Bio 105 Chapter 11
56. Which of the following statements about homologous chromosome pairs is false? a. They come from only one of the individual's parents. b. They usually contain slightly different versions of the same genetic information. c. They separate from each other during meiosis I. d. They synapse during meiosis I. e. All of the above are true; none is false.
a
64. The diploid number for Norway rats is 42. How many different types of gametes can be produced from meiosis in a diploid organism from independent assortment alone (i.e., no crossing over)? a. 221 b. 242 c. 284 d. 212 e. 422
a
69. Accidents that can occur during meiosis and result in trisomies and monosomies are called a. nondisjunctions. b. inversions. c. reciprocal translocations. d. recombinations. e. acrocentricities.
a
7. Which of the following statements about cell division in prokaryotes and eukaryotes is true? a. In prokaryotes, all cells divide if conditions are favorable; in eukaryotes, only a few cells divide, and they do so according to a developmental program. b. In eukaryotes, all cells divide if conditions are favorable; in prokaryotes, only a few cells divide, and they do so according to a developmental program. c. The process of segregation is more complicated in prokaryotes than in eukaryotes. d. Both a and c e. Both b and c
a
71. The fact that most monosomies and trisomies are lethal to human embryos illustrates the a. importance of the orderly distribution of genetic material during meiosis. b. exchange of genetic information during crossing over. c. advantage of sexual reproduction to the survival of a population. d. fact that each chromosome contains a single molecule of DNA. e. formation of haploid gametes as a result of meiosis.
a
78. Which of the following is an indicator of programmed cell death? a. Fragmented chromatin b. Swelling of the membrane c. Cell lysis d. Loss of transcription control e. None of the above
a
82. Knowledge of the cell cycle has led to improved means of treating cancer. The drug 5-fluorouracil, which blocks the synthesis of thymine, inhibits the cell cycle during a. G1 phase. b. G2 phase. c. S phase. d. prophase. e. metaphase.
a
84. High-energy radiation is often used to treat cancer. The radiation damages the cancerous cells, and the cell cycle checkpoint for DNA repair is overwhelmed. Radiation therefore a. causes apoptosis when cells are at the S and G2 checkpoints. b. inhibits the growth factor at the restriction point. c. blocks DNA replication. d. causes apoptosis only at the tumor site. e. kills all tumor cells without harming healthy cells.
a
53. In an organism with a haplontic life cycle, the adult multicellular organism is _______, and the time spent between fertilization and meiosis is _______ the time spent between meiosis and fertilization. a. haploid; longer than b. haploid; shorter than c. diploid; longer than d. diploid; equal to e. diploid; shorter than
b
57. During meiosis, the sister chromatids separate during a. anaphase I. b. anaphase II. c. S phase. d. telophase I. e. telophase II.
b
61. The total DNA content of each daughter cell is reduced during meiosis because a. chromosomes do not replicate during the interphase preceding meiosis I. b. chromosomes do not replicate between meiosis I and II. c. half of the chromosomes from each gamete are lost during fertilization. d. sister chromatids separate during anaphase of meiosis I. e. chromosome arms are lost during crossing over.
b
63. A species of a grass has a haploid number of 14. How many different types of gametes can be produced from meiosis in a diploid individual from independent assortment alone (i.e., no crossing over)? a. 27 b. 214 c. 228 d. 142 e. 282
b
67. The diagnosis of Down syndrome is made by examining the individual's a. spores. b. karyotype. c. chromatin. d. nucleosomes. e. kinetochores.
b
70. A potato has a diploid number of 48. If an egg of this plant has 23 chromosomes, the most likely explanation is that a. normal meiosis has occurred. b. nondisjunction occurred during meiosis I. c. normal mitosis has occurred. d. nondisjunction occurred during mitosis. e. crossing over occurred during meiosis I.
b
74. A triploid nucleus will have difficulty undergoing meiosis because a. the DNA cannot replicate. b. not all of the chromosomes can form homologous pairs. c. the sister chromatids cannot separate. d. cytokinesis cannot occur. e. a cell plate cannot form.
b
81. One-fourth of all human breast cancers have been found to have an increased amount of the oncogene a. p21. b. HER2. c. Cdk. d. Cyclin. e. RB.
b
55. In the sexual life cycle called alternation of generations, an organism spends roughly equal amounts of time in the _______ and the _______ stages. a. monosomic; trisomic b. haploid; monosomic c. haploid; diploid d. prokaryotic; eukaryotic e. haplontic; diplontic
c
60. The exchange of genetic material between chromatids on homologous chromosomes occurs during a. interphase. b. mitosis and meiosis. c. prophase I. d. anaphase I. e. anaphase II.
c
66. One difference between mitosis and meiosis I is that a. homologous chromosome pairs synapse during mitosis. b. chromosomes do not replicate in the interphase preceding meiosis. c. homologous chromosome pairs synapse during meiosis but not during mitosis. d. spindles composed of microtubules are not required during meiosis. e. sister chromatids separate during meiosis but not during mitosis.
c
73. The diploid number of a species of conifer is 64. How many chromosomes would a monosomic individual have? a. 31 b. 32 c. 63 d. 64 e. 65
c
75. To produce larger seeds, researchers cross two varieties of a grain. These researchers are attempting to cause a. aneuploidy. b. autopolyploidy. c. allopolyploidy. d. apoptosis. e. translocation.
c
77. Which of the following statements about necrosis is true? a. It requires ATP. b. It does not cause inflammation. c. It may occur when cells are damaged by toxins. d. It produces nucleosome-sized pieces of chromatin. e. It results in fragmentation of the cell.
c
9. Which of the following statements about meiosis and mitosis is true? a. DNA replication occurs only in mitosis. b. DNA replication occurs only in meiosis. c. The products of meiosis can be different from one another, while the products of mitosis are all the same (except for rare mutations). d. The products of mitosis can be different from one another, while the products of meiosis are all the same (except for rare mutations). e. Mitosis and meiosis are the same process.
c
10. A set of cells in the intestinal epithelium divides continually in order to replace dead cells. A microscopic examination of this population of cells would show that most of them a. have condensed chromatin. b. are in meiosis. c. are in mitosis. d. are in interphase. e. Both a and b
d
17. Regulation of the cell cycle is dependent on cyclins and cyclin-dependent kinases. The key that allows a cell to progress beyond the restriction point is a. the presence of cyclin. b. the absence of cyclin. c. the presence of cyclin and Cdk. d. phosphorylation of RB by Cdk. e. the presence of external signals from growth factors.
d
2. A bacterial cell gives rise to two genetically identical daughter cells by a process known as a. nondisjunction. b. mitosis. c. meiosis. d. fission. e. fertilization.
d
23. Replacing Arg in a histone with a neutral amino acid would make the histone _______ positively charged, and _______ likely to bind to DNA. a. more; more b. more; less c. less; more d. less; less e. None of the above; this replacement would have no effect because Arg is a neutral amino acid.
d
29. Chromatin condenses to form discrete, visible chromosomes a. early in G1. b. during S. c. during metaphase. d. during prophase. e. at the end of cytokinesis.
d
32. Which of the following does not occur during mitotic prometaphase? a. Disappearance of the nuclear envelope b. Initial movement of chromosomes toward the equatorial plate c. Adhesion of chromatids at the centromere d. Synapsis of homologous chromosomes e. Disappearance of the nuclei
d
36. In mitotic metaphase, a cell with eight sister chromatids has _______ centromeres. a. no b. one c. two d. four e. eight
d
39. Which of the following is not involved in the separation of paired chromatids and their movement to opposite poles? a. Sister chromatids attach to microtubules in opposite halves of the spindle. b. Separase hydrolyzes cohesion, allowing chromatid separation. c. Tubulin fibers move the chromatids away from the equatorial plate. d. Polar microtubules push the chromatids to the poles. e. ATP is hydrolyzed by cytoplasmic dynein.
d
42. In plant cells, cytokinesis is accomplished by the formation of a(n) a. aster. b. membrane furrow. c. equatorial plate. d. cell plate. e. spindle.
d
45. The major drawback of asexual reproduction, as compared to sexual reproduction, is that it a. takes a great deal of time. b. generates variation. c. requires cytokinesis. d. produces less variation among offspring. e. None of the above; there are no major drawbacks associated with asexual reproduction.
d
58. At the end of the first meiotic division, each chromosome consists of a. chiasmata. b. a homologous chromosome pair. c. four copies of each DNA molecule. d. two chromatids. e. a pair of polar microtubules.
d
6. During prokaryotic cell division, two chromosomes separate and are distributed to the daughter cells by a. attaching themselves to microtubules. b. a mitotic spindle. c. repellent forces. d. attaching themselves to separating membrane regions. e. Both a and b
d
65. The second meiotic division of meiosis a. returns the chromosome number to diploid before fertilization. b. allows for crossing over and random distribution of chromosomes. c. reduces cell size by dividing the cytoplasm in half. d. prevents chromosome copies from doubling at each fertilization. e. is a step required for fertilization to take place.
d
72. The haploid number in Drosophila melanogaster is 4. How many chromosomes would a trisomic individual have? a. 3 b. 7 c. 8 d. 9 e. 12
d
76. The process of programmed cell death is called a. necrosis. b. lysis. c. cell displacement. d. apoptosis. e. chiasmata.
d
8. Which of the following statements about mitosis is true? a. The chromosome number in the resulting cells is halved. b. DNA replication is completed in prophase. c. Crossing over occurs during prophase. d. Two genetically identical daughter cells are formed. e. It consists of two nuclear divisions.
d
83. Knowledge of the cell cycle has led to improved means of treating cancer. Taxol, which prevents the microtubules of the spindle fiber from functioning normally, prevents the cell cycle from entering a. G1. b. G2. c. S. d. prophase. e. interphase.
d
12. Which of the following phases of the cell cycle is not part of interphase? a. S b. G0 c. G1 d. G2 e. M
e
18. An environmental change that leads to the production of less than the expected amount of cyclin would tend to _______ the activity of the Cdk. This would lead to _______ phosphorylation of the target protein, which in turn would lead to _______ cells being stopped at the checkpoint. a. increase; increased; more b. increase; decreased; fewer c. increase: decreased; fewer d. decrease; increased; fewer e. decrease; decreased; more
e
20. Interleukins and erythropoietin are a. intracellular signaling molecules. b. Cdk's. c. cyclins. d. antitumor agents. e. growth factors.
e
24. The basic structure of chromatin has sometimes been referred to as beads on a string of DNA. These "beads" are called a. chromosomes. b. chromatids. c. supercoils. d. interphases. e. nucleosomes.
e
27. The products of mitosis are a. one nucleus containing twice as much DNA as the parent nucleus. b. two genetically identical cells. c. four nuclei containing half as much DNA as the parent nucleus. d. four genetically identical nuclei. e. two genetically identical nuclei.
e
30. Microtubules that form the mitotic spindle tend to originate from or terminate in a. centromeres and telomeres. b. euchromatin. c. centrioles and telomeres. d. the nuclear envelope. e. centrioles and kinetochores.
e
35. At the milestone that defines metaphase, the chromosomes a. separate. b. come together. c. are at opposite poles. d. cross over. e. line up at the equatorial plate.
e
40. At the milestone that defines telophase, the chromosomes a. separate. b. come together. c. cross over. d. line up. e. are at opposite poles.
e
43. The event in the cell division process that clearly involves microfilaments is a. chromosome separation during anaphase. b. movement of chromosomes to the metaphase plate. c. chromosome condensation during prophase. d. disappearance of the nuclear envelope during prophase. e. cytokinesis in animal cells.
e
5. During bacterial cell division, a single cell is separated into two cells by a. centrosomes. b. spindle fibers. c. nucleosomes. d. aneuploidy. e. pinching of the plasma membrane.
e
59. Which of the following statements about sister chromatids is false? a. They arise by replication during S phase. b. They separate from each other during each mitotic anaphase. c. They usually contain identical versions of the same genetic information. d. They are joined during prophase I and metaphase I at their common centromere. e. They separate from each other during meiosis I.
e
62. The four haploid nuclei found at the end of meiosis differ from one another in their exact genetic composition. Some of this difference is the result of a. cytokinesis. b. replication of DNA during the S phase. c. separation of sister chromatids at anaphase II. d. spindle formation. e. crossing over during prophase I.
e
68. Mitotic prophase differs from prophase I of meiosis in that a. chromatin becomes supercoiled only in mitotic prophase. b. the nuclear envelope disappears only in prophase I of meiosis. c. synapsis occurs only in mitotic prophase. d. the chromatids separate in mitotic prophase, not in prophase I of meiosis. e. crossing over is characteristic of prophase I of meiosis but not of mitotic prophase.
e
79. Caspases play a role in the process of a. autopolyploidy. b. allopolyploidy. c. aneuploidy. d. necrosis. e. apoptosis.
e
80. Which of the following statements about benign tumors is true? a. Their cells do not resemble the cells of the parent tissue. b. Their cells are often irregular, with nuclei of various sizes and shapes. c. Their cells grow more rapidly than the surrounding cells. d. They often metastasize. e. They are not cancerous.
e
52. Each diploid cell of a human female contains _______ of each type of chromosome. a. 1 b. 2 c. 4 d. 23 e. 46
b
34. The microtubules of the mitotic spindle attach to a specialized structure in the centromere region of each chromosome called the a. kinetochore. b. nucleosome. c. equatorial plate. d. aster. e. centrosome.
a
41. Chromosomes "decondense" into diffuse chromatin a. at the end of telophase. b. at the beginning of prophase. c. at the end of interphase. d. at the end of metaphase. e. only in dying cells.
a
44. The distribution of mitochondria between the daughter cells during cytokinesis a. is random. b. is directed by the mitotic spindle. c. is directed by the centrioles. d. results in the mitochondria remaining in the parent cell. e. occurs only during meiosis.
a
11. Mature nerve cells, which are incapable of cell division, are most likely in a. G1. b. the S phase. c. G2. d. mitosis. e. meiosis.
a
13. How does a nucleus in G2 differ from a nucleus in G1? a. The G2 nucleus has double the amount of DNA as the G1 nucleus. b. DNA synthesis occurs only in G1 phase. c. Inactive cells are arrested only in G2 phase. d. During G2, the cell prepares for S phase. e. None of the above; there is no difference in the nucleus between G1 and G2.
a
15. A tissue in a mouse contains two types of cells: one that divides rapidly and one that divides more slowly. The most likely difference between these two cell types is that the slow-dividing cell type spends more time in _______ phase. a. G1 b. G2 c. G3 d. M e. S
a
21. The DNA of a eukaryotic cell is a. double-stranded and linear. b. single-stranded and linear. c. double-stranded and circular. d. single-stranded and circular. e. conservative.
a
26. During mitosis and meiosis the chromatin compacts. Which of the following processes takes place more easily because of this compaction? a. The orderly distribution of genetic material to two new nuclei b. DNA replication c. Exposing of the genetic information on the DNA d. The unwinding of DNA from the histones e. The disappearance of the nuclear membrane
a
31. At the milestone that defines anaphase, the chromosomes a. separate. b. come together. c. are at opposite poles. d. line up. e. cross over.
a
14. If a cell in G2 has 1.6 picograms (pg) of DNA, it had _______ of DNA in G1. a. 0.4 pg b. 0.8 pg c. 1.6 pg d. 3.2 pg e. 1.6 pg if it is a plant cell and 3.2 pg if it is an animal cell
b
19. Which of the following would be the most likely result of a mutation in a eukaryotic organism that causes it to produce less p21 protein than normal? a. Cell replication would be slowed if the organism receives radiation. b. Cells with radiation-induced DNA damage would continue through the cell cycle without repairing the damaged DNA. c. Cells with incomplete DNA replication would continue through the checkpoint. d. Cells would not respond to growth factors. e. Cells would have a hyper-sensitive response to growth factors.
b
25. Chromatin consists of a. DNA and histones. b. DNA, histones, and many other proteins. c. RNA and DNA. d. RNA, DNA, and non-histone proteins. e. DNA only.
b
28. Centrosomes a. are constricted regions of phase chromosomes. b. determine the plane of cell division. c. are the central region of the cell. d. are the region where the membrane constricts during cytokinesis. e. are part of cilia.
b
33. The structures that line up the chromatids on the equatorial plate during metaphase are called a. asters. b. polar and kinetochore microtubules. c. centrosomes. d. centrioles. e. histones.
b
4. Which of the following would most likely result from a mutation in the ori gene of a bacterial cell? a. The cell would not be able to detect whether conditions were favorable for replication. b. The initiation of DNA replication would be hindered. c. DNA replication would be prolonged abnormally. d. The cell would not be able to segregate DNA molecules. e. The cell could not undergo meiosis.
b
47. A haploid cell is a cell a. in which the genes are arranged haphazardly. b. containing only one copy of each chromosome. c. that has resulted from the process of mitosis. d. with twice the number of chromosomes of a diploid cell. e. None of the above
b
49. Most zygotes are a. multicellular. b. diploid. c. animals. d. clones. e. gametes.
b
1. Which of the following is not one of the events required for cell division? a. Segregation b. Cytokinesis c. Crossing over d. DNA replication e. All of the above are required for cell division.
c
16. Cyclin-dependent kinases (Cdk's) catalyze the phosphorylation of targeted proteins, a process that a. decreases the mass of the protein. b. makes the targeted proteins hydrophobic. c. changes the shape and function of the targeted proteins. d. gives the proteins a three-dimensional shape. e. blocks the cell cycle from proceeding.
c
22. Chromosomes contain large amounts of interacting proteins known as a. pentanes. b. hexosamines. c. histones. d. protein hormones. e. cyclins.
c
3. If a bacterial colony is grown in a medium rich in the amino acid lysine, cell division proceeds rapidly and the colony grows steadily. If the lysine concentration drops, cell division slows; if the lysine concentration is restored, cell division resumes. Lysine is thus a(n) a. fertilization signal. b. ori site. c. reproductive signal. d. oncogene. e. fission activator.
c
37. Late in mitotic anaphase, a cell with 28 daughter chromosomes has _______ centromeres in the dividing cell. a. no b. 14 c. 28 d. 56 e. None of the above
c
38. The energy to move chromosomes during mitosis is provided by a. centrioles. b. DNA polymerization. c. ATP d. formation of the cell plate. e. None of the above; energy is not required for this action.
c
46. During asexual reproduction, the genetic material of the parent is passed on to the offspring by a. homologous pairing. b. meiosis and fertilization. c. mitosis and cytokinesis. d. karyotyping. e. chiasmata.
c
48. A mechanism for increasing the genetic diversity of offspring is a. mitosis. b. cloning. c. sexual reproduction. d. cytokinesis. e. fission.
c
50. In a particular diploid organism, somatic cells have 24 chromosomes. How many chromosomes would be present in the gametes of that organism? a. 1 b. 6 c. 12 d. 24 e. 48
c
51. Asexual reproduction produces genetically identical individuals because a. chromosomes do not have to replicate during asexual reproduction. b. it involves chromosome replication without cytokinesis. c. no meiosis or fertilization take place. d. cell division occurs only in meiosis. e. the mitotic spindle prevents nondisjunction.
c
54. Organisms that are haplontic differ from those that are diplontic in a. whether their cell cycles contain checkpoints. b. the number of chromosomes they contain. c. the extent to which they develop in the diploid state during their life cycle. d. whether they undergo meiosis. e. None of the above
c