:

Accepted Answer

A)  controls the cell cycle during the M phase.
B)  initiates many events of mitosis.
C)  triggers phosphorylation of certain nuclear proteins, resulting in breakdown of the nuclear envelope during prophase.
D)  phosphorylates proteins that promote formation of the mitotic spindle.
E)  All of these choices are correct.

Question 9

Many of the specific functions that are triggered when a cell passes one of the cell cycle checkpoints result from activation of enzymes and other proteins. A common mechanism for this activation is:

Accepted Answer

A)  phosphorylation of specific proteins.
B)  signal transduction.
C)  polymerization of tubulin.
D)  ATP synthesis.

Question 10

Which of the following steps in prokaryotic binary fission is CORRECT?

Accepted Answer

A)  DNA is replicated bidirectionally from a single point on the circular chromosome.
B)  The two replicated chromosomes remain attached to the plasma membrane.
C)  The cell continues to grow outward symmetrically, separating the two chromosomes.
D)  Cell wall material is laid down at the midpoint to separate the two daughter cells.
E)  All of these choices are correct.

Question 11

Most of the significant changes in activities and functions that accompany passage through a cell cycle checkpoint are regulated by the:

Accepted Answer

A)  activation of microtubules.
B)  changes in membrane polarization.
C)  activation of kinase enzymes.
D)  activation of DNA polymerase.
E)  inhibition of cyclin proteins.

Question 12

Which of the following is NOT a hallmark of malignant cancer?

Accepted Answer

A)  Cell division in the absence of growth signals.
B)  Resistance to signals that slow cell division or promote death.
C)  Metastasis, which allows invasion of local tissues.
D)  Ability to stimulate growth of blood vessels to provide nutrients to the rapidly growing tumor.
E)  All of these choices are hallmarks of cancer.

Question 13

Recall the experiments of Rous and colleagues. If he had found that filtered cancer cell extract could not cause cancer when injected into healthy animals, what could he have deduced?

Accepted Answer

A)  Cancer may be caused by bacteria.
B)  An intact cancer cell is necessary to cause cancer.
C)  A large protein may cause cancer.
D)  All of these choices are correct.

Question 14

Polar bodies are:

Accepted Answer

A)  haploid cells.
B)  functional gametes that are produced by meiosis.
C)  produced by mitosis.
D)  functional gametes that are produced by mitosis.

Question 15

Which of the following statements regarding tumor suppressors is TRUE?

Accepted Answer

A)  Tumor suppressors promote cell division.
B)  Tumor suppressors act synergistically with proto-oncogenes.
C)  Mutations affecting tumor suppressors can contribute to the development of cancers.
D)  Tumor suppressors include PDGF and cyclins.
E)  None of the other answer options is correct.

Question 16

Why don't plant cells use a contractile ring to divide their daughter cells?

Accepted Answer

A)  Plant cells don't have an actin cytoskeleton.
B)  Plant cells don't form daughter cells.
C)  A contractile ring can't "pinch" a cell wall.
D)  Plant cells don't have plasma membranes.

Question 17

Which of the following is circled in this electron micrograph?  Photo credit: Biophoto Associates/Science Source

Accepted Answer

A)  one double-stranded DNA molecule
B)  one single strand of a DNA molecule
C)  two double-stranded DNA molecules

Question 18

All of the following happen during mitosis EXCEPT:

Accepted Answer

A)  condensing of chromosomes.
B)  synthesis of DNA.
C)  formation of the spindle.
D)  separation of sister chromatids at the centromeres.

Question 19

A phragmoplast functions to:

Accepted Answer

A)  stimulate the growth of the microtubule spindle.
B)  anchor microtubules to sister chromatids.
C)  break down the nuclear envelope.
D)  form a new cell wall.

Question 20

What would happen if a chromosome only connected to the mitotic spindle at one of its kinetochores?

Accepted Answer

A)  One of the daughter cells would have an extra copy of that chromosome.
B)  The sister chromatids would not separate.
C)  The chromosome would not line up properly at metaphase.
D)  All of these choices are correct.

Exam 11: Cell Division: Variations, Regulation, and Cancer

Recall the experiments of Rous and colleagues. If he had found that filtered cancer cell extract could not cause cancer when injected into healthy animals, what could he have deduced?

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Why don't plant cells use a contractile ring to divide their daughter cells?

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Studies of rapidly dividing embryonic animal cells revealed:

Correct AnswerverifiedShow Answer

The CORRECT sequence of steps in the M phase of the cell cycle is:

Correct AnswerverifiedShow Answer

Most of the significant changes in activities and functions that accompany passage through a cell cycle checkpoint are regulated by the:

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All of the following happen during mitosis EXCEPT:

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In meiosis, recombination occurs:

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Which of the following is circled in this electron micrograph? Photo credit: Biophoto Associates/Science Source

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Which of the following steps in prokaryotic binary fission is CORRECT?

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Which of the following statements regarding tumor suppressors is TRUE?

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In what way is cytokinesis in plant cells similar to binary fission in a bacterium?

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In which phase of mitosis does the mitotic spindle form?

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Polar bodies are:

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The M cyclin-CDK complex:

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Synapsis is best described as the:

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Which of the following is NOT a hallmark of malignant cancer?

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Many of the specific functions that are triggered when a cell passes one of the cell cycle checkpoints result from activation of enzymes and other proteins. A common mechanism for this activation is:

Correct AnswerverifiedShow Answer

A phragmoplast functions to:

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What would happen if a chromosome only connected to the mitotic spindle at one of its kinetochores?

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What would happen if crossing over occurred between sister chromatids?

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