Campbell Biology Ch.12 &13
How is plant cell cytokinesis different from animal cell cytokinesis? - The structural proteins of plant cells separate the two cells; in animal cells, a cell membrane separates the two daughter cells. - Plant cells deposit vesicles containing cell wall building blocks on the metaphase plate; animal cells form a cleavage furrow. - Plant cells divide after metaphase but before anaphase; animal cells divide after anaphase. - The contractile filaments found in plant cells are structures composed of carbohydrates; the cleavage furrow in animal cells is composed of contractile proteins.
- Plant cells deposit vesicles containing cell wall building blocks on the metaphase plate; animal cells form a cleavage furrow.
13) Which of the following processes might produce a human zygote with 45 chromosomes? A) an error in meiotic anaphase occurring in either an egg or sperm B) failure of the egg nucleus to be fertilized by the sperm C) failure of an egg to complete meiosis II D) incomplete cytokinesis during spermatogenesis after meiosis I
A
18) In a life cycle such as that shown in part III of the figure above, if the zygote's chromosome number is ten, which of the following statements will be true? A) The sporophyte's chromosome number per cell is ten and the gametophyte's is five. B) The sporophyte's chromosome number per cell is five and the gametophyte's is ten. C) The sporophyte and gametophyte each have ten chromosomes per cell. D) The sporophyte and gametophyte each have five chromosomes per cell.
A
23) If a cell has completed meiosis I and the first cytokinesis, and is just beginning meiosis II, which of the following is an appropriate description of its genetic contents? A) It has half the amount of DNA as the cell that began meiosis. B) It has half the chromosomes but twice the DNA of the parent cell. C) It has one-fourth the DNA and one-half the chromosomes as the parent cell. D) It is genetically identical to another cell formed from the same meiosis I event.
A
27) Which of the following events happens at the conclusion of meiosis I? A) Homologous chromosomes of a pair are separated from each other. B) The chromosome number per cell remains the same. C) Sister chromatids are separated. D) Four daughter cells are formed.
A
37) Which sample of DNA might represent a zygote? A) I B) II C) III D) either I or II
A
45) Which of the following statements describes a major difference between mitosis and meiosis I in a diploid organism? A) Sister chromatids separate in mitosis, while homologous pairs of chromosomes separate in meiosis I. B) Sister chromatids separate in mitosis, while homologous pairs of chromosomes separate in meiosis II. C) DNA replication takes place prior to mitosis, but not before meiosis I. D) Only meiosis I results in daughter cells that contain identical genetic information.
A
50) During which of the following processes does independent assortment of chromosomes occur? A) in meiosis I only B) in meiosis II only C) in mitosis and meiosis I D) in mitosis and meiosis II
A
52) Independent assortment of chromosomes is a result of which of the following processes? A) the random way each pair of homologous chromosomes lines up at the metaphase plate during meiosis I B) the random combinations of eggs and sperm during fertilization C) the random distribution of the sister chromatids to the two daughter cells during anaphase II D) the diverse combination of alleles that may be found within any given chromosome
A
54) How does natural selection apply to sexual reproduction as opposed to asexual reproduction? A) Sexual reproduction results in many new gene combinations, some of which will lead to differential reproduction. B) Sexual reproduction results in the greatest number of new mutations. C) Sexual reproduction allows the greatest number of offspring to be produced. D) Sexual reproduction utilizes far less energy than asexual reproduction.
A
57) Imagine that there are 25 different species of protists living in a tide pool. Some of these species reproduce both sexually and asexually, and some of them can reproduce only asexually. The pool gradually becomes infested with disease-causing viruses and bacteria. Which species are more likely to thrive in the changing environment? A) The sexually reproducing species is likely to thrive. B) The asexually reproducing species is likely to thrive. C) Sexually and asexually reproducing species are equally likely to thrive. D) Neither species will be able to thrive.
A
DNA was isolated from three different cell types of the same organism, the relative DNA content for each type was determined, and the results were plotted on the graph shown in the figure below. Refer to the graph to answer the following questions. 35) Which sample of DNA might be from a cell that stopped the process of cell division in G0 phase of the cell cycle prior to meiosis? A) I B) II C) III D) either I or II
A
Refer to the drawings in the figure below of a single pair of homologous chromosomes as they might appear during various stages of either mitosis or meiosis, and answer the following question(s). 33) Which diagram represents anaphase I of meiosis? A) I B) II C) IV D) V
A
Refer to the life cycles illustrated in the figure below to answer the following questions. 15) Which of the life cycles is typical for animals? A) I only B) II only C) III only D) I and III
A
3) If there are 20 chromatids in a cell, how many centromeres are there? A) 10 B) 20 C) 30 D) 40 E) 80
A) 10
8. If there are 20 centromeres in a cell at anaphase, how many chromosomes are there in each daughter cell following cytokinesis? A) 10 B) 20 C) 30 D) 40 E) 80
A) 10
78. 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) G₁. B) G₂. C) prophase. D) metaphase. E) anaphase.
A) G₁.
29. Which of the following is released by platelets in the vicinity of an injury? A) PDGF B) MPF C) protein kinase D) cyclin E) Cdk
A) PDGF
47. At the M phase checkpoint, the complex allows for what to occur? A) Separase enzyme cleaves cohesins and allows chromatids to separate. B) Cohesins alter separase to allow chromatids to separate. C) Kinetochores are able to bind to spindle microtubules. D) All microtubules are made to bind to kinetochores. E) Daughter cells are allowed to pass into G₁.
A) Separase enzyme cleaves cohesins and allows chromatids to separate.
70. A student is looking through his light microscope (~450 X) at a squashed and stained onion root tip. Some, but not all, of the cells have clearly visible chromosome strands. 70) When a cell is in anaphase of mitosis, which of the following will he see? A) a clear area in the center of the cell B) chromosomes clustered at the poles C) individual chromatids separating D) chromosomes clustered tightly at the center E) formation of vesicles at the midline
A) a clear area in the center of the cell
35. The MPF protein complex turns itself off by A) activating a process that destroys cyclin components. B) activating an enzyme that stimulates cyclin. C) binding to chromatin. D) exiting the cell. E) activating the anaphase-promoting complex.
A) activating a process that destroys cyclin components.
76. In the cells of some organisms, mitosis occurs without cytokinesis. This will result in A) cells with more than one nucleus. B) cells that are unusually small. C) cells lacking nuclei. D) destruction of chromosomes. E) cell cycles lacking an S phase.
A) cells with more than one nucleus.
The centromere is a region in which: A) chromatids remain attached to one another until anaphase. B) metaphase chromosomes become aligned at the metaphase plate. C) chromosomes are grouped during telophase. D) the nucleus is located prior to mitosis. E) new spindle microtubules form at either end.
A) chromatids remain attached to one another until anaphase.
73. Vinblastine is a standard chemotherapeutic drug used to treat cancer. Because it interferes with the assembly of microtubules, its effectiveness must be related to A) disruption of mitotic spindle formation. B) inhibition of regulatory protein phosphorylation. C) suppression of cyclin production. D) myosin denaturation and inhibition of cleavage furrow formation. E) inhibition of DNA synthesis.
A) disruption of mitotic spindle formation.
61. Of the following, the best conclusion concerning the difference between the S phases for beta and gamma is that A) gamma contains more DNA than beta. B) beta and gamma contain the same amount of DNA. C) beta cells reproduce asexually. D) gamma contains 48 times more DNA and RNA than beta. E) beta is a plant cell and gamma is an animal cell.
A) gamma contains more DNA than beta.
21. Which of the following was a discovery that had to be made before human chromosomes could be correctly counted? A) how to use a hypotonic solution to swell nuclei B) how to visualize sperm nuclei C) how to visualize chromosomes D) when to see chromosomes separate from one another E) when to see chromosomes in pairs
A) how to use a hypotonic solution to swell nuclei
26. You have the technology necessary to measure each of the following in a sample of animal cells: chlorophylls, organelle density, picograms of DNA, cell wall components, and enzymatic activity. Which would you expect to increase significantly from M to G₁? A) organelle density and enzymatic activity B) cell wall components and DNA C) chlorophyll and cell walls D) organelle density and cell walls E) chlorophyll and DNA
A) organelle density and enzymatic activity
20. During which phase of mitosis do the chromatids become chromosomes? A) telophase B) anaphase C) prophase D) metaphase E) cytokinesis
A) telophase
10. Taxol is an anticancer drug extracted from the Pacific yew tree. In animal cells, Taxol disrupts microtubule formation by binding to microtubules and accelerating their assembly from the protein precursor, tubulin. Surprisingly, this stops mitosis. Specifically, Taxol must affect A) the formation of the mitotic spindle. B) anaphase. C) formation of the centrioles. D) chromatid assembly. E) the S phase of the cell cycle.
A) the formation of the mitotic spindle.
Density-dependent inhibition is explained by which of the following processes?
As cells become more numerous, the cell surface proteins of one cell contact the adjoining cells and they stop dividing.
10) Which of the following statements describes an example of alternation of generations? A) A grandparent and grandchild each have dark hair, but the parent has blond hair. B) A diploid plant (sporophyte) produces a spore by meiosis that gives rise to a multicellular, haploid pollen grain (gametophyte). C) A diploid animal produces gametes by meiosis, and the gametes undergo fertilization to produce a diploid zygote. D) A haploid mushroom produces gametes by mitosis, and the gametes undergo fertilization, which is immediately followed by meiosis.
B
12) A triploid cell contains three sets of homologous chromosomes. If a cell of a diploid species that normally has 42 chromosomes per cell is triploid, this cell would be expected to have which of the following sets of chromosomes? A) 63 chromosomes in 31 1/2 pairs B) 63 chromosomes in 21 sets of 3 C) 63 chromosomes, each with 3 sister chromatids D) 21 chromosome pairs and 21 unique chromosomes
B
17) Which of the life cycles is typical for most fungi and some protists? A) I only B) II only C) III only D) I and II
B
19) Which of the following characteristics do homologous chromosomes exhibit? A) They carry information for different traits. B) They carry information for the same traits. C) They carry the same alleles. D) They align on the metaphase plate in meiosis II.
B
22) Which of the following statements correctly describes a karyotype? A) It is a display of all of the cell types in an organism. B) It is an organized image of a cell's chromosomes. C) It reveals the appearance of an organism. D) It is a display of a cell's mitotic stages.
B
29) Which of the following processes occurs in meiosis but not in mitosis? A) chromosome replication B) synapsis of chromosomes C) alignment of chromosomes at the equator D) condensation of chromosomes
B
3) Asexual reproduction occurs during which of the following processes? A) meiosis B) mitosis C) fertilization D) the exchange of chromosomes between organisms of different species
B
36) Which sample of DNA might represent an animal cell in the G2 phase of the cell cycle prior to meiosis? A) I B) II C) III D) both I and II
B
41) Somatic cells of roundworms have four individual chromosomes per cell. How many chromosomes would you expect to find in an ovum from a roundworm? A) four B) two C) eight D) a diploid number
B
46) Crossing over of chromosomes normally takes place during which of the following processes? A) meiosis II B) meiosis I C) mitosis D) mitosis and meiosis II
B
47) Which of the following statements describes one characteristic of each chromosome in a cell during the entire process of meiosis I? A) Each chromosome is paired with a homologous chromosome. B) Each chromosome consists of two sister chromatids joined by a centromere. C) Each chromosome consists of a single strand of DNA. D) Each chromosome is joined with its homologous pair to form a synaptonemal complex.
B
48) During which of the following processes do homologous pairs of chromosomes align adjacent to one another at the metaphase plate of a cell? A) metaphase of mitosis B) metaphase I of meiosis C) telophase II of meiosis D) metaphase II of meiosis
B
5) Which of the following statements is correct in comparing sexual and asexual reproduction? A) Asexual reproduction, but not sexual reproduction, is characteristic of only plants and fungi. B) In sexual reproduction, individuals transmit half of their nuclear genes to each of their offspring. C) In asexual reproduction, offspring are produced by fertilization without meiosis. D) Asexual reproduction produces only haploid offspring.
B
6) At which stage of mitosis are chromosomes usually photographed in the preparation of a karyotype? A) prophase B) metaphase C) anaphase D) interphase
B
8) Eukaryotic sexual life cycles show tremendous variation. Which of the following characteristics do all sexual life cycles have in common? I. Alternation of generations II. Meiosis III. Fertilization IV. Gametes V. Spores A) I, II, and IV B) II, III, and IV C) II, IV, and V D) I, II, III, IV, and V
B
9) Which of the following processes occurs in a plant's sexual life cycle? A) sporophytes produce gametes by meiosis B) gametophytes produce gametes by mitosis C) gametophytes produce gametes by meiosis D) sporophytes produce gametes by mitosis
B
For the following questions, match the key event of meiosis with the stages listed below. I. Prophase I V. Prophase II II. Metaphase I VI. Metaphase II III. Anaphase I VII. Anaphase II IV. Telophase I VIII. Telophase II 31) Homologous chromosomes are aligned at the equator of the spindle. A) I B) II C) IV D) VI
B
37. Density-dependent inhibition is explained by which of the following? A) As cells become more numerous, they begin to squeeze against each other, restricting their size and ability to produce control factors. B) As cells become more numerous, the cell surface proteins of one cell contact the adjoining cells and they stop dividing. C) As cells become more numerous, the protein kinases they produce begin to compete with each other, such that the proteins produced by one cell essentially cancel those produced by its neighbor. D) As cells become more numerous, more and more of them enter the S phase of the cell cycle. E) As cells become more numerous, the level of waste products increases, eventually slowing down metabolism.
B) As cells become more numerous, the cell surface proteins of one cell contact the adjoining cells and they stop dividing.
4. For a newly evolving protist, what would be the advantage of using eukaryote-like cell division rather than binary fission? A) Binary fission would not allow for the formation of new organisms. B) Cell division would allow for the orderly and efficient segregation of multiple linear chromosomes. C) Cell division would be faster than binary fission. D) Cell division allows for lower rates of error per chromosome replication. E) Binary fission would not allow the organism to have complex cells.
B) Cell division would allow for the orderly and efficient segregation of multiple linear chromosomes.
11. Which of the following are primarily responsible for cytokinesis in plant cells but not in animal cells? A) kinetochores B) Golgi-derived vesicles C) actin and myosin D) centrioles and centromeres E) cyclin-dependent kinases
B) Golgi-derived vesicles
43. After which checkpoint is the cell first committed to continue the cell cycle through M? A) G₀ B) G₁ C) G₂ D) S E) previous M
B) G₁
32. Which of the following triggers the cell's passage past the G₂ checkpoint into mitosis? A) PDGF B) MPF C) protein kinase D) cyclin E) Cdk
B) MPF
68. The research team established similar lymphocyte cultures from a number of human donors, including healthy teenagers of both genders, patients already suffering from long-term bacterial infections, and elderly volunteers. They found that the increase in lymphocyte incorporation after pathogen introduction was slightly lower in some of the female teenagers and significantly lower in each of the elderly persons. They repeated the study with a larger number of samples but got the same results. 68) What might be among the research team's conclusions? A) The young women showed these results because they have poorer nutrition. B) The elderly persons' samples demonstrated their lowered immune responses. C) The young men had higher responses because they are generally healthier. D) The patient samples should have had the lowest response but did not, so the experiment is invalid. E) The elderly donor samples represent cells no longer capable of any cell division.
B) The elderly persons' samples demonstrated their lowered immune responses.
65. Nucleotides can be radiolabeled before they are incorporated into newly forming DNA and can therefore be assayed to track their incorporation. In a set of experiments, a student—faculty research team used labeled T nucleotides and introduced these into the culture of dividing human cells at specific times. 65) Which of the following questions might be answered by such a method? A) How many cells are produced by the culture per hour? B) What is the length of the S phase of the cell cycle? C) When is the S chromosome synthesized? D) How many picograms of DNA are made per cell cycle? E) When do spindle fibers attach to chromosomes?
B) What is the length of the S phase of the cell cycle?
72. 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) an animal cell in the process of cytokinesis. B) a plant cell in the process of cytokinesis. C) an animal cell in the S phase of the cell cycle. D) a bacterial cell dividing. E) a plant cell in metaphase.
B) a plant cell in the process of cytokinesis.
9. Where do the microtubules of the spindle originate during mitosis in both plant and animal cells? A) centromere B) centrosome C) centriole D) chromatid E) kinetochore
B) centrosome
77. Which of the following does not occur during mitosis? A) condensation of the chromosomes B) replication of the DNA C) separation of sister chromatids D) spindle formation E) separation of the spindle poles
B) replication of the DNA
48. What explains anchorage dependence of animal cells in vitro or in vivo? A) attachment of spindle fibers to centrioles B) response of the plasma membrane to cell cycle controls C) the makeup of the extracellular matrix of the substrate D) the binding of cell-surface phospholipids to those of adjoining cells E) the binding of cell-surface phospholipids to the substrate
B) response of the plasma membrane to cell cycle controls
17. 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
B) to allow the chromosomes to move without becoming entangled and breaking
1) If a horticulturist breeding gardenias succeeds in having a single plant with a particularly desirable set of traits, which of the following would be her most probable and efficient route to establishing a line of such plants? A) Backtrack through her previous experiments to obtain another plant with the same traits. B) Breed this plant with another plant with much weaker traits. C) Clone the plant. D) Force the plant to self-pollinate to obtain an identical one.
C
14) In a human karyotype, chromosomes are arranged in 23 pairs. If we choose one of these pairs, such as pair 14, which of the following do the two chromosomes of the pair have in common? A) length and position of the centromere only B) length, centromere position, and staining pattern only C) length, centromere position, staining pattern, and traits coded for by their genes D) They have nothing in common except that they are X-shaped.
C
16) Which of the life cycles is typical for plants and some algae? A) I only B) II only C) III only D) I and III
C
21) Which of the following statements is correct regarding the human X chromosomes? A) It is present in every somatic cell of males and females. B) It is the same size as other chromosomes and has the same number of genes. C) It carries genes that determine an individual's biological sex. D) It is referred to as an autosome.
C
24) The somatic cells of a privet shrub each contain a total of 46 chromosomes. How do the chromosomes of this plant differ from the chromosomes of humans, who also have a total of 46? A) Privet shrub cells cannot reproduce sexually. B) Privet shrub sex cells have chromosomes that can synapse with human chromosomes in the laboratory. C) Genes of privet shrub chromosomes are significantly different than those in humans. D) Privet shrubs must be metabolically more like animals than like other shrubs.
C
26) How do cells at the completion of meiosis compare with cells that are in prophase of meiosis I? A) The cells have half the number of chromosomes and half the amount of DNA. B) The cells have the same number of chromosomes and half the amount of DNA. C) The cells have half the number of chromosomes and one-fourth the amount of DNA. D) The cells have half the amount of cytoplasm and twice the amount of DNA.
C
30) When chiasmata can first be seen in cells using a microscope, which of the following processes has most likely occurred? A) meiosis II B) anaphase II C) prophase I D) the separation of homologs
C
39) If a female of this species has one chromosome 12 with a blue gene and another chromosome 12 with an orange gene, and has both number 19 chromosomes with short genes, which of the following combinations of genes will her eggs have? A) only blue short gene eggs B) only orange short gene eggs C) one half blue short and one half orange short gene eggs D) three fourths blue short and one fourth orange short gene eggs
C
42) Which of the following processes occur during meiosis but not mitosis? A) Haploid cells fuse to form diploid cells. B) Haploid cells multiply into more haploid cells. C) Diploid cells form haploid cells. D) A diploid cell combines with a haploid cell.
C
44) Which of the following statements describes a major difference between meiosis II and mitosis in a diploid animal? A) Homologous chromosomes align on the metaphase plate in meiosis II. B) Sister chromatids separate in mitosis, and homologous chromosomes separate in meiosis II. C) Meiosis II occurs in a haploid cell, while mitosis occurs in diploid cells. D) Crossing over of chromosomes takes place in meiosis II.
C
49) During which of the following phases of meiosis do centromeres split and sister chromatids migrate to opposite poles of the cell? A) anaphase I B) telophase I C) anaphase II D) telophase II
C
53) Which of the following processes occurs when homologous chromosomes cross over in meiosis I? A) Two sister chromatids get tangled, resulting in one re-sequencing its DNA. B) Two sister chromatids exchange identical pieces of DNA. C) Corresponding segments of non-sister chromatids are exchanged. D) Maternal alleles are "corrected" to be like paternal alleles and vice versa.
C
55) The bulldog ant has a diploid number of two chromosomes. Therefore, following meiosis, each daughter cell will have a single chromosome. In addition to mutations, how might genetic diversity be generated in this species? A) crossing over only B) independent assortment only C) crossing over and random fertilization D) nothing else
C
56) Which of the following processes facilitates the fastest way for organisms to adapt to a changing environment? A) mutation B) asexual reproduction C) sexual reproduction D) mitosis
C
58) In eukaryotes, genetic information is passed to the next generation by processes that include mitosis or meiosis. Which of the following explanations correctly identifies the process and supports the claim that heritable information is passed from one generation to another? A) During mitosis, DNA replication occurs twice within the cell cycle to insure a full set of chromosomes within each of the daughter cells produced. B) Mitosis, followed by cytokinesis, produces daughter cells that are genetically different from the parent cell, thus insuring variation within the population. C) In asexual reproduction, a single individual is the sole parent and passes copies of its genes to its offspring without the fusion of gametes. D) Single-celled organisms can fuse their cells, reproducing asexually through mitosis to form new cells that are not identical to the parent cell.
C
7) Which of the following statements is true of a species that has a chromosome number of 2n = 16? A) The species is diploid with 32 chromosomes per cell. B) The species has 16 sets of chromosomes per cell. C) Each diploid cell has eight homologous pairs of chromosomes. D) A gamete from this species has four chromosomes.
C
41. Cells from an advanced malignant tumor most often have very abnormal chromosomes, and often an abnormal total number of chromosomes. Why might this occur? A) Cancer cells are no longer density dependent. B) Cancer cells are no longer anchorage dependent. C) Chromosomally abnormal cells can still go through cell cycle checkpoints. D) Chromosomally abnormal cells still have normal metabolism. E) Transformation introduces new chromosomes into cells.
C) Chromosomally abnormal cells can still go through cell cycle checkpoints.
16. 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.
C) Cohesin must be cleaved enzymatically.
51. You have a series of cells, all of which were derived from tumors, and you first need to find out which ones are malignant. What could you do? A) See which ones are not overproliferating. B) Find out which ones have a higher rate of apoptosis. C) Karyotype samples to look for unusual size and number of chromosomes. D) Measure metastasis. E) Time their cell cycles.
C) Karyotype samples to look for unusual size and number of chromosomes.
40. A particular cyclin called cyclin E forms a complex with Cdk 2 (cyclin-dependent kinase 2). This complex is important for the progression of the cell from G₁ into the S phase of the cell cycle. Which of the following statements is correct? A) The amount of free cyclin E is greatest during the S phase. B) The amount of free Cdk 2 is greater during G₁ compared to the S phase. C) The amount of free cyclin E is highest during G₁. D) The amount of free Cdk 2 is greatest during G₁. E) The activity of the cyclin E/Cdk 2 complex is highest during G₂.
C) The amount of free cyclin E is highest during G₁.
27. A plant-derived protein known as colchicine can be used to poison cells by blocking the formation of the spindle. Which of the following would result if colchicine is added to a sample of cells in G₂? A) The cells would immediately die. B) The cells would be unable to begin M and stay in G₂. C) The chromosomes would coil and shorten but have no spindle to which to attach. D) The chromosomes would segregate but in a disorderly pattern. E) Each resultant daughter cell would also be unable to form a spindle.
C) The chromosomes would coil and shorten but have no spindle to which to attach.
44. Why do neurons and some other specialized cells divide infrequently? A) They no longer have active nuclei. B) They no longer carry receptors for signal molecules. C) They have been shunted into G₀. D) They can no longer bind Cdk to cyclin. E) They show a drop in MPF concentration.
C) They have been shunted into G₀.
23. What is a cleavage furrow? A) a ring of vesicles forming a cell plate B) the separation of divided prokaryotes C) a groove in the plasma membrane between daughter nuclei D) the metaphase plate where chromosomes attach to the spindle E) the space that is created between two chromatids during anaphase
C) a groove in the plasma membrane between daughter nuclei
74. One difference between cancer cells and normal cells is that cancer cells A) are unable to synthesize DNA. B) are arrested at the S phase of the cell cycle. 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 always in the M phase of the cell cycle.
C) continue to divide even when they are tightly packed together.
66. Nucleotides can be radiolabeled before they are incorporated into newly forming DNA and can therefore be assayed to track their incorporation. In a set of experiments, a student—faculty research team used labeled T nucleotides and introduced these into the culture of dividing human cells at specific times. 66) The research team used the setup to study the incorporation of labeled nucleotides into a culture of lymphocytes and found that the lymphocytes incorporated the labeled nucleotide at a significantly higher level after a pathogen was introduced into the culture. They concluded that A) the presence of the pathogen made the experiment too contaminated to trust the results. B) their tissue culture methods needed to be relearned. C) infection causes lymphocytes to divide more rapidly. D) infection causes cell cultures in general to reproduce more rapidly. E) infection causes lymphocyte cultures to skip some parts of the cell cycle.
C) infection causes lymphocytes to divide more rapidly.
42. Besides the ability of some cancer cells to overproliferate, what else could logically result in a tumor? A) metastasis B) changes in the order of cell cycle stages C) lack of appropriate cell death D) inability to form spindles E) inability of chromosomes to meet at the metaphase plate
C) lack of appropriate cell death
69. The research team established similar lymphocyte cultures from a number of human donors, including healthy teenagers of both genders, patients already suffering from long-term bacterial infections, and elderly volunteers. They found that the increase in lymphocyte incorporation after pathogen introduction was slightly lower in some of the female teenagers and significantly lower in each of the elderly persons. They repeated the study with a larger number of samples but got the same results. 69) Which of the following investigations might be most productive to show what the data on the teenagers might indicate? A) test male teenagers B) test teenagers who say they are not sexually active C) test female teens at different times in their menstrual cycles D) test relatives of the teens previously tested E) test teenagers from different school systems
C) test female teens at different times in their menstrual cycles
75. The decline of MPF activity at the end of mitosis is due to A) the destruction of the protein kinase Cdk. B) decreased synthesis of Cdk. C) the degradation of cyclin. D) the accumulation of cyclin. E) synthesis of DNA.
C) the degradation of cyclin.
11) A particular organism has 46 chromosomes in its karyotype. Which of the following statements is correct regarding this organism? A) It must be human. B) It must be an animal. C) It reproduces sexually. D) It produces gametes with 23 chromosomes.
D
2) Which of the following statements defines a genome? A) the complete set of an organism's polypeptides B) the complete set of a species' polypeptides C) a karyotype D) the complete set of an organism's genes and other DNA sequences
D
20) Many organisms spend most of their life cycle in the diploid state. If meiosis produces haploid cells, how is the diploid number restored for these types of organisms? A) by DNA replication B) through the transcription of DNA to RNA C) by synapsis of the homologous pairs of chromosomes during prophase of meiosis I D) by fertilization
D
25) Which of the following statements describes the chromosomal makeup of each daughter cell after telophase of meiosis I? A) The cells are diploid, and the chromosomes are each composed of a single chromatid. B) The cells are diploid, and the chromosomes are each composed of two chromatids. C) The cells are haploid, and the chromosomes are each composed of a single chromatid. D) The cells are haploid, and the chromosomes are each composed of two chromatids.
D
28) During which of the following processes do sister chromatids separate from each other? A) during meiosis I only B) during meiosis II only C) during both mitosis and meiosis I D) during both mitosis and meiosis II
D
32) Centromeres of sister chromatids disjoin and chromatids separate. A) III B) IV C) V D) VII
D
34) Which diagram represents anaphase II of meiosis? A) I B) III C) IV D) V
D
4) Quaking aspen trees can send out underground stems for asexual reproduction. Sexual reproduction is not as common, but when it does happen, the haploid gametes have 19 chromosomes. How many chromosomes are in the cells of the underground stems? A) 9 B) 10 C) 19 D) 38
D
40) A female with a paternal set of one orange and one long gene chromosome and a maternal set comprised of one blue and one short gene chromosome would be expected to produce which of the following types of eggs after meiosis? A) All eggs will have maternal types of gene combinations. B) All eggs will have paternal types of gene combinations. C) Half the eggs will have maternal and half will have paternal combinations. D) Each egg has a one-fourth chance of having either blue long, blue short, orange long, or orange short combinations.
D
43) During which of the following phases of meiosis do homologous chromosomes separate? A) anaphase II B) prophase I C) mitosis D) anaphase I
D
51) For a species with a haploid number of 23 chromosomes, how many different combinations of maternal and paternal chromosomes are possible for the gametes based on the independent assortment of chromosomes during meiosis? A) 23 B) 46 C) about 1,000 D) about 8 million
D
59) Genetic variation leads to genetic diversity in populations and is the raw material for evolution. Biological systems have multiple processes, such as reproduction, that affect genetic variation. They are evolutionarily conserved and shared by various organisms. Which of the following statements best represents the connection between reproduction and evolution? A) Plants that use sexual reproduction are rare since this type of reproduction in plants does not contribute to genetic diversity. B) In order to increase genetic diversity for evolution in sexually reproducing organisms, mutations must occur in the zygote after fertilization. C) Since prokaryotic organisms reproduce asexually, there is no mechanism for them to add genetic diversity for evolution. D) Sexual reproduction increases genetic variation because random mutations can be shuffled between organisms.
D
Refer to the information and figure below to answer the following questions. A certain (hypothetical) organism is diploid, has either blue or orange wings as the consequence of one of its genes on chromosome 12, and has either long or short antennae as the result of a second gene on chromosome 19, as shown in the figure. 38) A certain female's number 12 chromosomes both have the blue gene and number 19 chromosomes both have the long gene. As cells in her ovaries undergo meiosis, which of the following combinations of genes and chromosomes will her eggs have? A) either two number 12 chromosomes with blue genes or two with orange genes B) either two number 19 chromosomes with long genes or two with short genes C) either one blue or one orange gene in addition to either one long or one short gene D) one chromosome 12 with one blue gene and one chromosome 19 with one long gene
D
15. A group of cells is assayed for DNA content immediately following mitosis and is found to have an average of 8 picograms of DNA per nucleus. How many picograms would be found at the end of S and the end of G₂? A) 8; 8 B) 8; 16 C) 16; 8 D) 16; 16 E) 12; 16
D) 16; 16
Starting with a fertilized egg (zygote), a series of five cell divisions would produce an early embryo with how many cells? A) 4 B) 8 C) 16 D) 32 E) 64
D) 32
22. Which of the following is (are) required for motor proteins to function in the movement of chromosomes toward the poles of the mitotic spindle? A) intact centromeres B) an MTOC (microtubule organizing center) C) a kinetochore attached to the metaphase plate D) ATP as an energy source E) synthesis of cohesin
D) ATP as an energy source
14. Measurements of the amount of DNA per nucleus were taken on a large number of cells from a growing fungus. The measured DNA levels ranged from 3 to 6 picograms per nucleus. In which stage of the cell cycle did the nucleus contain 6 picograms of DNA? A) G₀ B) G₁ C) S D) G₂ E) M
D) G₂
45. Which of the following most accurately describes a cyclin? A) It is present in similar concentrations throughout the cell cycle. B) It is activated to phosphorylate by complexing with a Cdk. C) It decreases in concentration when MPF activity increases. D) It activates a Cdk molecule when it is in sufficient concentration. E) It activates a Cdk when its concentration is decreased.
D) It activates a Cdk molecule when it is in sufficient concentration.
49. A research team began a study of a cultured cell line. Their preliminary observations showed them that the cell line did not exhibit either density-dependent inhibition or anchorage dependence. What could they conclude right away? A) The cells originated in the nervous system. B) The cells are unable to form spindle microtubules. C) They have altered series of cell cycle phases. D) The cells show characteristics of tumors. E) They were originally derived from an elderly organism.
D) The cells show characteristics of tumors.
18. Which of the following best describes how chromosomes move toward the poles of the spindle during mitosis? A) The chromosomes are "reeled in" by the contraction of spindle microtubules. B) Motor proteins of the kinetochores move the chromosomes along the spindle microtubules. C) Nonkinetochore spindle fibers serve to push chromosomes in the direction of the poles. D) The chromosomes are "reeled in" by the contraction of spindle microtubules, and motor proteins of the kinetochores move the chromosomes along the spindle microtubules. E) The chromosomes are "reeled in" by the contraction of spindle microtubules, motor proteins of the kinetochores move the chromosomes along the spindle microtubules, and nonkinetochore spindle fibers serve to push chromosomes in the direction of the poles.
D) The chromosomes are "reeled in" by the contraction of spindle microtubules, and motor proteins of the kinetochores move the chromosomes along the spindle microtubules.
63. Several organisms, primarily protists, have what are called intermediate mitotic organization. 63) These protists are intermediate in what sense? A) They reproduce by binary fission in their early stages of development and by mitosis when they are mature. B) They never coil up their chromosomes when they are dividing. C) They use mitotic division but only have circular chromosomes. D) They maintain a nuclear envelope during division. E) None of them form spindles.
D) They maintain a nuclear envelope during division.
24. Which of the following proteins are involved in binary fission as well as eukaryotic mitotic division? A) cyclins B) Cdks C) MPF D) actin and tubulin E) cohesins
D) actin and tubulin
62. The best conclusion concerning delta is that the cells A) contain no DNA. B) contain no RNA. C) contain only one chromosome that is very short. D) are actually in the G₀ phase. E) divide in the G₁ phase.
D) are actually in the G₀ phase.
67. Nucleotides can be radiolabeled before they are incorporated into newly forming DNA and can therefore be assayed to track their incorporation. In a set of experiments, a student—faculty research team used labeled T nucleotides and introduced these into the culture of dividing human cells at specific times. 67) Once they had determined which cells were dividing, the team wanted to use a non-radioactive method to track whether various physiological factors (such as food or body temperature) affect the action of the pathogen. Which of the following would be effective, simple, and safe? A) measuring picograms of DNA B) measuring numbers of chromosomes C) measuring numbers of chromatids D) counting the frequency of cells in mitosis E) counting newly formed plasma membranes
D) counting the frequency of cells in mitosis
30. Which of the following is a protein synthesized at specific times during the cell cycle that associates with a kinase to form a catalytically active complex? A) PDGF B) MPF C) protein kinase D) cyclin E) Cdk
D) cyclin
12. In which group of eukaryotic organisms does the nuclear envelope remain intact during mitosis? A) seedless plants B) dinoflagellates C) diatoms D) dinoflagellates and diatoms only E) seedless plants, dinoflagellates, and diatoms
D) dinoflagellates and diatoms only
54. If the cell whose nuclear material is shown in Figure 12.2 continues toward completion of mitosis, which of the following events would occur next? A) cell membrane synthesis B) spindle fiber formation C) nuclear envelope breakdown D) formation of telophase nuclei E) synthesis of chromatids
D) formation of telophase nuclei
28. What causes the decrease in the amount of cyclin at a specific point in the cell cycle? A) an increase in production once the restriction point is passed B) the cascade of increased production once its protein is phosphorylated by Cdk C) the changing ratio of cytoplasm to genome D) its destruction by a process initiated by the activity of its complex with a cyclin E) the binding of PDGF to receptors on the cell surface
D) its destruction by a process initiated by the activity of its complex with a cyclin
19. Which of the following is a function of those spindle microtubules that do not attach to kinetochores? A) maintaining an appropriate spacing among the moving chromosomes B) producing a cleavage furrow when telophase is complete C) providing the ATP needed by the fibers attached to kinetochores D) maintaining the region of overlap of microtubules in the cell's center E) pulling the poles of the spindles closer to one another
D) maintaining the region of overlap of microtubules in the cell's center
7. If cells in the process of dividing are subjected to colchicine, a drug that interferes with the formation of the spindle apparatus, at which stage will mitosis be arrested? A) anaphase B) prophase C) telophase D) metaphase E) interphase
D) metaphase
13. 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.
D) prevents shortening of microtubules.
25. Using which of the following techniques would enable your lab group to distinguish between a cell in G₂ and a cell from the same organism in G₁? A) fluorescence microscopy B) electron microscopy C) spectrophotometry D) radioactive-labeled nucleotides E) labeled kinetochore proteins
D) radioactive-labeled nucleotides
5. Suppose a biologist can separate one of a dozen pieces of chromatin from a eukaryotic (animal) nucleus. It might consist of which of the following? A) one-twelfth of the genes of the organism B) two chromosomes, each with six chromatids C) a single circular piece of DNA D) two long strands of DNA plus proteins E) two chromatids attached together at a centromere
D) two long strands of DNA plus proteins
Eukaryotic chromosomes are composed of which of the following macromolecules? - DNA and proteins - DNA and phospholipids - DNA only - DNA and RNA
DNA and proteins
Which of the following processes occur during meiosis but not mitosis? - Diploid cells form haploid cells. - Haploid cells fuse to form diploid cells. - A diploid cell combines with a haploid cell. - Haploid cells multiply into more haploid cells.
Diploid cells form haploid cells.
31. Which of the following is a protein maintained at constant levels throughout the cell cycle that requires cyclin to become catalytically active? A) PDGF B) MPF C) protein kinase D) cyclin E) Cdk
E) Cdk
39. Which of the following describe(s) cyclin-dependent kinase (Cdk)? A) Cdk is inactive, or "turned off," in the presence of cyclin. B) Cdk is present throughout the cell cycle. C) Cdk is an enzyme that attaches phosphate groups to other proteins. D) Cdk is inactive, or "turned off," in the presence of cyclin and it is present throughout the cell cycle. E) Cdk is present throughout the cell cycle and is an enzyme that attaches phosphate groups to other proteins.
E) Cdk is present throughout the cell cycle and is an enzyme that attaches phosphate groups to other proteins.
50. For a chemotherapeutic drug to be useful for treating cancer cells, which of the following is most desirable? A) It is safe enough to limit all apoptosis. B) It does not alter metabolically active cells. C) It only attacks cells that are density dependent. D) It interferes with cells entering G₀. E) It interferes with rapidly dividing cells.
E) It interferes with rapidly dividing cells.
33. The cyclin component of MPF is destroyed toward the end of which phase? A) G₀ B) G₁ C) S D) G₂ E) M
E) M
36. A mutation results in a cell that no longer produces a normal protein kinase for the M phase checkpoint. Which of the following would likely be the immediate result of this mutation? A) The cell would prematurely enter anaphase. B) The cell would never leave metaphase. C) The cell would never enter metaphase. D) The cell would never enter prophase. E) The cell would undergo normal mitosis, but fail to enter the next G₁ phase.
E) The cell would undergo normal mitosis, but fail to enter the next G₁ phase
46. All cell cycle checkpoints are similar in which way? A) They respond to the same cyclins. B) They utilize the same Cdks. C) They give the go-ahead signal to progress to the next checkpoint. D) They each have only one cyclin/Cdk complex. E) They activate or inactivate other proteins.
E) They activate or inactivate other proteins.
64. Several organisms, primarily protists, have what are called intermediate mitotic organization. A) They represent a form of cell reproduction which must have evolved completely separately from those of other organisms. B) They demonstrate that these species are not closely related to any of the other protists and may well be a different kingdom. C) They rely on totally different proteins for the processes they undergo. D) They may be more closely related to plant forms that also have unusual mitosis. E) They show some but not all of the evolutionary steps toward complete mitosis.
E) They show some but not all of the evolutionary steps toward complete mitosis.
38. Which of the following is true concerning cancer cells? A) They do not exhibit density-dependent inhibition when growing in culture. B) When they stop dividing, they do so at random points in the cell cycle. C) They are not subject to cell cycle controls. D) When they stop dividing, they do so at random points in the cell cycle, and they are not subject to cell cycle controls. E) When they stop dividing, they do so at random points in the cell cycle; they are not subject to cell cycle controls; and they do not exhibit density-dependent inhibition when growing in culture.
E) When they stop dividing, they do so at random points in the cell cycle; they are not subject to cell cycle controls; and they do not exhibit density-dependent inhibition when growing in culture.
79. The drug cytochalasin B blocks the function of actin. Which of the following aspects of the cell cycle would be most disrupted by cytochalasin B? A) spindle formation B) spindle attachment to kinetochores C) DNA synthesis D) cell elongation during anaphase E) cleavage furrow formation and cytokinesis
E) cleavage furrow formation and cytokinesis
34. Proteins that are involved in the regulation of the cell cycle, and that show fluctuations in concentration during the cell cycle, are called A) ATPases. B) kinetochores. C) kinases. D) proton pumps. E) cyclins.
E) cyclins.
6) At which phase are centrioles beginning to move apart in animal cells? A) telophase B) anaphase C) prometaphase D) metaphase E) prophase
E) prophase
71. A student is looking through his light microscope (~450 X) at a squashed and stained onion root tip. Some, but not all, of the cells have clearly visible chromosome strands. 71) When the cell has just completed telophase, which of the following does he see? A) a clear area in the center of the cell B) chromosomes clustered at the poles C) individual chromatids separating D) formation of vesicles at the midline E) two small cells with chromatin
E) two small cells with chromatin
Which of the following events happens at the conclusion of meiosis I? - Sister chromatids are separated. - Homologous chromosomes of a pair are separated from each other. - Four daughter cells are formed. - The chromosome number per cell remains the same.
Homologous chromosomes of a pair are separated from each other.
Refer to the drawings in the figure below of a single pair of homologous chromosomes as they might appear during various stages of either mitosis or meiosis, and answer the following question(s). Which diagram represents anaphase I of meiosis?
I
Which of the following statements describes the chromosomal makeup of each daughter cell after telophase of meiosis I? - The cells are diploid, and the chromosomes are each composed of two chromatids. - The cells are haploid, and the chromosomes are each composed of a single chromatid. - The cells are haploid, and the chromosomes are each composed of two chromatids. - The cells are diploid, and the chromosomes are each composed of a single chromatid.
The cells are haploid, and the chromosomes are each composed of two chromatids.
Which of the following characteristics do homologous chromosomes exhibit? - They carry the same alleles. - They carry information for different traits. - They align on the metaphase plate in meiosis II. - They carry information for the same traits.
They carry information for the same traits.
A cleavage furrow is ________. - a groove in the plasma membrane between daughter nuclei - a ring of vesicles forming a cell plate - the space that is created between two chromatids during anaphase - the separation of divided prokaryotes
a groove in the plasma membrane between daughter nuclei
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 plant cell in the process of cytokinesis
Metaphase is characterized by ________. - separation of sister chromatids - alignment of chromosomes on the equator of the cell - separation of the centromeres - cytokinesis
alignment of chromosomes on the equator(mid-point) of the cell
___________ is the phase of mitosis when the chromatids separate. - anaphase - metaphase - interphase - prophase
anaphase
During which of the following phases of meiosis do homologous chromosomes separate? anaphase I mitosis anaphase II prophase I
anaphase I
Cells that acquire the ability to divide indefinitely are undergoing transformation. If abnormal cells remain only at the original site, the lump is considered ______________. - benign - malignant - metastatic - invasive
benign
__________ are the structures that hold the two chromatids together in a doubled chromosome - centromere - cytokinesis - cell plate - cleavage furrow
centromere
What is the name of the microtubule-organizing center found in animal cells as an identifiable structure present during all phases of the cell cycle? centromere kinetochore centriole centrosome
centrosome
What two components constitute an active MPF? - a growth factor and mitotic factor - cyclin and tubulin - ATP synthetase and a protease - cyclin and a cyclin-dependent kinase
cyclin and a cyclin-dependent kinase
___________ is the division of the cytoplasm - cytokinesis - mitosis - interphase - centromere
cytokinesis
______ is the phase of the cell cycle when DNA replicates. - interphase - prophase - metaphase - telophase
interphase
______ is the phase of mitosis when the chromosomes align on the equator - metaphase - interphase - anaphase - prophase
metaphase
At which phase of the cell cycle do centrioles begin to move apart in animal cells and early mitotic spindle forms? - anaphase - metaphase - prophase - telophase
prophase
__________ is the phase of mitosis when the chromosomes first appear - prophase - interphase - metaphase - anaphase
prophase
__________ is the phase of mitosis when the nucleolus disappears - prophase - anaphase - telophase - anaphase
prophase
___________ is the phase of mitosis when the spindle fibers are formed - prophase - metaphase - anaphase - telophase
prophase
Which of the following events occurs during interphase of the cell cycle? - Separation of the spindle poles - Condensation of the chromosomes - Spindle formation - replication of the DNA
replication of the DNA
Which of the following processes occurs in meiosis but not in mitosis? - synapsis of chromosomes - condensation of chromosomes - chromosome replication - alignment of chromosomes at the equator
synapsis of chromosomes
_______ is the phase of mitosis when the cleavage furrow visibly appears - telephase - anaphase - metaphase - prophase
telephase
__________ is the phase of mitosis when the spindle fibers disappear - telophase - prophase - interphase - anaphase
telophase
___________ is the phase of mitosis when the cell plate visibly appears - telophase - prophase - metaphase - anaphase
telophase
Which of the following statements defines a genome? - the complete set of a species' polypeptides - a karyotype - the complete set of an organism's genes and other DNA sequences - the complete set of an organism's polypeptides
the complete set of an organism's genes and other DNA sequences
Somatic cells of roundworms have four individual chromosomes per cell. How many chromosomes would you expect to find in an ovum from a roundworm? - eight - four - Two - a diploid number
two