Deck 8: DNA Replication, mitosis, and the Cell Cycle

Question 1

The enzyme that adds nucleotides along the 5' to 3' along a DNA strand,is

A) primase.
B) DNA polymerase.
C) helicase.
D) ligase.
E) ATP synthase.

Answer 1

B

Question 2

The molecule that contains the information for making a cell's proteins and copies itself for the next generation of cells is

A) DNA.
B) ATP synthase.
C) RNA.
D) NAD.
E) FAD.

Answer 2

A

Question 3

The process by which DNA is reproduced,with the use of associated enzymes,is

A) translation.
B) catalyzed protein synthesis.
C) transcription.
D) ligation.
E) replication.

Answer 3

E

Question 4

The building block of nucleic acids is a(n)

A) glucose molecule.
B) None of the answer choices are correct.
C) nucleotide.
D) glycerol molecule.
E) amino acid.

Question 5

Figuer:
This diagram shows how DNA is packaged and folded with its associated protective and regulatory proteins.
A discrete continuous molecule of DNA,wrapped with its associated proteins,defines the term

A) histone.
B) genome.
C) nucleosome.
D) centromere.
E) chromosome.

Question 6

A human heart cell contains ___ chromatids.

A) 4
B) 46
C) 23
D) 2
E) 16

Question 7

Before any cell divides into two daughter cells,it must first duplicate its

A) entire genome.
B) cell membrane structure.
C) All of the answer choices are correct.
D) cytoplasmic contents.
E) array of enzymes.

Question 8

The enzyme that joins Okazaki fragments is

A) primase.
B) DNA polymerase.
C) helicase.
D) ATP synthase.
E) ligase.

Question 9

Apoptosis is a name for the process of

A) mitosis.
B) programmed cellular reproduction.
C) replication.
D) programmed cell death.
E) the cell cycle.

Question 10

The enzyme that builds a short complementary piece of RNA at the start of each DNA segment to be replicated is

A) helicase.
B) ligase.
C) DNA polymerase.
D) primase.
E) ATP synthase.

Question 11

The genome of an organism is all of its

A) genetic material.
B) RNA.
C) characteristics.
D) All of the answer choices are correct.
E) proteins.

Question 12

The four nitrogen bases that are found in the different nucleotides of DNA are

A) adenine, thymine, cytosine, guanine.
B) uracil, adenine, cytosine, guanine.
C) None of the answer choices are correct.
D) adenine, thymine, cytosine, uracil.
E) uracil, cytosine, guanine, thymine.

Question 13

DNA replication is

A) a one-step process.
B) not carried out in prokaryotic cells.
C) not carried out by enzymes.
D) conservative.
E) semi-conservative.

Question 14

Strong evidence of semiconservative replication of DNA comes from the DNA molecule structure,in that

A) the DNA molecule has four distinct nitrogen base pairs, requiring minimal chemical bond reactions to replicate their sequence.
B) All these properties of DNA and the replication process are part of the evidence and definition of semiconservative replication.
C) the semiconservative replication is explained by the large number of enzymes that are each specialized for each step of replication.
D) the DNA molecule is double-stranded, allowing one original strand to be conserved while its replicate forms one strand.
E) the hydrogen bonds between paired DNA strands allows conservation of energy, at a lower level than covalent bonds would require.

Question 15

The complement strands of DNA have the same exact nitrogen base sequence,providing the semiconservative replication needed by cells.

Question 16

Complementary DNA strands are held together by

A) ionic bonds.
B) hydrogen bonds.
C) covalent bonds.
D) phosphodiester bonds.

Question 17

Among enzymes required for DNA replication,ligases are needed to form ____ bonds between to join nucleotides to DNA segments.

A) covalent
B) weak chemical
C) ionic
D) hydrogen

Question 18

Mutations are usually rare,because

A) Okazaki fragments are removed, whenever detected by the ligase enzyme.
B) transcription, after replication, will normally detect and fix mutations.
C) ligases serve to conduct "quality control" checks in order to repair mutations.
D) DNA polymerase quickly discards mismatched nucleotide base pairs.
E) Both answer options, regarding the role of the ligase enzyme, are correct.

Question 19

The enzyme that unwinds and separates the paired DNA strands is

A) ATP synthase.
B) ligase.
C) DNA polymerase.
D) primase.
E) helicase.

Question 20

The component of the DNA nucleotides that varies to produce an organism's genetic information is the deoxyribose.

Question 21

The phase of mitosis in which the nuclear envelope breaks into small pieces is

A) C, which is metaphase.
B) B, which is prometaphase.
C) D, which is anaphase.
D) C, which is telophase.
E) B, which is prophase.

Question 22

The correct sequence for the phases of the cell cycle,starting with a newly divided cell,is

A) cytokinesis - replication - interphase - mitosis.
B) interphase - mitosis - cytokinesis.
C) interphase - binary fission - cytokinesis.
D) replication - binary fission - cytokinesis.
E) cytokinesis - mitosis - interphase.

Question 23

The portion of the cytoskeleton that attaches,pulls,and guides the chromosomes as they are separated equally into two sets is the

A) centrosome.
B) Golgi body.
C) centromere.
D) mitotic spindle.
E) kinetochore.

Question 24

In a biology lab exercise,you are asked to examine cells of a growing onion root tip,that has been sectioned to show many cells.In most of the cells,you easily see the circular or oval nucleus as a uniformly filled space in a membrane outline.In a small percentage of cells,you see chromosomes as distinct strands just as cell division begins,and as it progresses,because the chromatin

A) becomes more tightly folded, increasing their visible length.
B) becomes less tightly folded, increasing their visible length.
C) becomes less tightly wound, to facilitate cell division.
D) becomes more tightly wound, to protect DNA, and to more easily manage cell division.
E) increases in length, as replication adds DNA sections to the original.

Question 25

The correct sequence for the phases of mitosis,shown in correct sequence in this diagram,is

A) interphase - metaphase - anaphase - prophase - telophase.
B) prophase - prometaphase - metaphase - anaphase - telophase.
C) prometaphase - prophase - metaphase - anaphase - telophase.
D) interphase - prophase - metaphase - anaphase - telophase.
E) prophase - metaphase - prometaphase - anaphase - telophase.

Question 26

A part of a chromosome,that attaches sister chromatids to each other,defines the term

A) nucleosome.
B) None of the answer choices are correct.
C) chromatin.
D) histone.
E) centromere.

Question 27

DNA is packaged to protect and manage the genetic information of the cell.What is the correct comparison between the packaging units of DNA?

A) While chromatin is the collective term for the substance of DNA and associated proteins, chromosomes are the distinct units that are compact and visible during cell division.
B) While chromosome is the collective term for the substance of DNA and associated proteins, chromatin is the fluid and other molecules in the nucleus, that regulate cell division.
C) While the nucleus contains chromatin substance in general, the nucleosome is a secondary compartment that forms prior to cell division, as a location where chromosomes will replicate and divide.
D) Chromosomes are the distinct folded units containing the DNA molecule, while chromatin in the nucleosome is the location of the associated proteins.
E) The histones are protective proteins in chromatids, but the nucleosomes and centromeres are part of the actively dividing chromosomes.

Question 28

While in the biology lab,you observe,in both plant and animal cells,that some single cells are splitting into two daughter cells,in the process of

A) metaphase.
B) mitosis.
C) cytokinesis.
D) binary fission.
E) anaphase.

Question 29

The process by which a sperm cell combines with an egg cell is

A) replication.
B) germination.
C) mitosis.
D) fertilization.
E) recombination.

Question 30

An embryo fish is in its egg,without fully developed tissues and organs to survive outside the egg.The embryo has a large number of cells undergoing mitosis for the purpose of

A) production of new cells that can differentiate and specialize for different functions.
B) replication of new DNA copies, so that meiosis will further grow the embryo.
C) sexual reproduction of gametes, to produce new offspring.
D) asexual reproduction, to produce larger numbers of embryos, so that some will survive.
E) fertilization of the gametes, so the embryo can continue growing and hatch.

Question 31

Figuer:
This diagram shows the steps in mitosis, with labels to reference in the questions below.
In which of these mitosis phases is the replication of DNA accomplished?

A) None of these answer options are correct, because replication does not happen during mitosis.
B) A, which is mitosis.
C) C, which is telophase.
D) A, which is prophase.
E) E, which is cytokinesis.

Question 32

A person,who has just experienced a painful sunburn,has a large number of cells undergoing mitosis for the purpose of

A) replication of new DNA copies, so that meiosis will further grow new skin cells.
B) modifying new cells that will have different specialties than the original damaged cells.
C) asexual reproduction, to produce new skin buds that will fold over and cover the burn.
D) repairing and replacing the damaged cells, in the healing process of the skin.

Question 33

The phase of mitosis in which the centromeres split and sister chromatids are pulled to opposite poles of the cell is

A) E, which is metaphase.
B) B, which is prophase.
C) D, which is anaphase.
D) A, which is prometaphase.
E) E, which is telophase.

Question 34

Sister chromatids are

A) genetically identical and attached to each other at the centromere.
B) genetically different and attached to each other at the centromere.
C) genetically identical.
D) genetically different.
E) attached to each other at the centromere.

Question 35

After replication,in eukaryotes,both the original and its replicated copy chromosome are each called a

A) chromosome.
B) centromere.
C) chromatin.
D) sister chromatid.
E) nucleosome.

Question 36

The eukaryotic cell will complete the ___ portion of the cell cycle in order to___

A) interphase; build the mitotic spindle and metaphase plate between original and replicate chromosome groups.
B) cytokinesis; move the centrioles, centrosomes, and mitotic spindle into position to pull chromosomes apart.
C) mitosis; divide the original and replicated chromosomes.
D) synthesis; build the two new daughter cells from the original one cell.
E) binary fission; divide the original and replicated chromosomes.

Question 37

The two main stages of the eukaryote cell cycle,in which the cell spends most of its time and metabolic energy,are

A) interphase and cytokinesis.
B) interphase and binary fission.
C) mitosis and meiosis.
D) interphase and mitosis.
E) mitosis and cytokinesis.

Question 38

Meiosis is a process used for

A) growth of an organism.
B) repair of damaged cells.
C) production of gametes.
D) asexual reproduction.
E) production of stem cells.

Question 39

A seedling plant has a section of the stem tip that contains large numbers of cells undergoing mitosis for the purpose of

A) sexual reproduction of gametes, to produce new offspring.
B) growth in height of the plant.
C) replication of the DNA in the stem, where new flowers will go through meiosis.
D) asexual reproduction of gametes, to produce new offspring.
E) fertilization of the gametes in order to produce new offspring.

Question 40

A nucleosome consists of

A) two or more closely related genes.
B) a ribosome and RNA.
C) a stretch of DNA.
D) a stretch of DNA and histones.
E) an RNA molecule.

Question 41

The phase of mitosis in which the chromosomes are aligned along the equator of the cell is

A) A, which is prophase.
B) A, which is prometaphase.
C) D, which is anaphase.
D) E, which is telophase.
E) C, which is metaphase.

Question 42

If scientists could inactivate telomerase in specific cells,the primary reason for this would most likely be the stopping of

A) the formation of cancer.
B) meiosis.
C) aging of cells.
D) All of the answer choices are correct.
E) aerobic respiration.

Question 43

The proteins to which the mitotic spindle attaches on a chromosome are

A) kinetochores.
B) chromatids.
C) nucleosomes.
D) centromeres.
E) histones.

Question 44

The chemotherapy drug taxol inhibits the breakdown of microtubules.A cell treated with taxol would become stuck right after which phase?

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

Question 45

If scientists could increase telomerase production in specific cells,the primary reason for this would most likely be the stopping of

A) aging of cells.
B) cancer cell formation.
C) aerobic respiration.
D) meiosis.
E) All of the answer choices are correct.

Question 46

Why does a replication fork have a leading and lagging strand?

A) because DNA synthesis always goes from 5' to 3'
B) because DNA polymerase only attaches nucleotides to the 3' end of strands
C) because DNA synthesis can grow off of either the 3' or 5' end
D) because DNA synthesis always goes from 3' to 5'
E) Both answers, with DNA synthesis proceeding from 5' to 3', and DNA polymerase only acting on the 3' end, are correct.

Question 47

In an asexual life cycle,cells reproduce by

A) meiosis and fertilization.
B) meiosis.
C) All of the answer choices are correct.
D) fertilization.
E) mitosis.

Question 48

The structure that organizes the protein subunits of the mitotic spindle is the

A) centrosome.
B) centromere.
C) microfilaments.
D) kinetochore.
E) cytoskeleton.

Question 49

Why don't plant cells form a cleavage furrow during cytokinesis?

A) because their cells don't divide after mitosis, but become one larger cell with multiple nuclei
B) because they don't have a cell membrane
C) because they have a cell wall
D) because they don't have a nucleus
E) All of the answer choices are correct.

Question 50

In a sexual life cycle,a zygote grows to an adult by

A) fertilization.
B) mitosis.
C) meiosis.
D) meiosis and fertilization.
E) All of the answer choices are correct.

Question 51

When DNA replicates

A) transcription factors determine where to begin DNA replication.
B) the original DNA unwinds, and multiple copies of a region are transcribed before the DNA closes back up.
C) the original DNA is not affected and a new double-stranded DNA is made from two new strands of DNA.
D) None of the answer choices are correct.
E) one strand of the original DNA ends up in each of the new DNA molecules.

Question 52

In the biology lab,you observe animal cells that resemble this first sign of cytokinesis,the formation of this

A) cell plate.
B) nuclear envelope.
C) cell wall.
D) nucleolus.
E) cleavage furrow.

Question 53

The phase of mitosis in which the chromosomes condense and centrosomes move to opposite poles of the cell is

A) B, which is prometaphase.
B) C, which is metaphase.
C) D, which is anaphase.
D) E, which is telophase.
E) A, which is prophase.

Question 54

If a mutation causes the "T" base in the base sequence 5'-AGTCCG-3' to be read as a "G" base,DNA replication of the mutated sequence will read:

A) 3'-CTTAAT-5'
B) 3'-AGGCCG-5'
C) 3'-UCCGGC-5'
D) 3'-TCCGGC-5'
E) 3'-AGTCCG-5'

Question 55

In the biology lab,you observe three different animal cells under a microscope.In one cell,the nucleus is uniformly filled,with no distinct chromosome structure visible.In another,you see the nucleus with two nucleolus areas of more compact chromatin.A third cell is in mitosis,and distinct chromosome strands are visible.The value in packaging DNA in tighter forms of chromatin is for

A) regulation and protection of the DNA during transcription.
B) Both answers regarding DNA mobility, protection and regulation in mitosis and transcription are correct.
C) prevention of ligase enzyme action during replication.
D) mobility and protection of the DNA molecule during mitosis.
E) insuring that sister chromatids will be attached prior to replication.

Question 56

If one strand of a DNA molecule has the base sequence of 5'-ATGTGCC-3' the complementary strand of DNA will read

A) 3'-UACACGG-5'
B) 3'-GGCACAT-5'
C) 3'-CGTGTAA-5'
D) 3'-ATGTGCC-5'
E) 3'-TACACGG-5'

Question 57

The phase of mitosis in which the nuclear envelope reforms is

A) E, which is telophase.
B) C, which is anaphase.
C) A, which is prometaphase.
D) D, which is metaphase.
E) B, which is prophase.

Question 58

By ignoring a checkpoint in the cell cycle,a cancer cell may

A) pull chromosomes apart during anaphase.
B) divide before its DNA is completely replicated.
C) align chromosomes on the equator of the cell during metaphase.
D) divide after mutations are fixed.
E) condense its chromosomes before mitosis.

Question 59

How does the space between our fingers arise?

A) The cells die by necrosis.
B) Mitosis of the cells is blocked.
C) The cells die by apoptosis.
D) The cells become part of the fingers.
E) Meiosis of the cells is blocked.

Question 60

In biology lab,as you are examining plant root cells,you are having difficulty determining what you are seeing as in the image below.You can still see chromosome strands,as they are in compact bundles.You think this should be telophase,because the chromosomes aren't being actively pulled apart,but when does cytokinesis start? The first sign that cytokinesis has started is the formation of a

A) nucleolus.
B) nuclear envelope.
C) spindle fiber.
D) cell plate.
E) cleavage furrow.

Question 61

Any change in a cell's DNA sequence is a mutation.

Question 62

In order for a cell to become cancerous,oncogenes must be ___,or tumor suppressors are ___.

A) activated; activated
B) activated; inactivated
C) inactivated; inactivated
D) inactivated; activated

Question 63

When studying endostatin,why did Boehm et al.induce cancer in mice by injecting cancer cells,instead of just doing the experiment on isolated cancer cells in culture?

A) Oncogenes are only active in whole tumors.
B) Tumor suppressors are only active in whole tumors.
C) Cancer cells can go through angiogenesis in culture.
D) Cancer cells cannot be grown outside of the body in culture.
E) Angiogenesis involves multiple tissues in a whole organism.

Question 64

The enzyme telomerase adds DNA to the ends of chromosomes.Why would cancer cells express high levels of telomerase?

A) Longer chromosomes have more active genes.
B) Telomerase is a tumor suppressor.
C) As telomeres get shorter, a cell loses the ability to divide.
D) The longer a chromosome is, the more genes a cancer cell will have.
E) It allows the chromosomes to be replicated more rapidly.

Question 65

Figuer:
What did the researchers conclude based on the data in figure (a)?

A) Cyclophosphamide delayed the growth of tumors but resistance developed.
B) Endostatin shrunk tumors without development of resistance.
C) Endostatin shrunk tumors but resistance developed.
D) Tumors in untreated cells shrank in size.
E) Cyclophosphamide delayed the growth of tumors without development of resistance.

Question 66

If a cancer metastasizes,its cells travel through the bloodstream or the lymphatic system and colonize other areas of the body.

Question 67

Cyclophosphamide forms cross links between the two strands of DNA in a chromosome.How would this be effective in chemotherapy?

A) It would block splicing.
B) It would activate oncogenes.
C) It would block metaphase.
D) It would inactivate tumor suppressors.
E) It would block DNA replication.

Question 68

What hypothesis did Boehm,et al.develop after testing mice (initially)and eventually humans?

A) Because endostatin works on endothelial cells, natural selection for resistance may arise in tumor cells not initially killed.
B) Because endostatin works on tumor cells, natural selection for resistance will not occur in endothelial cells.
C) Because cyclophosphamide works on endothelial cells, natural selection for resistance will not occur in tumor cells.
D) Because cyclophosphamide works on tumor cells, natural selection for resistance will not occur in endothelial cells.

Question 69

Figuer:
What is the dependent variable in this figure?

A) treatment with cyclophosphamide
B) treatment days
C) treatment with endostatin
D) the volume of the tumor

Question 70

Replication takes place during the G₁ phase of interphase.

Question 71

Endostatin is a 184-amino acid protein that only affects endothelial cells.What is the best explanation for this observation?

A) Endostatin enters endothelial cells by endocytosis.
B) Endostatin can diffuse across the membrane of endothelial cells.
C) Endothelial cells have a receptor on their cell membrane that binds endostatin.
D) Only endothelial cells are exposed to endostatin.
E) Endothelial cells produce endostatin.

Question 72

In the biology lab,you are shown petri dishes of cheek cell cultures.One set of cells is thin,with individual cells arranged in a single,orderly layer.The other culture shows irregular crowding of cells.The crowding cells are likely cancer cells,showing an absence of

A) oncogenes.
B) contact inhibition.
C) All of these answers are visually characteristic of cancer cells.
D) angiogenesis.
E) telomerases.

Question 73

Cells that produce telomerase can usually divide many more times than cells that do not produce telomerase.

Question 74

A replicated chromosome consists of two sister chromatids.

Question 75

Change in a cell's DNA sequence is a common occurrence in the process of replication.

Question 76

Each newly replicated molecule of DNA contains one conserved strand from the original DNA molecule.

Question 77

Figuer:
What did the researchers conclude based on the data in figure (b)?

A) Endostatin shrunk tumors without development of resistance.
B) Cyclophosphamide slowed the growth of tumors but resistance developed.
C) Cyclophosphamide slowed the growth of tumors without development of resistance.
D) Tumors in untreated cells shrank in size.
E) Endostatin shrunk tumors but resistance developed.

Question 78

Why would a cancer cell need to induce angiogenesis?

A) It would activate oncogenes.
B) Cells in the center of a tumor would benefit from a larger blood supply.
C) Cells could then produce proteins that avoid checkpoints in the cell cycle.
D) It is another name for stage I in metastasis.
E) It would inactivate tumor suppressors.

Question 79

During the cell cycle there are several checkpoints that ensure that the cell cycle is proceeding correctly.

Question 80

An abnormal mass of tissue is a tumor.