Unit 5: Campbell Biology; Tenth Edition; Chapter 12; The Cell Cycle *MartinezCynthia*

Anaphase
the fourth stage of mitosis, in which the chromatids of each chromosome have separated and the daughter chromosomes are moving to the poles of the cell
Anchorage Dependence
the requirement that a cell must be attached to a substratum in order to initiate cell division
Benign Tumor
a mass of abnormal cells with specific genetic and cellular changes such that the cells are not capable of surviving at a new site and generally remain at the site of the tumor’s origin
Binary Fission
a method of asexual reproduction by “division in half.” — in prokaryotes, binary fission does not involve mitosis, but in single-celled eukaryotes that undergo binary fission, mitosis is part of the process
Cell Cycle
an ordered sequence of events in the life of a cell, from its origin in the division of a parent cell until its own division into two; the eukaryotic cell cycle is composed of interphase (including G1, S, and G2 subphases) and M phase (including mitosis and cytokinesis)
Cell Cycle Control System
a cyclically operating set of molecules in the eukaryotic cell that both triggers and coordinates key events in the cell cycle
Cell Division
the reproduction of cells
Cell Plate
a membrane-bounded, flattened sac located at the midline of a dividing plant cell, inside which the new cell wall forms during cytokinesis
Centromere
in a duplicated chromosome, the region on each sister chromatid where it is most closely attached to the other chromatid by proteins that bind to the centromeric DNA; other proteins condense the chromatin in that region, so it appears as a narrow “waist” on the duplicated chromosome; (an unduplicated chromosome has a single centromere, identified by the proteins bound there)
Centrosome
a structure present in the cytoplasm of animal cells that functions as a microtubule-organizing center and is important during cell division; a centrosome has two centrioles
Checkpoint
a control point in the cell cycle where stop and go-ahead signals can regulate the cycle
Chromatin
the complex of DNA and proteins that makes up eukaryotic chromosomes; when the cell is not dividing, chromatin exists in its dispersed form, as a mass of very long, thin fibers that are not visible with a light microscope
Chromosome
a cellular structure consisting of one DNA molecule and associated protein molecules; (in some contexts, such as genome sequencing, the term may refer to the DNA alone); a eukaryotic cell typically has multiple, linear chromosomes, which are located in the nucleus; a prokaryotic cell often has a single, circular chromosome, which is found in the nucleoid, a region that is not enclosed by a membrane; see also chromatin
Cleavage
(1) the process of cytokinesis in animal cells, characterized by pinching of the plasma membrane; (2) the succession of rapid cell divisions without significant growth during early embryonic development that converts the zygote to a ball of cells
Cleavage Furrow
the first sign of cleavage in an animal cell; a shallow groove around the cell in the cell surface near the old metaphase plate
Cyclin
a cellular protein that occurs in a cyclically fluctuating concentration and that plays an important role in regulating the cell cycle
Cyclin-Dependent Kinase (Cdk)
a protein kinase that is active only when attached to a particular cyclin
Cytokinesis
the division of the cytoplasm to form two separate daughter cells immediately after mitosis, meiosis I, or meiosis II
Density Dependent
referring to any characteristic that varies with population density
Density-Dependent Inhibition
the phenomenon observed in normal animal cells that causes them to stop dividing when they come into contact with one another
G0 Phase
a nondividing state occupied by cells that have left the cell cycle, sometimes reversibly
G1 Phase
the first gap, or growth phase, of the cell cycle, consisting of the portion of interphase before DNA synthesis begins
G2 Phase
the second gap, or growth phase, of the cell cycle, consisting of the portion of interphase after DNA synthesis occurs
Gamete
a haploid reproductive cell, such as an egg or sperm; gametes unite during sexual reproduction to produce a diploid zygote
Genome
the genetic material of an organism or virus; the complete complement of an organism’s or virus’s genes along with its noncoding nucleic acid sequences
Growth Factor
(1) a protein that must be present in the extracellular environment (culture medium or animal body) for the growth and normal development of certain types of cells; (2) a local regulator that acts on nearby cells to stimulate cell proliferation and differentiation
Interphase
the period in the cell cycle when the cell is not dividing; during interphase, cellular metabolic activity is high, chromosomes and organelles are duplicated, and cell size may increase; interphase often accounts for about 90% of the cell cycle
Kinetochore
a structure of proteins attached to the centromere that links each sister chromatid to the mitotic spindle
Malignant Tumor
a cancerous tumor containing cells that have significant genetic and cellular changes and are capable of invading and surviving in new sites; malignant tumors can impair the functions of one or more organs
Metaphase
the third stage of mitosis, in which the spindle is complete and the chromosomes, attached to microtubules at their kinetochores, are all aligned at the metaphase plate
Metaphase Plate
an imaginary structure located at a plane midway between the two poles of a cell in metaphase on which the centromeres of all the duplicated chromosomes are located
Metastasis
the spread of cancer cells to locations distant from their original site
Mitosis
a process of nuclear division in eukaryotic cells conventionally divided into five stages: prophase, prometaphase, metaphase, anaphase, and telophase; mitosis conserves chromosome number by allocating replicated chromosomes equally to each of the daughter nuclei
Mitotic (M) Phase
the phase of the cell cycle that includes mitosis and cytokinesis
Mitotic Spindle
an assemblage of microtubules and associated proteins that is involved in the movement of chromosomes during mitosis
MPF
maturation-promoting factor (or M-phase-promoting factor); a protein complex required for a cell to progress from late interphase to mitosis; the active form consists of cyclin and a protein kinase
Origin of Replication
site where the replication of a DNA molecule begins, consisting of a specific sequence of nucleotides
Prometaphase
the second stage of mitosis, in which the nuclear envelope fragments and the spindle microtubules attach to the kinetochores of the chromosomes
Prophase
the first stage of mitosis, in which the chromatin condenses into discrete chromosomes visible with a light microscope, the mitotic spindle begins to form, and the nucleolus disappears but the nucleus remains intact
S Phase
the synthesis phase of the cell cycle; the portion of interphase during which DNA is replicated
Sickle-Cell Disease
a recessively inherited human blood disorder in which a single nucleotide change in the ?-globin gene causes hemoglobin to aggregate, changing red blood cell shape and causing multiple symptoms in afflicted individuals
Sister Chromatids
two copies of a duplicated chromosome attached to each other by proteins at the centromere and, sometimes, along the arms; while joined, two sister chromatids make up one chromosome; chromatids are eventually separated during mitosis or meiosis II
Somatic Cell
any cell in a multicellular organism except a sperm or egg or their precursors
Telophase
the fifth and final stage of mitosis, in which daughter nuclei are forming and cytokinesis has typically begun
Transformation
(1) the conversion of a normal cell into a cell that is able to divide indefinitely in culture, thus behaving like a cancer cell; (malignant transformation may also describe the series of changes in a normal cell in an organism that change it into a malignant (cancerous) cell); (2) a change in genotype and phenotype due to the assimilation of external DNA by a cell; when the external DNA is from a member of a different species, transformation results in horizontal gene transfer
The person credited with first recognizing (in the 1860s) that living cells cannot arise spontaneously, but arise only from previously existing cells, is __________.

a. Anton van Leeuwenhoek
b. Rudolf Virchow
c. Robert Hooke
d. Louis Pasteur
e. Watson

Rudolf Virchow

In 1855 Rudolf Virchow stated, “Where a cell exists, there must have been a preexisting cell.”

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The function of the mitotic cell cycle is to produce daughter cells that __________.

a. have a random assortment of maternal and paternal chromosomes
b. have the same number of chromosomes as the parent cell but not the same genetic content
c. have the same number of chromatids as the parent cell had chromosomes
d. are genetically identical to the parent cell (assuming no mutation has occurred)
e. have none of the listed characteristics

are genetically identical to the parent cell (assuming no mutation has occurred)

Cell division involves the distribution of identical genetic material (DNA) to two daughter chromosomes.

Which of the following is FALSE regarding sister chromatids?

a. Both of the sister chromatids end up in the same daughter cell after cytokinesis has occurred.
b. Sister chromatids are created when DNA is replicated.
c. Sister chromatids are separated during mitosis.
d. Sister chromatids are attached to one another at the centromere.
e. Sister chromatids form in the S-phase stage of the cell cycle.

Both of the sister chromatids end up in the same daughter cell after cytokinesis has occurred.

This statement is false. Each of the sisters ends up in a different cell after cell division.

The complex of DNA and protein that makes up a eukaryotic chromosome is properly called __________.

a. a centromere
b. a chromoplast
c. a chromatid
d. chromatin
e. a centrosome

chromatin

The DNA-protein complex called chromatin is organized into a long, thin fiber.

The region of a chromosome in which the two double strands of replicated DNA are held together is called __________.

a. a centriole
b. an aster
c. chromatin
d. a chromatid
e. a centromere

a centromere

The chromosome has a narrow “waist” at a specialized region, called the centromere, where the two chromatids are attached to each other.

The centromere is a region in which __________.

a. chromosomes become aligned during metaphase
b. microtubules are fastened to the centrioles during anaphase
c. the new cell plate forms in telophase
d. the chromosomes are connected to the cell plate in metaphase
e. sister chromatids are attached to one another in prophase

sister chromatids are attached to one another in prophase

The chromosome has a narrow “waist” at a specialized region called the centromere, where sister chromatids are attached.

How many maternal chromosomes are present in a somatic human cell not engaged in cell division?

a. 23
b. 46
c. 92
d. 184
e. None of the listed responses is correct.

23

Human somatic cells contain a total of 46 chromosomes, half of which are maternally derived.

A cell entering the cell cycle with 32 chromosomes will produce two daughter cells, each with __________.

a. 16 chromosomes
b. 64 chromosomes
c. 32 pairs of chromosomes
d. 64 pairs of chromosomes
e. none of the listed numbers of chromosomes

none of the listed numbers of chromosomes

There would be 32 chromosomes present in each of the daughter cells.

“Cytokinesis” refers to __________.

a. the reduction in the number of chromosomes
b. the division of the entire cell
c. the division of the cytoplasm
d. the division of the nucleus
e. the movement of a cell from one place to another

the division of the cytoplasm

Cytokinesis is the division of the cytoplasm that follows the mitotic division of the nucleus.

Chromatids are __________.

a. held together by the centrioles
b. the bacterial equivalent of eukaryotic chromosomes
c. found only in aberrant chromosomes
d. composed of RNA
e. identical copies of each other if they are part of the same duplicated chromosome

identical copies of each other if they are part of the same duplicated chromosome

Each duplicated chromosome consists of two identical sister chromatids.

If a cell contains 60 chromatids at the start of mitosis, how many chromosomes will be found in each daughter cell at the completion of the cell cycle?

a. 15
b. 30
c. 45
d. 60
e. 120

30

In this case, mitosis starts with 30 chromosomes, each of which consists of two chromatids. At the completion of mitosis, each daughter cell will contain 30 chromosomes.

A biochemist measured the amount of DNA in cells growing in the laboratory and found that the quantity of DNA in the cells doubled __________.

a. between prophase and anaphase
b. between the G2 phase and prophase
c. between anaphase and telophase
d. during the M phase of the cell cycle
e. between the G1 and G2 phases

between the G1 and G2 phases

Between these two phases of the cell cycle, the DNA is replicated during the S phase.

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 at G1 of the cell cycle in one of the grasshopper daughter cells?

a. 50 units
b. 100 units
c. between 50 and 100 units
d. 200 units
e. 400 units

100 units

Recall that G2 follows S and that during the S phase, DNA is replicated.

During interphase, the genetic material of a typical eukaryotic cell is __________.

a. dispersed in the cytoplasm as long strands of chromatin
b. condensed and the chromosomes are often visible under the light microscope
c. dispersed in the nucleus as long strands of chromatin
d. attached to microtubule spindle fibers
e. transported through the nuclear pores

dispersed in the nucleus as long strands of chromatin

During interphase, the chromosomes cannot be distinguished individually because the chromosomes are still in the form of loosely packed chromatin fibers.

DNA replication occurs in __________.

a. cytokinesis
b. the G1 phase of interphase
c. the S phase of interphase
d. metaphase of mitosis
e. prophase of mitosis

the S phase of interphase

Chromosomes are duplicated only during the S phase (“S” stands for synthesis of DNA).

If a human somatic cell is just about to divide, it has __________ chromatids.

a. 0
b. 23
c. 46
d. 92
e. There is insufficient information to answer the question.

92

Human somatic cells have 92 chromatids just prior to cell division due to the replication of the 46 chromosomes that occurred during the S phase.

Down syndrome is characterized by cells having three copies of chromosome 21. As a cell in an individual with Down syndrome prepares to enter mitosis, how many chromatids would be present?

a. 23
b. 46
c. 92
d. 94
e. 98

94

Cells from an individual with Down syndrome would have 23 pairs of chromosomes, plus an extra chromosome for a total of 47. At S phase those chromosomes replicate to produce 94 sister chromatids.

Which of the following does NOT occur during mitosis?

a. separation of chromatids
b. condensation of chromatin
c. alignment of chromosomes along the cell’s equator
d. the movement of chromosomes to opposite poles
e. replication of chromosomes

replication of chromosomes

The DNA of the chromosomes is replicated in the S phase before mitosis.

During what phase in the cell cycle would you find the most DNA per cell?

a. S
b. S1
c. G1
d. G0
e. G2

G2

Chromosomes are duplicated only during the S phase (“S” stands for synthesis of DNA). The phase following completion of the S phase is G2.

In telophase of mitosis, the mitotic spindle breaks down and the chromatin uncoils. This is essentially the opposite of what happens in __________.

a. prophase
b. S phase
c. interphase
d. anaphase
e. metaphase

prophase

During prophase, we observe the formation of the spindle, the condensation of chromatin, and the disappearance of the nucleolus.

Which of the following phases of mitosis is essentially the OPPOSITE of prometaphase in terms of the nuclear envelope?

a. telophase
b. S phase
c. metaphase
d. anaphase
e. interphase

telophase

In prometaphase the nuclear envelope fragments and the kinetochores attach to microtubules. During telophase, fragments of the nuclear envelope begin to reassemble along with portions of the endomembrane system.

Assume that you are dealing with a species in which the number of chromosomes in each somatic cell is 14. How many sister chromatids are present in the early telophase of mitosis?

a. 0
b. 7
c. 14
d. 28
e. None of the listed responses is correct.

0

By telophase, the chromatids have separated and the individual units of DNA (now called chromosomes) are arriving at the poles. There are no chromatids at this point.

In a human skin cell that is going through the cell cycle, when do the centrosomes separate?

a. S phase
b. metaphase
c. prophase
d. G2 phase
e. anaphase

prophase

The centrosomes move away from each other during prophase, apparently propelled along the surface of the nucleus by the lengthening bundles of microtubules between them.

Following cytokinesis in an animal cell, how many centrioles does each new daughter cell possess?

a. zero
b. one
c. two
d. four
e. eight

two

Each daughter cell inherits a single centrosome following cytokinesis and each centrosome contains two centrioles.

The phase of mitosis during which the chromosomes move toward separate poles of the cell is __________.

a. prophase
b. metaphase
c. prometaphase
d. anaphase
e. telophase

anaphase

Anaphase begins when the cohesins joining sister chromatids are cleaved, allowing the chromatids (now called ‘chromosomes’) to move toward opposite poles of the cell.

One event occurring during prophase is __________.

a. the alignment of chromosomes in a single plane
b. the synthesis of a new nuclear envelope
c. the beginning of the formation of a spindle apparatus
d. the division of the centromere
e. cytokinesis

the beginning of the formation of a spindle apparatus

During prophase, the mitotic spindle begins to form.

Which event or events occur during anaphase?

a. Genetically identical chromosomes (previously sister chromatids) move to opposite poles during anaphase.
b. A spindle made of microtubules is present during anaphase.
c. Cohesins joining sister chromatids at the centromeres are cleaved during anaphase.
d. The centrioles are at opposite poles during anaphase.
e. All of the listed responses are correct.

All of the listed responses are correct.

Anaphase begins when the cohesins connecting sister chromatids are cleaved, liberating the chromatids (now called chromosomes), which begin moving toward opposite poles of the cell.

Which of the following represents a mismatch or incorrect description?

a. telophase: chromosomes become more extended
b. anaphase: there is movement of the chromosomes to the poles
c. metaphase: the nuclear envelope disappears
d. metaphase: chromosomes line up on the equatorial plane
e. prophase: chromosomes become more tightly coiled

metaphase: the nuclear envelope disappears

During prometaphase, the nuclear envelope fragments.

During which stage of the cell cycle do sister chromatids separate?

a. metaphase
b. anaphase
c. G1 phase
d. prophase
e. G2 phase

anaphase

Anaphase begins when the cohesins joining sister chromatids are cleaved, allowing the chromatids (now called chromosomes) to move toward opposite poles of the cell.

In animal cell mitosis, the cleavage furrow forms during which stage of the cell cycle?

a. metaphase
b. the G1 phase
c. anaphase
d. cytokinesis
e. prophase

cytokinesis

Cytokinesis is usually well under way by telophase. In animal cells, cytokinesis involves the formation of a cleavage furrow, which pinches the cell in two.

At which stage of mitosis are chromosomes lined up in one plane in preparation for their separation to opposite poles of the cell?

a. telophase
b. interphase
c. metaphase
d. prophase
e. anaphase

metaphase

The chromosomes convene on the metaphase plate, an imaginary plane that is equidistant from the spindle’s two poles.

You would know that a dividing cell was a plant cell rather than an animal cell if you saw that __________.

a. it had formed a cleavage furrow
b. it had microtubules
c. it had two pairs of centrioles during prophase
d. the nucleolus was visible during metaphase
e. it had formed a cell plate

it had formed a cell plate

The cell plate, which divides the cytoplasm in two, forms during the telophase of mitosis in a plant cell.

Which of the following processes does NOT occur in dividing bacteria?

a. binary fission
b. mitosis
c. inward growth of the plasma membrane
d. replication of DNA
e. separation of the origins of replication

mitosis

Mitosis does not occur in dividing bacteria. Mitosis might have had its origins in simpler bacterial mechanisms of cell reproduction. Prokaryotes (bacteria) reproduce by a type of cell division called binary fission.

During binary fission in a bacterium, __________.

a. the two DNA molecules attach to the centrioles
b. the two DNA molecules divide in half, forming four DNA fragments
c. the two DNA molecules break up into plasmids
d. the origins of replication move apart
e. the two DNA molecules float free in the cell and are guided to daughter cells by a spindle-like apparatus

the origins of replication move apart

This occurs during binary fission.

Which of the following is involved in the binary fission of most bacteria?

a. distribution of a copy of the single parental chromosome to each daughter cell
b. formation of a cell plate
c. disintegration of the nuclear membrane
d. formation of a spindle apparatus
e. prophase, prometaphase, metaphase, anaphase, and telophase

distribution of a copy of the single parental chromosome to each daughter cell

Prokaryotes reproduce by a type of cell division called binary fission, which involves replicating the single chromosome and distributing the copies equally to two daughter cells.

When a cell in S phase is fused with a cell in G1, __________.

a. the original G1 cell will divide immediately
b. the two nuclei fuse and additional division is arrested
c. the replication of DNA occurring in the original S nucleus is terminated
d. DNA synthesis begins immediately in the original G1 nucleus
e. the chromosomes of the original G1 nucleus condense in preparation for mitosis

DNA synthesis begins immediately in the original G1 nucleus

This observation indicates that cytoplasmic signals can participate in the regulation of the cell cycle.

Tissue culture experiments with PDGF demonstrate that without this substance __________.

a. bacterial cells lose their resistance to antibiotics
b. fibroblasts fail to divide
c. the various kinases, such as MPF, are unable to bind to cyclin
d. animal cells are unable to attach to the substratum
e. cells divide in an uncontrolled fashion, confirming PDGF’s role as a cell division inhibitor

fibroblasts fail to divide

PDGF is a specific growth factor for fibroblasts.

You would be UNLIKELY to see which of the following human cells dividing?

a. skin cell
b. cell from an embryo
c. cancer cell
d. nerve cell
e. All of these cell types are equally unlikely to divide at any given time.

nerve cell

Nerve cells are quite complex and specialized. After reaching maturity, they enter the G0 phase.

Which of the following hypotheses is best supported by observing cancer cells in a culture?

a. The cancer cells exhibit anchorage dependence.
b. The cancer cells spend the majority of their time in the G0 phase.
c. The cancer cells do not exhibit density-dependent inhibition.
d. The cancer cells produce molecules that inhibit the growth factors required for cell division.
e. All of the listed responses are correct.

The cancer cells do not exhibit density-dependent inhibition.

Normal cells respond to density-dependent inhibition by growing in culture to form a single layer of cells.

What is the difference between a benign tumor and a malignant tumor?

a. Benign tumors will not kill you; malignant tumors will.
b. Benign tumors arise by transformation; malignant tumors do not.
c. Benign tumors do not arise by transformation; malignant tumors do.
d. Cells of benign tumors do not metastasize; those of malignant tumors do.
e. Cells of benign tumors metastasize; those of malignant tumors do not.

Cells of benign tumors do not metastasize; those of malignant tumors do.

Cells of malignant tumors spread from their site of origin to other parts of the body.

Through a microscope, you can see a cell plate beginning to develop across the middle of a cell and nuclei forming on either side of the cell plate. This cell is most likely

a. a bacterial cell dividing.
b. an animal cell in the process of cytokinesis.
c. a plant cell in the process of cytokinesis.
d. a plant cell in metaphase.
e. an animal cell in the S phase of the cell cycle.

a plant cell in the process of cytokinesis.
Vinblastine is a standard chemotherapeutic drug used to treat cancer. Because it interferes with the assembly of micro-tubules, its effectiveness must be related to

a. inhibition of regulatory protein phosphorylation.
b. myosin denaturation and inhibition of cleavage furrow formation.
c. disruption of mitotic spindle formation.
d. suppression of cyclin production.
e. inhibition of DNA synthesis.

disruption of mitotic spindle formation.
One difference between cancer cells and normal cells is that cancer cells

a. are always in the M phase of the cell cycle.
b. are unable to synthesize DNA.
c. continue to divide even when they are tightly packed together.
d. cannot function properly because they are affected by density-dependent inhibition.
e. are arrested at the S phase of the cell cycle.

continue to divide even when they are tightly packed together.
The decline of MPF activity at the end of mitosis is due to

a. synthesis of DNA.
b. the degradation of cyclin.
c. the destruction of the protein kinase Cdk.
d. the accumulation of cyclin.
e. decreased synthesis of Cdk.

the degradation of cyclin.
In the cells of some organisms, mitosis occurs without cytoki-nesis. This will result in

a. cells lacking nuclei.
b. destruction of chromosomes.
c. cells that are unusually small.
d. cell cycles lacking an S phase.
e. cells with more than one nucleus.

cells with more than one nucleus.
Which of the following does not occur during mitosis?

a. separation of the spindle poles
b. separation of sister chromatids
c. replication of the DNA
d. spindle formation
e. condensation of the chromosomes

replication of the DNA
A particular cell has half as much DNA as some other cells in a mitotically active tissue. The cell in question is most likely in

a. metaphase.
b. G1.
c. anaphase.
d. prophase.
e. G2.

G1.
The drug cytochalasin B blocks the function of actin. Which of the following aspects of the animal cell cycle would be most disrupted by cytochalasin B?

a. spindle attachment to kinetochores
b. cell elongation during anaphase
c. DNA synthesis
d. spindle formation
e. cleavage furrow formation and cytokinesis

cleavage furrow formation and cytokinesis
A double stranded chromosome consists of genetically identical sister chromatids.

a. True
b. False

True
Your inherited traits are determined by genes located on your chromosomes.

a. True
b. False

True
Human somatic cells wouldl have the characteristic chromosome number of 46 chromosomes.

a. True
b. False

True
If there are 20 chromatids in a cell, how many centromeres are there?

a. 10
b. 20
c. 30
d. 40
e. 80

10
By the end of this phase the nuclear envelope has fragmented or disapears, the nucleoli disappear, and the spindle fibers have attached to the double stranded chromosomes.

a. Prophase
b. Metaphase
c. Anaphase
d. Telophase

Prophase
What is a chromatid?

a. a chromosome in G1 of the cell cycle
b. a replicated 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

a replicated chromosome
Which term describes centromeres uncoupling, sister chromatids separating, and the two single stranded chromosomes moving to opposite poles of the cell?

a. telophase
b. anaphase
c. metaphase
d. prophase

anaphase
Which is the longest of the mitotic stages?

a. telophase
b. anaphase
c. metaphase
d. prophase

metaphase
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.

The daughter cells have the same number of chromosomes and the same amount of DNA.
The formation of a cell plate is beginning across the middle of a cell and nuclei are re-forming at opposite ends of the cell. What kind of cell is this?

a. an animal cell in metaphase
b. an animal cell in telophase
c. an animal cell undergoing cytokinesis
d. a plant cell in metaphase
e. a plant cell undergoing cytokinesis

a plant cell undergoing cytokinesis
In order for anaphase to begin, which of the following must occur?

a. Chromatids must lose their kinetochores.
b. Cohesin must attach the sister chromatids to each other.
c. Cohesin must be cleaved enzymatically.
d. Kinetochores must attach to the metaphase plate.
e. Spindle microtubules must begin to depolymerize.

Cohesin must be cleaved enzymatically.
Only cancer cells are actively dividing cells in the adult human body.

a. True
b. False

False
Why do chromosomes coil during mitosis?

a. to increase their potential energy
b. to allow the chromosomes to move without becoming entangled and breaking
c. to allow the chromosomes to fit within the nuclear envelope
d. to allow the sister chromatids to remain attached
e. to provide for the structure of the centromere

to allow the chromosomes to move without becoming entangled and breaking
The process that converts a normal cell into a cancer cell is called…

a. Cytokinesis
b. Oogenesis
c. Transformation
d. Metastasis

Transformation
If a cell has 8 chromosomes at metaphase of mitosis, how many chromosomes will it have during anaphase?

a. 1
b. 2
c. 4
d. 8
e. 16

16
Which of the following is a false statement?

a. Normal cells complete a limited number of divisions before they age and die.
b. Cancer cells can be metastatic if they have abnormal changes on their cell surfaces.
c. Normal human cells have a characteristic number of chromosomes.
d. Cancer cells have the ability to stimulate blood vessels to grow towards the tumor.
e. Normal cells are better able to repair DNA damaged by high energy radiation.
f. All of the above are correct.
g. All of the above are false.

All of the above are correct.
Imagine looking through a microscope at a squashed onion root tip. The chromosomes of many of the cells are plainly visible. In some cells, replicated chromosomes are aligned along the center (equator) of the cell. These particular cells are in which stage of mitosis?

a. telophase
b. prophase
c. anaphase
d. metaphase

metaphase
Cancer cells lack density-dependent inhibition and anchorage dependence.

a. True
b. False

True
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.

prevents shortening of microtubules.
Cytokinesis usually, but not always, follows mitosis. If a cell completed mitosis but not cytokinesis, the result would be a cell with

a. a single large nucleus.
b. high concentrations of actin and myosin.
c. two abnormally small nuclei.
d. two nuclei.
e. two nuclei but with half the amount of DNA.

two nuclei.