Module 2 - Motisis Questions
Total Page：16
File Type：pdf, Size：1020Kb
MITOSIS QUESTIONS
1. The diagram shows four stages in mitosis. Only one pair of homologous chromosomes is shown.
X
A B C D
(a) Place stages A, B, C and D in the correct order.
...... (1)
(b) (i) Name the structures labelled X.
...... (1)
(ii) Describe the part played by the structures labelled X in this type of cell division.
......
...... (2)
(c) Each of the cells shown in the diagram contains 100 units of DNA. How many units of DNA would there be in each of the daughter cells immediately after they were formed?
...... (1) (Total 5 marks) Module 2 - Motisis Questions
2. The diagram shows some plant cells in different stages of the cell cycle.
(a) Cell T is in interphase. Describe two events which occur during interphase.
1 ......
......
2 ......
...... (2)
(b) Cells P, Q, R and S have reached different stages of mitosis. Arrange them in the correct sequence beginning with the cell representing the earliest stage
Sequence ...... (1mark)
(c) The tips of onion roots are often used to prepare slides showing cells in different stages of mitosis. As part of the procedure, the root tips are squashed and then stained.
Explain why:
(i) the tips of the roots are used;
......
......
(ii) the root tips are squashed;
......
......
(iii) the cells are stained.
......
...... (3) (Total 6 marks) Module 2 - Motisis Questions
3. (a) A microscope slide was prepared showing mitosis in a root tip from an onion bulb. Give a reason for carrying out each of the following steps:
(i) staining the tissue;
......
...... (1)
(ii) pulling the stained material apart with needles before putting on a cover slip during mounting.
......
...... (1)
(b) The graph shows the movements of chromosomes during mitosis. The curve shows the mean distance between the centromeres of the chromosomes and the corresponding pole of the spindle.
40
30
Distance/m 20
10
0 0 5 10 15 20 Time/minutes
(i) At what time did anaphase begin?
...... (1)
(ii) Explain how the graph supports your answer.
......
......
......
...... (2) (Total 5 marks) Module 2 - Motisis Questions 4. (a) A garlic root tip was examined for stages of mitosis. The root tip was cut off, stained and put on a microscope slide. A cover slip was placed on top. The root tip was squashed and then viewed through a microscope.
Give one reason for each of the following:
(i) staining the root tip;
......
...... (1)
(ii) squashing the root tip.
......
...... (1)
(b) The graph shows the amount of DNA in a cell during a cell cycle.
4x
3x Amount of DNA in cell/ arbitrary units 2x
x
0 P Q R Time
(i) Name the stage occurring between time P and time Q. Give the reason for your answer.
Stage ......
Reason ......
...... (2)
(ii) Explain the decrease in the amount of DNA present at time R.
......
......
...... (1) (Total 5 marks) Module 2 - Motisis Questions
5. Black bean aphids are small insects which feed on broad bean plants. The diagram shows stages in the life cycle of the black bean aphid. The adult females undergo one of two alternative life cycles depending on the time of year.
The boxes show the number of chromosomes present in a single cell from the particular stage indicated.
Growth Juvenile
Asexual reproduction in spring and summer
Adult female 8
Nymph
Eggs Sexual reproduction in autumn and winter
Fertilisation
Sperm Adult male
8
(a) (i) Complete the boxes to show the number of chromosomes present in a single cell at that stage of the life cycle. (1)
(ii) Label one of the arrows with the letter M to show where meiosis takes place. (1)
(b) Use your knowledge of cell division to explain why a juvenile aphid is genetically identical to its parent.
......
......
...... (2)
(c) Hoverfly larvae and lacewing larvae are both predators of black bean aphids. An investigation was carried out to see which of these predators would be the better biological control of black bean aphids. The graphs show the results of this investigation. Module 2 - Motisis Questions Field A Field B
Black bean 750 aphids 750 Black bean aphids Number of Number of 500 500 individuals/ individuals/ 2 2 per m Lacewing per m Hoverfly 250 larvae 250 larvae
0 0 0 5 10 15 0 5 10 15 Time/days Time/days
It was concluded that hoverfly larvae are better for biological control of black bean aphids. Explain the evidence from the graphs that
(i) supports this conclusion
......
......
......
......
(ii) conflicts with this conclusion.
......
......
......
......
......
......
...... (5)
(d) Describe and explain the ways in which weeds and insect pests reduce crop yields
......
......
......
......
...... (6) (Total 15 marks)