Q50. Which of the following events must happen PRIOR to the start of mitosis?
A. The nuclear envelope dissolves.
B. The cell condenses its DNA into chromosomes.
C. The cell attaches chromosomes to the spindle.
D. The cell replicates its DNA.
Q51. How many sister chromatids does the cell depicted below have?
Blank ____ chromatids
Q53. In what order do events occur during mitosis?
A. chromosomes condense, nuclear envelope dissolves, chromosomes at midline, sister chromatids separate ,cytokinesis
B. chromosomes condense, chromosomes at midline, sister chromatids separate , nuclear envelope dissolves, cytokinesis
C.cytokinesis → chromosomes condense → nuclear envelope dissolves → sister chromatids separate → chromosomes at midline
D.cytokinesis → chromosomes at midline → chromosomes condense → nuclear envelope dissolves → sister chromatids separate
The cell below, whose sister chromatids are numbered, is undergoing mitosis. Use this information to answer the next FOUR questions (Q53 through Q56).
Q53. What is happening in the cell above?
A. The cell is in metaphase. Chromosomes are not condensed, the nuclear envelope has dissolved, and the spindle has not yet formed.
B. The cell is in metaphase. Chromosomes are condensed, the nuclear envelope has dissolved, and the spindle is attached to all chromosomes.
C. The cell is in prometaphase. Chromosomes are not condensed, the nuclear envelope has dissolved, and the spindle is not attached to any chromosomes.
D. The cell is in prometaphase. Chromosomes are condensed, the nuclear envelope has dissolved, and the spindle is attaching to chromosomes.
Q54. For the cell shown above in the middle of mitosis, which statement below represents a likely combination of chromatids in the two daughter cells that will be produced?
A. One daughter contains chromatids 1, 2, 3, 4. The other daughter contains chromatids 5, 6, 7, 8.
B. One daughter contains chromatids 1, 2, 5, 6. The other daughter contains chromatids 3, 4, 7, 8.
C. One daughter contains chromatids 1, 3, 5, 7. The other daughter contains chromatids 2, 4, 6, 8.
D.At this stage in mitosis, any combination of four chromatids per daughter cell is possible.
Q55. What will happen during the NEXT stage of mitosis to the chromosomes in the cell shown above, and why?
A. All chromosomes will move toward the midline of the cell, because they are being pushed there by the spindle.
B. All chromosomes will move toward the midline of the cell, because they are being pulled there by the spindle.
C. Half the chromatids will move to one side of the cell's midline and half to the other, because they are being pushed to opposite sides by the spindle.
D. Half the chromatids will move to one side of the cell's midline and half to the other, because they are being pulled to opposite sides by the spindle.
Q56. Could the cell shown above proceed past the metaphase checkpoint exactly in its current state, without any additional changes in the spindle or chromosomes?
A. No, because each spindle pole has extra microtubules that are not attached to chromosomes.
B. No, because not all chromosomes are fully attached to the spindle or lined up along the midline.
C.Yes, because each chromosome is attached to the spindle and they are lined up on the midline.
D. Yes, because each chromosome has sister chromatids, allowing cohesin to dissolve.
Q57. Which of the following statements is FALSE?
A.The nuclear envelope dissolves in prometaphase and reforms in telophase.
B. In prophase, DNA condenses into chromosomes.
C. The spindle forms and attaches to chromosomes in metaphase.
D. In anaphase, each sister chromatid moves toward the spindle pole to which it is attached.
Q58. The drug colchicine prevents the spindle's microtubules from forming or growing. What would happen in mitosis to a cell that was given colchicine throughout mitosis?
A. The chromosomes would not condense.
B. The nuclear envelope would not dissolve.
C. The chromosomes would not line up for metaphase.
D.The chromosomes would line up for metaphase but would not pull apart in anaphase.
Q59. Would a cell that was missing the kinetochores on one of its chromosomes be able to get past the metaphase checkpoint?
A. No, because the spindle could not attach to that chromosome and pull it to the midline.
B.No, because cohesin on that chromosome could not dissolve.
C. No, because kinetochores are necessary for sister chromatids to be held together.
D. Yes, because kinetochores do not have any effect on the metaphase checkpoint.