Deck 7: Cell Division

Question 1

The goal of mitosis is to

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

Answer 1

A

Question 2

Which of the following statements about cell division is true?

A) It is the process by which organisms grow and maintain their tissues.
B) It is no longer necessary after 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.

Answer 2

A

Question 3

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

A) DNA strand → chromatin → chromosome
B) chromosome → chromatin → DNA strand
C) DNA strand → chromosome → chromatin
D) chromatin → DNA strand → centromere

Answer 3

A

Question 4

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

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

Question 5

Which set of symbols represents the stages of interphase?

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

Question 6

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

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

Question 7

In what way does a human somatic cell differ from a human gamete?

A) Somatic cells are diploid (n), whereas gametes are haploid (2n).
B) Somatic cells are created by meiosis, whereas gametes are created by mitosis.
C) Somatic cells differentiate into at least 220 cell types, whereas there are only two types of gametes.
D) Somatic cells can spontaneously change into gametes, but gametes must remain gametes.

Question 8

Which of the following statements about why multicellular organisms need cell division is generally NOT 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 9

The G₀ phase of the cell cycle is distinguished by

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

Question 10

What feature distinguishes an embryo from a zygote?

A) An embyro's cells are diploid, whereas a zygote's cells are haploid.
B) A zygote consists of a single cell, whereas an embryo is multicellular.
C) An embryo has not differentiated to the extent that rudimentary organs are present, whereas a zygote's cells have differentiated significantly.
D) A zygote is generally much larger than an embryo.

Question 11

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

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

Question 12

Which of the following statements is a correct reason why the process of cell division in prokaryotes is different from cell division in eukaryotes?

A) Prokaryotes have a circular DNA molecule; eukaryotes have linear DNA molecules in their nuclei.
B) Prokaryotic cells do not undergo cell division, and eukaryotic cells do.
C) Prokaryotic cells are larger than eukaryotic cells.
D) Prokaryotic DNA contains bases that are different from those in eukaryotic DNA.

Question 13

Sexual reproduction results in many benefits for a population,but also some inconveniences.Which of the following statements is NOT an example of an inconvenience of sexual reproduction?

A) Each participant in sexual reproduction must locate an appropriate mate.
B) The time required for sexual reproduction may mean that short-term opportunities for population growth via asexual reproduction will be missed.
C) Some genetic combinations may be disadvantageous and/or lethal for offspring, and the effort invested in producing offspring would therefore be wasted.
D) Sexual reproduction with each reproductive event is more likely to result in too many offspring for the species.

Question 14

Cancers are groups of cells that divide uncontrollably because they

A) are always in the G0 phase.
B) never enter the cell cycle.
C) are unable to respond to the negative internal or external signals that keep the cell from dividing.
D) are stuck at the metaphase plate.

Question 15

Which of the following processes must occur before cell division begins?

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

Question 16

Biologists believe the process of mitosis evolved from binary fission.What are the similarities between these two processes?

A) In both processes, the DNA that is being separated is attached to a membrane.
B) Both processes necessarily 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

During the S phase,the cell

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

Question 18

Some human cells (skeletal muscle,for example)are multinucleated and originate when uninucleated cells fuse.What cell division process alone could produce a multinucleated cell?

A) a cell undergoing mitosis but not cytokinesis
B) a cell undergoing cytokinesis but not mitosis
C) a cell arresting after meiosis I
D) fertilization of a haploid egg by a diploid sperm

Question 19

Sexual and asexual reproduction can both offer distinct advantages under certain circumstances.In which of the following situations would asexual reproduction NOT be advantageous?

A) Decomposers discover a dolphin carcass that has recently drifted to the ocean floor.
B) A persistently cooling climate results in a significant increase in average winter snow depth.
C) A cut breaches the skin's defensive ability, and infectious pathogens invade the injury.
D) Coastal currents, water temperature, nutrient concentrations, and light intensity temporarily combine to produce ideal growth conditions for marine phytoplankton.

Question 20

Some daughter cells are called clones; for this description to be accurate,the daughter cells must

A) show the same differentiation characteristics as the parent cell.
B) separate from each other and exist independently.
C) contain a set of DNA that is identical to that of the parent cell.
D) have been produced by meiotic cell division.

Question 21

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

A) histone.
B) zygote.
C) vesicle.
D) gametocyte.

Question 22

An unduplicated chromosome contains

A) two sister chromatids.
B) a single molecule of double-stranded DNA combined with a large number of proteins.
C) the cell's karyotype.
D) its own spindle poles.

Question 23

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

A) 36
B) 18
C) nine
D) six

Question 24

If a drug that inhibits the formation of microtubules is added to a culture of cells during the G₂ phase,how would the cell division be affected?

A) Cytokinesis would occur more rapidly.
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 25

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

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

Question 26

Which of the following statements about the microtubules that grow out from the centrosomes is true?

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

Question 27

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

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

Question 28

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

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

Question 29

You are examining the rapidly dividing cells of a fish embryo and notice a cell that seems to contain two nuclei with complete nuclear envelopes and decondensing chromosomes.The middle of the cell is pinched inward.This cell must be in

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

Question 30

Plant cells perform cytokinesis differently than animal cells because

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

Question 31

The mitotic spindle is made of

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

Question 32

After a single cell undergoes meiosis in a male,how many sperm cells will be produced?

A) two
B) four
C) 12
D) 16

Question 33

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

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

Question 34

Gametes are produced by meiosis rather than mitosis because

A) mitosis would produce too many sister cells.
B) meiosis reduces the number of chromosomes so that the zygotes resulting from fertilization will have one full genome consisting of a diploid number of chromosomes.
C) meiosis doubles the number of chromosomes 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 35

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

A) a sirloin steak
B) an apple
C) one or more chicken eggs
D) a stalk of celery

Question 36

The completion of the physical division of the parent cell cytoplasm that usually occurs during the last stage of mitosis is known as

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

Question 37

Chromosomes are lined up at the middle of the cell during the phase of cell division called

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

Question 38

Which of the following things could NOT be determined from looking at a karyotype?

A) the gender of the individual who provided the sample
B) whether the source of the sample was a nonhuman species
C) whether the source of the sample was a somatic cell or a gamete
D) the height and eye color of the individual who provided the sample

Question 39

In animals,only meiosis can lead to the production of new ________.

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

Question 40

During anaphase,daughter chromosomes do which of the following things?

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

Question 41

A process essential to cell division because it separates the two copies of DNA that are attached by the centromere is called DNA ________.

Question 42

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 43

When appropriately prompted,diploid individuals of Ulva prolifera form spores that germinate to become haploid individuals.What is the most likely mechanism by which diploid individuals could be created to complete the life cycle?

A) Haploid individuals meiotically produce egg cells and sperm cells, which subsequently fuse.
B) Some haploid individuals undergo multiple rounds of mitosis without cytokinesis, followed by nuclear fusion.
C) Some of these individuals differentiate to become haploid gametes and then fuse to produce a diploid zygote.
D) Haploid individuals undergo two sequential S phases in their cell cycle to reestablish the diploid state.

Question 44

Compared with the amount of genetic material in a generalized body cell,gametes contain

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

Question 45

During mitosis,the number and shape of an organism's chromosomes become obvious.This set of identifiable chromosomes can be arranged into a diagram of the organism; this diagram is known as a ________.

Question 46

Parthenogenesis is a type of asexual reproduction in which embryos can be established and grow without fertilization.Essentially,this means that an embryo develops from an unfertilized egg.What is the most likely reason why the parthenogenetic whiptail lizards of the desert Southwest create no new genetic combinations during crossing-over,whereas other animals do?

A) In this species, all the crossovers are double, eventually restoring each chromosome to its
Original condition.
B) The lizards have no homologous chromosomes. In this species, crossing-over takes place between genetically identical sister chromatids; therefore, no changes occur.
C) Parthenogenetic species forgo meiosis I, the stage in which crossing-over normally occurs.
D) Accumulated mutations within this species have modified the centromeres, disrupted the formation of a bivalent, and prevented crossing-over from taking place.

Question 47

The distribution of DNA into homologous pairs of chromosomes allows

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

Question 48

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

A) Two copies of the same chromosome are able to become part of the same gamete.
B) The resulting gametes will have different gene combinations than those of their parent cells.
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.

Question 49

The spindle microtubules break down and new nuclear envelopes form during the mitotic stage called ________.

Question 50

The attachment of microtubules to the centromeres of chromosomes sets the stage for the positioning of the chromosomes at the metaphase plate; the attachment of the microtubules occurs during the mitotic phase called ________.

Question 51

How many sister chromatids are in a bivalent?

A) two
B) four
C) eight
D) 16

Question 52

Meiosis I is called a reduction division because

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

Question 53

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

Question 54

DNA molecules are exceptionally long (about 6 feet in humans)and exceptionally thin.To minimize breakage and yet facilitate transcription,DNA forms into a complex known as chromatin by wrapping around ________.

Question 55

In human females,when is meiosis II finished?

A) just before birth
B) just after birth
C) at ovulation
D) after fertilization by a sperm cell

Question 56

During anaphase I of meiosis,which of the following things happens?

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 57

Chromosomes become visible during the mitotic stage called ________.

Question 58

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

Question 59

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

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

Question 60

By the time a cell enters meiosis II,it has

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

Question 61

The sequence of events in meiosis II is prophase II,________,anaphase II,and telophase II,which is accompanied by cytokinesis.

Question 62

Unlike mitosis,during meiosis II,the nuclear membrane does not break down.

Question 63

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

Question 64

The daughter cells that are produced in meiosis I are haploid.

Question 65

The goal of ________ is to increase genetic diversity by creating a new diploid individual from haploid cells that are derived from two different individuals; the aforementioned haploid cells join together to make a zygote during a process called ________.

Question 66

The procedure that enables a young woman to freeze her eggs when she is single and save them for later use,up to age 50,is called ________.

Question 67

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

Question 68

At the end of telophase,the cell is ready for physical division into two cells; this process is called ________.

Question 69

The events in meiosis I are almost identical to the events in mitosis.

Question 70

During prophase,the opposite ends,or spindle poles,of a cell that is beginning mitosis are determined by the separation of the ________.

Question 71

New nuclei form during the anaphase stage of cell division.

Question 72

Cytokinesis and mitosis are the same processes.

Question 73

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

Question 74

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

Question 75

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

Question 76

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

Question 77

One way to create genetic diversity is through the random distribution of chromosomes into daughter cells during the meiotic stage of ________.

Question 78

The four cells that result from meiosis are not diploid like the cells produced by mitosis; instead,they are ________.

Question 79

Cytokinesis occurs during interphase.

Question 80

Microtubules attach to plaques of protein on chromosomes; these plaques are called ________.