1.6 Cell Division [65 marks]
1. In the chimpanzee (Pan troglodytes), the haploid number of chromosomes[1 mark]
is 24. How many sister chromatids are present in the G2 phase of a
somatic cell, such as a cell in the bone marrow of the chimpanzee?
A. 12
B. 24
C. 48
D. 96
2. Cisplatin is an anti-cancer drug that prevents tumour cells from dividing [1 mark]
by mitosis as it inhibits cell processes at stage S of interphase. How does
cisplatin prevent cancer cells from dividing?
A. It inhibits the replication of DNA.
B. It inhibits the growth of the spindle fibres.
C. It prevents the breakdown of the nuclear membrane.
D. It prevents the condensation of chromosomes.
,3. The graph shows the mitotic index in the roots of lentil plants at different [1 mark]
distances from the end of the root.
[Source: Physiologia Plantarum, Volume 105, Issue 1, January 1999, Pages 171–
178, Effect of microgravity on the cell cycle
in the lentil root F. Yu, D. Driss-Ecole, J. Rembur, V. Legué, G. Perbal Wiley Online
Library: https://onlinelibrary.wiley.
com/doi/abs/10.1034/j.1399-3054.1999.105125.x]
What can be deduced from the graph?
A. As the distance from the end of the root increases, more cells are undergoing
mitosis.
B. At 0.5 mm from the end of the root, most of the cells are in prophase.
C. There were fewer cells observed at 1.5 mm than at 0.5 mm.
D. As the distance from the end of the root increases, the percentage of cells in
interphase increases.
, 4. A tissue sample was examined under the microscope in order to [1 mark]
determine a mitotic index. The number of cells in each stage of the cell
cycle was determined and the data were entered into a table.
What is the mitotic index?
A. 0.125
B. 0.25
C. 0.75
D. 1.00
1. In the chimpanzee (Pan troglodytes), the haploid number of chromosomes[1 mark]
is 24. How many sister chromatids are present in the G2 phase of a
somatic cell, such as a cell in the bone marrow of the chimpanzee?
A. 12
B. 24
C. 48
D. 96
2. Cisplatin is an anti-cancer drug that prevents tumour cells from dividing [1 mark]
by mitosis as it inhibits cell processes at stage S of interphase. How does
cisplatin prevent cancer cells from dividing?
A. It inhibits the replication of DNA.
B. It inhibits the growth of the spindle fibres.
C. It prevents the breakdown of the nuclear membrane.
D. It prevents the condensation of chromosomes.
,3. The graph shows the mitotic index in the roots of lentil plants at different [1 mark]
distances from the end of the root.
[Source: Physiologia Plantarum, Volume 105, Issue 1, January 1999, Pages 171–
178, Effect of microgravity on the cell cycle
in the lentil root F. Yu, D. Driss-Ecole, J. Rembur, V. Legué, G. Perbal Wiley Online
Library: https://onlinelibrary.wiley.
com/doi/abs/10.1034/j.1399-3054.1999.105125.x]
What can be deduced from the graph?
A. As the distance from the end of the root increases, more cells are undergoing
mitosis.
B. At 0.5 mm from the end of the root, most of the cells are in prophase.
C. There were fewer cells observed at 1.5 mm than at 0.5 mm.
D. As the distance from the end of the root increases, the percentage of cells in
interphase increases.
, 4. A tissue sample was examined under the microscope in order to [1 mark]
determine a mitotic index. The number of cells in each stage of the cell
cycle was determined and the data were entered into a table.
What is the mitotic index?
A. 0.125
B. 0.25
C. 0.75
D. 1.00
