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The Cell Cycle -72 Questions with Answers - Cell Biology | BIOL 127, Study notes of Cell Biology

ch12 testbank Material Type: Notes; Class: Cell Biology; Subject: Biology; University: Lansing Community College; Term: Spring 2011;

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Chapter12 TheCellCycle
Multiple-ChoiceQuestions
1) Thecentromereisaregioninwhich
A) chromatidsremainattachedtooneanotheruntilanaphase.
B) metaphasechromosomesbecomealignedatthemetaphaseplate.
C) chromosomesaregroupedduringtelophase.
D) thenucleusislocatedpriortomitosis.
E) newspindlemicrotubulesformateitherend.
Answer: A
Topic: Concept12.1
Skill: Knowledge/Comprehension
2) Whatisachromatid?
A) achromosomeinG1ofthecellcycle
B) areplicatechromosome
C) achromosomefoundoutsidethenucleus
D) aspecialregionthatholdstwocentromerestogether
E) anothernameforthechromosomesfoundingenetics
Answer: B
Topic: Concept12.1
Skill: Knowledge/Comprehension
3) Startingwithafertilizedegg(zygote),aseriesoffivecelldivisionswouldproduceanearlyembryowithhow
manycells?
A) 4
B) 8
C) 16
D) 32
E) 64
Answer: D
Topic: Concept12.1
Skill: Application/Analysis
4) Ifthereare20chromatidsinacell,howmanycentromeresarethere?
A) 10
B) 20
C) 30
D) 40
E) 80
Answer: A
Topic: Concept12.1
Skill: Application/Analysis
5) Foranewlyevolvingprotist,whatwouldbetheadvantageofusingeukaryote -likecelldivisionratherthan
binaryfission?
A) Binaryfissionwouldnotallowfortheformationofneworganisms.
B) Celldivisionwouldallowfortheorderlyandefficientsegregationofmultiplelinearchromosomes.
C) Celldivisionwouldbefasterthanbinaryfission.
D) Celldivisionallowsforlowerratesoferrorperchromosomereplication.
E) Binaryfissionwouldnotallowtheorganismtohavecomplexcells.
Answer: B
Topic: Concept12.1
Skill: Synthesis/Evaluation
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Download The Cell Cycle -72 Questions with Answers - Cell Biology | BIOL 127 and more Study notes Cell Biology in PDF only on Docsity!

Chapter 12 The Cell Cycle

Multiple-Choice Questions

  1. The centromere is a region in which A) chromatids remain attached to one another until anaphase. B) metaphase chromosomes become aligned at the metaphase plate. C) chromosomes are grouped during telophase. D) the nucleus is located prior to mitosis. E) new spindle microtubules form at either end. Answer: A Topic: Concept 12. Skill: Knowledge/Comprehension

  2. What is a chromatid? A) a chromosome in G1 of the cell cycle B) a replicate chromosome C) a chromosome found outside the nucleus D) a special region that holds two centromeres together E) another name for the chromosomes found in genetics Answer: B Topic: Concept 12. Skill: Knowledge/Comprehension

  3. Starting with a fertilized egg (zygote), a series of five cell divisions would produce an early embryo with how many cells? A) 4 B) 8 C) 16 D) 32 E) 64 Answer: D Topic: Concept 12. Skill: Application/Analysis

  4. If there are 20 chromatids in a cell, how many centromeres are there? A) 10 B) 20 C) 30 D) 40 E) 80 Answer: A Topic: Concept 12. Skill: Application/Analysis

  5. For a newly evolving protist, what would be the advantage of using eukaryote - like cell division rather than binary fission? A) Binary fission would not allow for the formation of new organisms. B) Cell division would allow for the orderly and efficient segregation of multiple linear chromosomes. C) Cell division would be faster than binary fission. D) Cell division allows for lower rates of error per chromosome replication. E) Binary fission would not allow the organism to have complex cells. Answer: B Topic: Concept 12. Skill: Synthesis/Evaluation

  1. How do the daughter cells at the end of mitosis and cytokinesis compare with their parent cell when it was in G1 of the cell cycle? A) The daughter cells have half the amount of cytoplasm and half the amount of DNA. B) The daughter cells have half the number of chromosomes and half the amount of DNA. C) The daughter cells have the same number of chromosomes and half the amount of DNA. D) The daughter cells have the same number of chromosomes and the same amount of DNA. E) The daughter cells have the same number of chromosomes and twice the amount of DNA. Answer: D Topic: Concepts 12. Skill: Knowledge/Comprehension

Use the following information to answer the questions below.

The lettered circle in Figure 12.1 shows a diploid nucleus with four chromosomes. There are two pairs of homologous chromosomes, one long and the other short. One haploid set is symbolized as black and the other haploid set is gray. The chromosomes in the unlettered circle have not yet replicated. Choose the correct chromosomal conditions for the following stages.

Figure 12.

  1. at prometaphase of mitosis Answer: B Topic: Concept 12. Skill: Knowledge/Comprehension

  2. one daughter nucleus at telophase of mitosis Answer: E Topic: Concept 12. Skill: Knowledge/Comprehension

  1. A cell containing 92 chromatids at metaphase of mitosis would, at its completion, produce two nuclei each containing how many chromosomes? A) 12 B) 16 C) 23 D) 46 E) 92 Answer: D Topic: Concept 12. Skill: Application/Analysis

Figure 12.

  1. If the cell whose nuclear material is shown in Figure 12.2 continues toward completion of mitosis, which of the following events would occur next? A) cell membrane synthesis B) spindle fiber formation C) nuclear envelope breakdown D) formation of telophase nuclei E) synthesis of chromatids Answer: D Topic: Concept 12. Skill: Knowledge/Comprehension

  2. If there are 20 centromeres in a cell at anaphase, how many chromosomes are there in each daughter cell following cytokinesis? A) 10 B) 20 C) 30 D) 40 E) 80 Answer: B Topic: Concept 12. Skill: Application/Analysis

  1. If there are 20 chromatids in a cell at metaphase, how many chromosomes are there in each daughter cell following cytokinesis? A) 10 B) 20 C) 30 D) 40 E) 80 Answer: A Topic: Concepts 12.1, 12. Skill: Application/Analysis

Use the data in Table 12.1 to answer the following questions.

The data were obtained from a study of the length of time spent in each phase of the cell cycle by cells of three eukaryotic organisms designated beta, delta, and gamma.

Cell Type G1 S G2 M Beta 18 24 12 16 Delta 100 0 0 0 Gamma 18 48 14 20

Table 12.1: Minutes Spent in Cell Cycle Phases

  1. Of the following, the best conclusion concerning the difference between the S phases for beta and gamma is that A) gamma contains more DNA than beta. B) beta and gamma contain the same amount of DNA. C) beta contains more RNA than gamma. D) gamma contains 48 times more DNA and RNA than beta. E) beta is a plant cell and gamma is an animal cell. Answer: A Topic: Concept 12. Skill: Application/Analysis

  2. The best conclusion concerning delta is that the cells A) contain no DNA. B) contain no RNA. C) contain only one chromosome that is very short. D) are actually in the G0 phase. E) divide in the G1 phase. Answer: D Topic: Concept 12. Skill: Application/Analysis

  3. Where do the microtubules of the spindle originate during mitosis in both plant and animal cells? A) centromere B) centrosome C) centriole D) chromatid E) kinetochore Answer: B Topic: Concept 12. Skill: Knowledge/Comprehension

  1. Taxol is an anticancer drug extracted from the Pacific yew tree. In animal cells, taxol disrupts microtubule formation by binding to microtubules and accelerating their assembly from the protein precursor, tubulin. Surprisingly, this stops mitosis. Specifically, taxol must affect A) the fibers of the mitotic spindle. B) anaphase. C) formation of the centrioles. D) chromatid assembly. E) the S phase of the cell cycle. Answer: A Topic: Concept 12. Skill: Application/Analysis

  2. Which of the following are primarily responsible for cytokinesis in plant cells? A) kinetochores B) Golgi-derived vesicles C) actin and myosin D) centrioles and basal bodies E) cyclin-dependent kinases Answer: B Topic: Concept 12. Skill: Knowledge/Comprehension

  3. Chromosomes first become visible during which phase of mitosis? A) prometaphase B) telophase C) prophase D) metaphase E) anaphase Answer: C Topic: Concept 12. Skill: Knowledge/Comprehension

  4. During which phases of mitosis are chromosomes composed of two chromatids? A) from interphase through anaphase B) from G1 of interphase through metaphase C) from metaphase through telophase D) from anaphase through telophase E) from G2 of interphase through metaphase Answer: E Topic: Concept 12. Skill: Knowledge/Comprehension

  5. In which group of eukaryotic organisms does the nuclear envelope remain intact during mitosis? A) seedless plants B) dinoflagellates C) diatoms D) B and C only E) A, B, and C Answer: D Topic: Concept 12. Skill: Knowledge/Comprehension

  1. Movement of the chromosomes during anaphase would be most affected by a drug that A) reduces cyclin concentrations. B) increases cyclin concentrations. C) prevents elongation of microtubules. D) prevents shortening of microtubules. E) prevents attachment of the microtubules to the kinetochore. Answer: D Topic: Concept 12. Skill: Synthesis/Evaluation

  2. Measurements of the amount of DNA per nucleus were taken on a large number of cells from a growing fungus. The measured DNA levels ranged from 3 to 6 picograms per nucleus. In which stage of the cell cycle was the nucleus with 6 picograms of DNA? A) G B) G C) S D) G E) M Answer: D Topic: Concept 12. Skill: Application/Analysis

  3. A group of cells is assayed for DNA content immediately following mitosis and is found to have an average of 8 picograms of DNA per nucleus. Those cells would have __________ picograms at the end of the S phase and __________ picograms at the end of G 2. A) 8; 8 B) 8; 16 C) 16; 8 D) 16; 16 E) 12; 16 Answer: D Topic: Concept 12. Skill: Application/Analysis

  4. The somatic cells derived from a single-celled zygote divide by which process? A) meiosis B) mitosis C) replication D) cytokinesis alone E) binary fission Answer: B Topic: Concept 12. Skill: Knowledge/Comprehension

  1. What is the most probable hypothesis about these intermediate forms of cell division? A) They represent a form of cell reproduction which must have evolved completely separately from those of other organisms. B) They demonstrate that these species are not closely related to any of the other Protists and may well be a different Kingdom. C) They rely on totally different proteins for the processes they undergo. D) They may be more closely related to plant forms that also have unusual mitosis. E) They show some of the evolutionary steps toward complete mitosis but not all. Answer: E Topic: Concept 12. Skill: Synthesis/Evaluation

  2. Which of the following best describes how chromosomes move toward the poles of the spindle during mitosis? A) The chromosomes are ʺreeled inʺ by the contraction of spindle microtubules. B) Motor proteins of the kinetochores move the chromosomes along the spindle microtubules. C) Non-kinetochore spindle fibers serve to push chromosomes in the direction of the poles. D) both A and B E) A, B, and C Answer: B Topic: Concept 12. Skill: Knowledge/Comprehension

  3. Which of the following is a function of those spindle microtubules that do not attach to kinetochores? A) maintaining an appropriate spacing among the moving chromosomes B) producing a cleavage furrow when telophase is complete C) providing the ATP needed by the fibers attached to kinetochores D) maintaining the region of overlap of fibers in the cellʹs center E) pulling the poles of the spindles closer to one another Answer: D Topic: Concept 12. Skill: Synthesis/Evaluation

Use the following to answer the questions below.

Nucleotides can be radiolabeled before they are incorporated into newly forming DNA and can therefore be assayed to track their incorporation. In a set of experiments, a student-faculty research team used labeled T nucleotides and introduced these into the culture of dividing human cells at specific times.

  1. Which of the following questions might be answered by such a method? A) How many cells are produced by the culture per hour? B) What is the length of the S phase of the cell cycle? C) When is the S chromosome synthesized? D) How many picograms of DNA are made per cell cycle? E) When do spindle fibers attach to chromosomes? Answer: B Topic: Concept 12. Skill: Synthesis/Evaluation
  1. The research team used the setup to study the incorporation of labeled nucleotides into a culture of lymphocytes and found that the lymphocytes incorporated the labeled nucleotide at a significantly higher level after a pathogen was introduced into the culture. They concluded that A) the presence of the pathogen made the experiment too contaminated to trust the results. B) their tissue culture methods needed to be relearned. C) infection causes lymphocytes to divide more rapidly. D) infection causes cell cultures in general to reproduce more rapidly. E) infection causes lymphocyte cultures to skip some parts of the cell cycle. Answer: C Topic: Concept 12. Skill: Synthesis/Evaluation

  2. If mammalian cells receive a go-ahead signal at the G1 checkpoint, they will

A) move directly into telophase. B) complete the cycle and divide. C) exit the cycle and switch to a nondividing state. D) show a drop in MPF concentration. E) complete cytokinesis and form new cell walls. Answer: B Topic: Concept 12. Skill: Knowledge/Comprehension

  1. Cells that are in a nondividing state are in which phase? A) G B) G C) G D) S E) M Answer: A Topic: Concept 12. Skill: Knowledge/Comprehension

  2. What causes the decrease in the amount of cyclin at a specific point in the cell cycle? A) an increase in production once the restriction point is passed B) the cascade of increased production once its protein is phosphorylated by Cdk C) the changing ratio of cytoplasm to genome D) its destruction by a process initiated by the activity of its complex with a cyclin E) the binding of PDGF to receptors on the cell surface Answer: D Topic: Concept 12. Skill: Knowledge/Comprehension

  3. Which of the following is released by platelets in the vicinity of an injury? A) PDGF B) MPF C) protein kinase D) cyclin E) Cdk Answer: A Topic: Concept 12. Skill: Knowledge/Comprehension

  1. This is the shortest part of the cell cycle: A) G B) G C) S D) G E) M Answer: E Topic: Concept 12. Skill: Knowledge/Comprehension

  2. DNA is replicated at this time of the cell cycle: A) G B) G C) S D) G E) M Answer: C Topic: Concept 12. Skill: Knowledge/Comprehension

  3. The ʺrestriction pointʺ occurs here: A) G B) G C) S D) G E) M Answer: B Topic: Concept 12. Skill: Knowledge/Comprehension

  4. Nerve and muscle cells are in this phase: A) G B) G C) S D) G E) M Answer: A Topic: Concept 12. Skill: Knowledge/Comprehension

  5. The cyclin component of MPF is destroyed toward the end of this phase: A) G B) G C) S D) G E) M Answer: E Topic: Concept 12. Skill: Knowledge/Comprehension

The following questions are based on Figure 12.3.

Figure 12.

  1. In the figure above, mitosis is represented by which number? A) I B) II C) III D) IV E) V Answer: D Topic: Concept 12. Skill: Application/Analysis

  2. G1 is represented by which number(s)? A) I and V B) II and IV C) III D) IV E) V Answer: A Topic: Concept 12. Skill: Application/Analysis

  3. Which number represents DNA synthesis? A) I B) II C) III D) IV E) V Answer: B Topic: Concept 12. Skill: Application/Analysis

  1. A mutation results in a cell that no longer produces a normal protein kinase for the M phase checkpoint. Which of the following would likely be the immediate result of this mutation? A) The cell would prematurely enter anaphase. B) The cell would never leave metaphase. C) The cell would never enter metaphase. D) The cell would never enter prophase. E) The cell would undergo normal mitosis, but fail to enter the next G1 phase. Answer: E Topic: Concept 12. Skill: Application/Analysis

  2. Density-dependent inhibition is explained by which of the following? A) As cells become more numerous, they begin to squeeze against each other, restricting their size and ability to produce control factors. B) As cells become more numerous, the cell surface proteins of one cell contact the adjoining cells and they stop dividing. C) As cells become more numerous, the protein kinases they produce begin to compete with each other, such that the proteins produced by one cell essentially cancel those produced by its neighbor. D) As cells become more numerous, more and more of them enter the S phase of the cell cycle. E) As cells become more numerous, the level of waste products increases, eventually slowing down metabolism. Answer: B Topic: Concept 12. Skill: Knowledge/Comprehension

  3. Which of the following is true concerning cancer cells? A) They do not exhibit density-dependent inhibition when growing in culture. B) When they stop dividing, they do so at random points in the cell cycle. C) They are not subject to cell cycle controls. D) B and C only E) A, B, and C Answer: E Topic: Concept 12. Skill: Knowledge/Comprehension

  4. Which of the following describe(s) cyclin-dependent kinase (Cdk)? A) Cdk is inactive, or ʺturned off,ʺ in the presence of cyclin. B) Cdk is present throughout the cell cycle. C) Cdk is an enzyme that attaches phosphate groups to other proteins. D) Both A and B are true. E) Both B and C are true. Answer: E Topic: Concept 12. Skill: Knowledge/Comprehension

  1. A particular cyclin called cyclin E forms a complex with a cyclin-dependent kinase called Cdk 2. This complex is important for the progression of the cell from G1 into the S phase of the cell cycle. Which of the following statements is correct? A) The amount of cyclin E is greatest during the S phase. B) The amount of Cdk 2 is greater during G1 compared to the S phase. C) The amount of cyclin E is highest during G1. D) The amount of Cdk 2 is greatest during G1. E) The activity of the cyclin E/Cdk 2 complex is highest during G 2. Answer: C Topic: Concept 12. Skill: Application/Analysis

  2. The research team established similar lymphocyte cultures from a number of human donors, including healthy teenagers of both genders, patients already suffering from long - term bacterial infections, and elderly volunteers. They found that the increase in lymphocyte incorporation after pathogen introduction was slightly lower in some of the women teenagers and significantly lower in each of the elderly persons. They repeated the study with a larger number of samples but got the same results. What might be among their conclusions? A) The young women showed these results because they have poorer nutrition. B) The elderly personsʹ samples demonstrated their lowered immune responses. C) The young men had higher response because they are generally healthier. D) The patient samples should have had the lowest response but did not, so the experiment is invalid. E) The elderly donor samples represent cells no longer capable of any cell division. Answer: B Topic: Concept 12. Skill: Synthesis/Evaluation

  3. Cells from an advanced malignant tumor most often have very abnormal chromosomes, and often an abnormal total number of chromosomes. Why might this occur? A) Cancer cells are no longer density dependent. B) Cancer cells are no longer anchorage dependent. C) Chromosomally abnormal cells can still go through cell cycle checkpoints. D) Chromosomally abnormal cells still have normal metabolism. E) Transformation introduces new chromosomes into cells. Answer: C Topic: Concept 12. Skill: Synthesis/Evaluation

  4. Besides the ability of some cancer cells to overproliferate, what else could logically result in a tumor? A) metastasis B) changes in the order of cell cycle stages C) lack of appropriate cell death D) inability to form spindles E) inability of chromosomes to meet at the metaphase plate Answer: C Topic: Concept 12. Skill: Synthesis/Evaluation

  1. The drug cytochalasin B blocks the function of actin. Which of the following aspects of the cell cycle would be most disrupted by cytochalasin B? A) spindle formation B) spindle attachment to kinetochores C) DNA synthesis D) cell elongation during anaphase E) cleavage furrow formation Answer: E Topic: Skill:

  2. In the cells of some organisms, mitosis occurs without cytokinesis. This will result in A) cells with more than one nucleus. B) cells that are unusually small. C) cells lacking nuclei. D) destruction of chromosomes. E) cell cycles lacking an S phase. Answer: A Topic: Skill:

  3. Which of the following does not occur during mitosis? A) condensation of the chromosomes B) replication of the DNA C) separation of sister chromatids D) spindle formation E) separation of the spindle poles Answer: B Topic: Skill: