Deck 9: Cell Division

Question 1

Cancers are groups of cells that divide rapidly and uncontrollably. Thus cancer cells

A) are always in the G0 phase.
B) never enter the cell cycle.
C) probably have a very short G1 phase.
D) are stuck at the metaphase plate.

Answer 1

C

Question 2

The G₀ phase of the cell cycle is distinguished by

A) an active preparation for DNA synthesis.
B) a doubling of chromosomes.
C) an absence of preparation for DNA synthesis.
D) the appearance of a metaphase plate.

Answer 2

C

Question 3

The two sister chromatids of a single chromosome are held together by a

A) centrosome.
B) spindle fiber.
C) centromere.
D) chromatin.

Answer 3

C

Question 4

Chromosomes are lined up at the middle of the cell during the _______ portion of cell division.

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

Question 5

Which of the following series correctly represents the levels of DNA packing from simplest to most dense?

A) DNA strand ® chromatin ® chromosomes
B) Chromosome ® chromatin ® DNA strand
C) Chromosome ® chromatin ® DNA
D) Chromatin ® DNA ® centromere

Question 6

A single cell grows into a multicellular organism by the process of

A) mitosis.
B) meiosis.
C) fertilization.
D) duplication.

Question 7

Which of the following statements is not generally true?

A) As an organism matures, it needs more cells.
B) As an organism matures, it needs different kinds of cells.
C) As an organism matures, it needs to replace the DNA in each of its cells.
D) As an organism matures, it needs to replace worn-out cells.

Question 8

Which set of symbols represents the stages of interphase?

A) G0, G1, and G2
B) S1, S2, and G0
C) S, G0, and G1
D) S, G1, and G2

Question 9

Cell division, the climax of the cell cycle, consists of

A) chromosome replication and separation.
B) the breakup of the nucleus at the metaphase plate.
C) mitosis or meiosis.
D) the formation of a new karyotype.

Question 10

Which of the following must occur before cell division begins?

A) duplication of the nucleus
B) DNA synthesis
C) cytokinesis
D) DNA segregation

Question 11

Which of the following statements about cell division is correct?

A) It is the process by which organisms grow and maintain their tissues.
B) It is no longer necessary once an organism reaches maturity.
C) It occurs in two sequential stages in all cells: mitosis and meiosis.
D) It is the process by which fertilization occurs.

Question 12

The mitotic spindle is made of

A) centrosomes.
B) chromosomes.
C) kinetochores.
D) microtubules.

Question 13

The microtubules that grow out from the centrosomes

A) pull the nuclear envelope apart.
B) pull the centrosomes together.
C) eventually become kinetochores.
D) eventually attach to centromeres.

Question 14

Which of the following choices states a correct reason why the process of cell division is different for prokaryotic than for eukaryotic cells?

A) Prokaryotes have a circular DNA molecule.
B) Prokaryotic cells do not undergo cell division.
C) Prokaryotic cells are larger than eukaryotic cells.
D) Prokaryotic DNA contains different bases from those in eukaryotic DNA.

Question 15

Which of the following is true of the chromosomes in a homologous pair?

A) They both came from the organism's mother.
B) They both came from the organism's father.
C) One chromosome came from each of the organism's parents.
D) Neither chromosome came from the organism's parents.

Question 16

The process of mitosis is thought to have evolved from binary fission. What similarities exist between these processes?

A) The DNA being separated is attached to a membrane during both processes.
B) Both processes involve the separation of more than one piece of DNA.
C) Both processes include DNA segregation.
D) DNA must be tightly packaged into chromosomes before either process can begin.

Question 17

The completion of the physical division of the parent cell during the last stage of mitosis is known as

A) centrosome formation.
B) G0.
C) cytokinesis.
D) meiosis.

Question 18

The goal of mitosis is to

A) form two equal daughter nucleii.
B) form chromatin strands.
C) loop chromatin into chromosomes.
D) package chromosomes into chromatin.

Question 19

An unduplicated chromosome contains

A) two sister chromatids.
B) a single molecule of DNA.
C) the cell's karyotype.
D) its own spindle poles.

Question 20

During the S phase, the cell

A) duplicates its DNA.
B) grows in size to prepare for DNA synthesis.
C) completes its preparation for mitosis.
D) rests between divisions.

Question 21

The parent cell shown below left undergoes meiosis. In the box, lettered A through C, are three different gametes.
Which of these gametes could have come from this parent cell?

A) Gamete A
B) Gamete B
C) Gamete C
D) All of these gametes could have come from this parent cell.

Question 22

By the time a cell enters meiosis II, it has

A) become haploid.
B) re-formed bivalents.
C) become temporarily diploid.
D) rejoined its maternal homologue.

Question 23

The reduction division of meiosis has occurred when

A) bivalents are cut in half by proteins in their centromeres.
B) half of the bivalents line up on each side of the metaphase plate.
C) the first cell division of meiosis is complete.
D) the second cell division of meiosis is complete.

Question 24

Plants perform cytokinesis differently than animals because

A) plant cytokinesis takes place during interphase but animal cytokinesis takes place in cell division.
B) plant chromosomes are more difficult to separate than animal chromosomes.
C) the rigid cell wall of the plant cell prevents the plasma membrane from pinching inward like it does in animal cells.
D) the centrosomes of plants do not replicate prior to cell division.

Question 25

The successful union of one male and one female gamete forms a new single cell known as a

A) histone.
B) zygote.
C) vesicle.
D) T cell.

Question 26

If a plant has a karyotype of 18 chromosomes, how many chromosomes would be present in each of its gametes?

A) 36
B) 18
C) 9
D) 6

Question 27

Gametes contain _________ the genetic material that a generalized body cell contains.

A) half
B) the same amount of
C) twice
D) four times

Question 28

Which of the following foods is most likely to contain haploid cells?

A) a sirloin steak
B) an apple
C) an egg
D) a stalk of celery

Question 29

During anaphase I of meiosis,

A) sister chromatids are pulled apart toward opposite poles.
B) each member of a bivalent moves toward a different pole.
C) all bivalents are pulled to the same pole.
D) paired homologues become attached to each other by microtubules.

Question 30

Meiosis I is called a reduction division because the

A) need for mitosis is reduced.
B) time it takes for the cell to divide is reduced.
C) chromosome number goes from diploid to haploid.
D) cell size is reduced.

Question 31

At the completion of mitosis, the nucleus of a human somatic cell has ___ chromosomes.

A) 23
B) 46
C) 92
D) 184

Question 32

Why must DNA be packed into chromosomes before mitosis or meiosis can occur?

A) In their unpacked state, the strands of DNA would be difficult to pull apart during cell division.
B) The zygote would be unable to live if the DNA were not packed into chromosomes.
C) We would be unable to see the karyotype if the DNA were not packed into chromosomes.
D) Some of the genes would escape during cell division if they were not packed tightly into chromosomes.

Question 33

Only meiosis could lead to the production of new

A) skin cells.
B) brain cells.
C) sperm cells.
D) liver cells.

Question 34

After a single cell undergoes meiosis, how many new cells will be produced?

A) 2
B) 4
C) 12
D) 16

Question 35

When examining the rapidly dividing cells of the onion root tip, you see a cell whose chromosomes are visible and are arranged in approximately the same size and shape as the nucleus. What stage of mitosis is this cell in?

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

Question 36

When examining the rapidly dividing cells of a fish embryo, you notice a cell that seems to contain two nuclei. The middle of the cell is pinched inward. This cell must be in _____ of mitosis.

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

Question 37

A drug inhibits the formation of microtubules. This drug is added to a culture of cells during G₂. How might this drug affect the cell division?

A) Cytokinesis could not occur.
B) The nuclear envelope would be unable to break down.
C) DNA synthesis would not occur.
D) The spindle apparatus would be unable to form.

Question 38

The fact that DNA is distributed into homologous pairs allows

A) cells to reduce their chromosome number by half during meiosis.
B) a cell to begin meiosis with only one half of its DNA.
C) sex chromosomes to exist in some cells.
D) microtubules to attach to only half of the chromosomes.

Question 39

How many sister chromatids are in a bivalent?

A) 2
B) 4
C) 8
D) 16

Question 40

During anaphase, daughter chromosomes

A) are condensed into chromatin.
B) move toward opposite spindle poles.
C) form homologous pairs.
D) move toward the same spindle pole.

Question 41

Induced pluripotent stem cells (iPS) differ from embryonic stem cells (hES) because

A) iPS cells are made with viruses rather than being harvested from an embryo
B) iPS cells exhibit the same properties as hES cells but are made from adult somatic cells rather than embryonic cells.
C) hES cells have the same DNA as their recipient and are less likely to be rejected than iPS cells.
D) hES cells are more highly differentiated than iPS cells.

Question 42

Chromosomes become visible during the _______ stage of mitosis.

Question 43

Microtubules attach to plaques of protein called ______________ on chromosomes.

Question 44

Sister chromatids are held together at a constriction point called a ____________.

Question 45

Lily plants sometimes have twice as many chromosomes per cell as their parent plants had. Which of the following explains how this might have happened?

A) The lily's sister chromatids failed to separate during meiosis.
B) The chromosome number of the lily went from 2n to 1n.
C) The lily gametes fused during mitosis.
D) The parent plant lost half of its chromosomes during mitosis.

Question 46

The bivalents of homologous chromosomes undergo crossing over. What is the significance of this process?

A) Two copies of the same chromosome are allowed to become part of the same gamete.
B) The resulting gametes will have different gene combinations than their parent cells' gene combinations.
C) The bivalent chromosomes are able to exchange genetic material with other pairs of chromosomes.
D) The gametes that are produced will have twice as many chromosomes as the parent cells had.

Question 47

Adult stem cells differ from embryonic stem cells in that

A) embryonic stem cells are found throughout the body of the fetus, but adult stems cells are found only in adults.
B) adult stem cells are easier to obtain than embryonic stem cells.
C) adult stem cells can differentiate into fewer types of cells than embryonic stem cells.
D) embryonic stem cells do not require differentiation signals like adult stem cells do.

Question 48

The attachment of microtubules to the centromeres of chromosomes during ____________ of mitosis sets the stage for the positioning of the chromosomes at the metaphase plate.

Question 49

Huge amounts of DNA (6 feet in humans) can fit into the nucleus of a single cell because the DNA is wrapped around ________ to form a "beaded necklace" know as chromatin.

Question 50

The cell depicted below has a diploid number of 4 (2n = 4).
Assuming cell division started with a diploid cell, in what stage of what type of cell division is the cell?

A) anaphase of mitosis
B) anaphase I of meiosis
C) anaphase II of meiosis
D) Both A and C are possible.

Question 51

At the end of telophase the cell is ready for physical division into two cells, a process called ___________.

Question 52

The most critical stage of interphase for a cell that needs to undergo cell division is ________ phase. If the cell does not complete this phase, it cannot undergo DNA segregation.

Question 53

As the _____________ separate during prophase, they determine opposite ends, or spindle poles, of a cell that is beginning mitosis.

Question 54

The spindle microtubules break down and new nuclear envelopes form during the _______ portion of mitosis.

Question 55

The goal of __________ is to increase genetic diversity by creating a new diploid individual from haploid cells.

Question 56

DNA ____________ is essential to cell division because it separates the two copies of DNA attached by the centromere.

Question 57

During mitosis, the number and shape of an organism's chromosomes become obvious. This set of identifiable chromosomes can be arranged into a diagram, or _______, of that organism.

Question 58

The cell depicted below has a diploid number of 8 (2n = 8).
Assuming cell division started with a diploid cell, in what stage of what type of cell division is the cell?

A) anaphase of mitosis
B) anaphase I of meiosis
C) anaphase II of meiosis
D) Both A and C are possible.

Question 59

A somatic cell contains 16 chromosomes. The diploid number of this cell is _________ [2n = ?].

Question 60

Gametes are produced by meiosis rather than mitosis because

A) mitosis would produce too many sister cells.
B) meiosis reduces the chromosome number so that zygotes produced will have one full genome.
C) meiosis doubles the chromosome number so that each gamete has twice the usual number of genes.
D) meiosis ensures that the gametes are identical to the cell that produced them.

Question 61

New nuclei form during the anaphase portion of cell division.

Question 62

The daughter cells of meiosis I are haploid.

Question 63

All cells in a human body undergo the process of meiosis.

Question 64

The sequence of events in meiosis II is prophase II, ____________, anaphase II, and telophase II, then cytokinesis.

Question 65

Meiosis I is almost identical to the events in mitosis.

Question 66

Cytokinesis occurs during interphase.

Question 67

The four cells that result from meiosis are _________ rather than diploid.

Question 68

During meiosis I, the microtubules from only one spindle pole attach to only one member of a bivalent.

Question 69

A special feature of _______ cells is that they retain their ability to divide throughout the life of the organism in which they reside.

Question 70

The random distribution of chromosomes into daughter cells during ____________ of meiosis is one way to create genetic diversity.

Question 71

Both meiosis I and meiosis II decrease the number of chromosomes found in a cell.

Question 72

Unlike mitosis, the nuclear membrane doesn't break down in meiosis II.

Question 73

A drug inhibits the formation of vesicles from the Golgi apparatus. How might this drug affect the cell cycle of a plant cell?

Question 74

The mitotic spindle guides the movement of chromosomes during certain stages of mitosis.

Question 75

Interphase is an uneventful resting stage of the cell division cycle.

Question 76

If the skin cell of an organism has 24 chromosomes, its gametes must also have 24 chromosomes.

Question 77

Cytokinesis and mitosis are the same processes.