MITOSIS & MEOSIS
True/False
Indicate whether the statement is true or false.
____ 1. Diffusion over large distances is slow and inefficient because it relies on random movement of molecules and ions.
____ 2. The cell cycle is divided into interphase and mitosis.
____ 3. During prophase in an onion root tip cell, centrioles migrate to the poles of the cell.
____ 4. In plant cells, cytokinesis begins with a furrow that pinches the cell.
____ 5. Stem cells are only of one type: embryonic.
____ 6. Embryonic stem cells are found in various tissues in the body and might be used to maintain and repair the same kind of tissue in which they are found.
____ 7. A gamete has one-half the number of chromosomes of a regular body cell.
____ 8. Homologous chromosomes are two chromosomes with identical DNA sequences.
____ 9. Recent research suggests that beneficial mutations accumulate faster when species undergo sexual reproduction rather than asexual reproduction.
____ 10. During meiosis, chromosome number is reduced through three rounds of cell division.
____ 11. Sexual reproduction would be more advantageous than asexual reproduction for organisms living in an environment that is diverse and undergoes frequent changes.
____ 12. Mendel’s work on garden pea plants resulted in the discovery that genetic traits of parents always blend together in subsequent generations.
____ 13. In humans, the ability to roll one’s tongue is a dominant trait. Therefore, a tongue roller can only have children who are also tongue rollers.
____ 14. The separation of genes during crossing over occurs more frequently between genes that are far apart on a chromosome than for genes that are close together.
____ 15. Polyploidy is more common in plants than animals.
____ 16. Polyploid plants such as coffee and strawberries are often less healthy and smaller than diploid plants of the same species.
____ 17. During meiosis I, homologus chromosome pairs are separated when the centromeres split apart.
____ 18. Meiosis occurs during both sexual reproduction and asexual reproduction.
____ 19. Gregor Mendel’s research supports the idea each organism carries a pair of alleles.
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____ 20. By the end of prophase, each of the following has occurred except ____.
a. / tighter coiling of the chromosomesb. / breaking down of the nuclear envelope
c. / disappearing of the nucleolus
d. / lining up of chromosomes in the cell
____ 21. The chromosomes shown in Figure 9-1 are in which state of mitosis?
Figure 9-1
a. / prophase / c. / anaphaseb. / metaphase / d. / telophase
Figure 9-2
____ 22. Which of the cells depicted in the line graph in Figure 9-2 are most likely cancerous?
a. / A / c. / Cb. / B / d. / D
____ 23. If cancer is present, what is the likely explanation for what happened to the cells depicted in the curves labeled B and D in Figure 9-2?
a. / They thrived with the cancerous cells.b. / They were harmed by radiation therapy.
c. / They died off due to natural causes.
d. / They died off because the cancerous cells deprived them of nutrients.
____ 24. Which of the following does not occur as a cell grows larger and larger in size?
a. / difficulty obtaining nutrientsb. / difficulty eliminating wastes
c. / ratio of surface area to volume increases
d. / diffusion across the cell membrane is impaired
Figure 9-3
____ 25. Which of the graphs in Figure 9-3 shows the correct changes in the amount of DNA in a cell as it moves through one cell cycle?
a. / A / c. / Cb. / B / d. / D
____ 26. Why is the synthesis stage called this?
a. / because protein synthesis is taking placeb. / because DNA synthesis is taking place
c. / because it combines several smaller stages into one
d. / because the chromosomes come together
____ 27. Which of these has occurred by the end of prophase?
a. / Sister chromatids are separated.b. / The spindle is beginning to form.
c. / The cell membrane has begun to pinch inward.
d. / The nuclear membrane has disappeared.
Figure 9-4
____ 28. Figure 9-4 illustrates which stage of mitosis?
a. / anaphase / c. / prophaseb. / metaphase / d. / telophase
____ 29. How is the alignment of chromosomes, shown in Figure 9-4, on the equatorial plate of the cell maintained?
a. / They are always located there, since that is where the nucleus was.b. / Tension between opposite spindle fibers pulls them there.
c. / The pressure of the cytoplasm moves them there.
d. / The chromosomes are attracted to each other and meet there.
____ 30. Which of the following occurs in telophase?
a. / chromosomes condenseb. / chromosomes line up
c. / chromosomes move to opposite poles
d. / chromosomes relax
____ 31. A cell has 12 chromosomes. How many chromosomes will each daughter cell have?
a. / 4 / c. / 12b. / 6 / d. / 24
____ 32. A cell that is undergoing mitosis is examined with a light microscope. An observation that would allow for identification of the cell as an animal cell rather than a plant cell would be
a. / the centrioles migrating.b. / the chromosome pairs separating from each other.
c. / the chromosomes twisting about each other.
d. / the nucleoli disappearing.
____ 33. The cell cycle is regulated by
a. / cyclins / c. / hormonesb. / enzymes / d. / sugars
____ 34. Cancer cells can reproduce rapidly because they
a. / are smaller than normal cells. / c. / undergo mitosis fasterb. / bypass interphase. / d. / spend less time in interphase
____ 35. What is cancer caused by?
a. / cell-membrane damage / c. / mutationb. / metabolic poisoning / d. / immune-system damage
____ 36. Prokaryotes divide by binary fission, a form of asexual reproduction in which
a. / the nucleus divides into two nuclei.b. / the number of chromosomes in the cell is reduced.
c. / a cell divides into two cells with identical genetic information.
d. / spindle fibers attach to the poles of the cell.
____ 37. It is often said that normal cells change into cancerous cells frequently in our bodies. Which of the following explanations accounts for the relative rarity of cancer?
a. / The cancerous cells die on their own.b. / The DNA repair system fixes the mutation that causes cancer.
c. / The cancer cells grow only very slowly at first.
d. / The cancerous cells are normally crowded out by normal cell growth.
____ 38. What is the role of cyclin-dependent kinases in the cell cycle?
a. / They stop the cycle if something has gone wrong.b. / They catalyze the condensation of the chromosomes.
c. / They provide the energy for the actions of the spindle fibers.
d. / They initiate various stages of the cell cycle.
Figure 9-5
____ 39. The cell in Figure 9-5 is undergoing mitosis. Which stage of mitosis will follow this one?
a. / anaphase / c. / prophaseb. / metaphase / d. / telophase
____ 40. Which checkpoint has this cell just passed?
a. / near the end of gap 1, monitoring DNA damageb. / during the S stage
c. / during the gap 2 stage
d. / during mitosis, monitoring spindle formation
____ 41. DNA replication occurs during
a. / anaphase. / c. / metaphase.b. / interphase. / d. / prophase.
____ 42. If you were studying the causes of cancer, which topic might interest you?
a. / cyclin-dependent kinases / c. / spindle-fiber structureb. / centromere structure / d. / cell membranes
____ 43. Which of the phases of mitosis has the shortest duration?
a. / anaphase / c. / metaphaseb. / cytokinesis / d. / prophase
____ 44. A cell that undergoes repeated mitosis without cytokinesis would have
a. / many daughter cells. / c. / many nuclei.b. / fewer chromosomes. / d. / cancerous properties.
____ 45. Why is it important for the chromosomes to condense during mitosis?
a. / to facilitate DNA replicationb. / to facilitate chromosome movement
c. / to facilitate cytokinesis
d. / to facilitate spindle formation
____ 46. The typical growth period of a cell occurs during which stage of the cell cycle?
a. / Gap 1 / c. / synthesisb. / Gap 2 / d. / mitosis
____ 47. Some cancers have a genetic component to them, if a parent has a cancer the children are more likely than the average population to develop the cancer. Why might this be?
a. / Cancers require more than one mutation to occur.b. / Cancers are inherited but remain dormant until a certain age.
c. / Parents and children are often exposed to similar environmental factors.
d. / Cancers are often recessive traits and require alleles from both parents.
____ 48. Colchicine is a chemical that when applied to a cell during mitosis can be used to “freeze” cells in metaphase by preventing the chromosomes from moving away from the metaphase plate. What part of the cell does colchicine most likely affect?
a. / chromosome structure / c. / nuclear membraneb. / spindle fibers / d. / cell membrane
____ 49. A stem cell has potential medical uses because it
a. / undergoes mitosis.b. / is not specialized in structure and function.
c. / is similar to a cancer cell, providing a study system.
d. / undergoes apoptosis.
____ 50. The numbers in Figure 10-1 represent the chromosome number found in each of the dog cells shown. The processes that are occurring at A and B are ____.
Figure 10-1
a. / mitosis and fertilization / c. / mitosis and pollinationb. / meiosis and fertilization / d. / meiosis and pollination
____ 51. A white mouse whose parents are both white produces only brown offspring when mated with a brown mouse. The white mouse is most probably ____.
a. / homozygous recessive / c. / homozygous dominantb. / heterozygous / d. / haploid
____ 52. In chickens, rose comb (R) is dominant to single comb (r). A homozygous rose-combed rooster is mated with a single-combed hen. All of the chicks in the F1 generation were kept together as a group for several years. They were allowed to mate only within their own group. What is the expected phenotype of the F2 chicks?
a. / 100% rose combb. / 75% rose comb and 25% single comb
c. / 100% single comb
d. / 50% rose comb and 50% single comb
____ 53. In mink, brown fur color is dominant to silver-blue fur color. If a homozygous brown mink is mated with a silver-blue mink and 8 offspring are produced, how many would be expected to be silver-blue?
a. / 0 / c. / 6b. / 3 / d. / 8
____ 54. The diagram in Figure 10-2 shows a diploid cell with two homologous pairs of chromosomes. Due to independent assortment, the possible allelic combinations that could be found in gametes produced by the meiotic division of this cell are ____.
Figure 10-2
a. / Bb, Dd, BB, and DD / c. / BbDd and BDbdb. / BD, bD, Bd, and bd / d. / Bd and bD only
____ 55. Using Figure 10-3, which process would result in the formation of chromosome C from chromosomes A and B?
Figure 10-3
a. / asexual reproduction / c. / crossing overb. / independent assortment / d. / segregation
Figure 10-5
____ 56. What is the genotype of generation 1 in Figure 10-5?
a. / II / c. / iib. / Ii / d. / I
Figure 10-7
____ 57. What fraction of this cross will be recessive for both traits?
a. / 1/2 / c. / 1/8b. / 1/4 / d. / 1/16
Figure 10-8
____ 58. In Figure 10-8, which set of chromatids illustrates the result of a single crossover of the homologous chromosomes?
a. / A / c. / Cb. / B / d. / D
____ 59. In Figure 10-8, which set of chromatids will result if each chromatid crossed with a nonsister chromatid?
a. / A / c. / Cb. / B / d. / D
____ 60. Which event during meiosis leads to a reduction in chromosome number from 2n to n?
a. / Pairs of homologous chromosomes line up at the equator.b. / DNA undergoes replication.
c. / Homologous chromosomes travel to opposite sides of the cell.
d. / Sister chromatids are pulled apart at the centromere.
____ 61. Crossing over would most likely occur during which stage of the cell cycle?
a. / when DNA is being replicatedb. / when homologous chromomosomes line up in pairs
c. / when centromeres are separated
d. / when cytokinesis begins
____ 62. Which is the best description of the events that take place during anaphase II?
a. / The replicated chromosomes become visible.b. / Homologous chromosomes line up along the equator.
c. / Sister chromatids are separated and pulled to opposite sides of the cell.
d. / Homologous pairs are separated and pulled to opposite sides of the cell.
____ 63. What is the role of the spindle fibers?
a. / to join homologous chromosomes togetherb. / to store nucleotides prior to DNA synthesis
c. / to initiate the formation of the nuclear membrane
d. / to move chromosomes in the cell
____ 64. The typical human body cell contains 46 chromosomes. How many chromosomes are found in a typical human sperm?
a. / 23 / c. / 46b. / 45 / d. / 92
____ 65. Suppose an animal is heterozygous AaBb, and the traits are not linked. When meiosis occurs, what is the total number of possible combinations of gametes that can be made for these traits?