Cambridge IGCSE Biology - 0610 - Supplement Paper 4 2010 Summer Zone 1

(a) Define the term sensitivity.
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................
.............................................................................................................................. [2]

Fig. 1.1 shows a horizontal section through the eye.

(b) (i) Name structures A to D.
A
..............................................................................................................................
B
..............................................................................................................................
C
..............................................................................................................................
D
.............................................................................................................................. [4]
(ii) State the functions of structures B and E.
B
..............................................................................................................................
E
.............................................................................................................................. [2]

The retina contains light-sensitive cells known as rods and cones. The distribution of rods in the retina from point X to point Y, as shown on Fig. 1.1, was investigated.

Fig. 1.2 shows the distribution of rods in the retina from point X to point Y.

(c) (i) G and H, as shown on Fig. 1.2, are parts of the retina.
Name G and H.
G
..............................................................................................................................
H
.............................................................................................................................. [2]
(ii) Describe the function of the rods.
..............................................................................................................................
..............................................................................................................................
..............................................................................................................................
.............................................................................................................................. [2]
(iii) Draw a line on Fig. 1.2 to show the distribution of cones in the retina. [2]

A student measured the uptake and release of carbon dioxide from a plant during 24 hours. It was a very bright, sunny day between sunrise and sunset.
Fig. 2.1 shows the student’s results.



(a) (i) Use the information in Fig. 2.1 to state the time that sunrise occurred.
............................................................................................................................................................. [1]
(ii) Using Fig. 2.1, state the times when there is no uptake or release of carbon dioxide.
1. ......................................................................................................................................................
2. ...................................................................................................................................................... [1]
(iii) State why plants release carbon dioxide at night.
..........................................................................................................................................................
.......................................................................................................................................................... [1]
(iv) Explain why it is important for plants that carbon dioxide uptake during the day is greater than carbon dioxide released at night.
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
.......................................................................................................................................................... [2]

The yields of tomatoes grown in open fields in India are very low compared with yields of tomatoes grown in glasshouses in Europe.
In a study, scientists in India grew tomato plants in glasshouses and in open fields nearby. The growth of the plants and the yields of tomatoes were recorded.
The results are shown in Table 2.1.

[Table_1]

(b) (i) The mean fresh mass of tomatoes grown in glasshouses was greater than the mean fresh mass of tomatoes grown in open fields. Calculate the difference in mean fresh mass as a percentage of the mean fresh mass of tomatoes grown in open fields.
Show your working.
Answer = ........................................................... % [2]
(ii) Suggest how an increase in the height of the plants and the number of leaves on each plant affects the yield of tomatoes.
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
.......................................................................................................................................................... [3]
(c) The scientists made sure that the only differences between the two groups of plants were the result of the protection provided by the glasshouses. Suggest the factors that the scientists should have kept the same for the two groups of plants in this investigation.
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
.......................................................................................................................................................... [3]
(d) The growth and final yields of crops grown in open fields are often limited by environmental factors. Describe how these factors are controlled in commercial glasshouses to give high yields of crops such as tomatoes.
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
..........................................................................................................................................................
.......................................................................................................................................................... [4]

Fig. 3.1 shows a human egg cell and a human sperm cell.



(a) (i) What is the name given to the release of eggs from the ovary?
.................................................................................................................................. [1]
(ii) Sperm cells and egg cells are haploid. State the meaning of the term haploid.
.................................................................................................................................. [1]

(b) Complete the table to compare egg cells with sperm cells.

[Table_1]

feature | egg cells | sperm cells
site of production | |
relative size | |
numbers produced | |
mobility | |

[4]

(c) Three hormones that control the menstrual cycle are:
• follicle stimulating hormone (FSH)
• luteinising hormone (LH)
• oestrogen.

(i) Name the site of production and release of oestrogen.
.................................................................................................................................. [1]
(ii) Describe the role of oestrogen in controlling the menstrual cycle.
..................................................................................................................................
..................................................................................................................................
..................................................................................................................................
..................................................................................................................................
[2]

(d) Artificial insemination is sometimes used as a treatment for female infertility.
Outline how artificial insemination is carried out in humans.
..................................................................................................................................
..................................................................................................................................
..................................................................................................................................
..................................................................................................................................
[2]

(a) (i) State one cause of acid rain other than that shown in Fig. 4.1.
..................................................................................................................................................................... [1]
(ii) Describe two effects of acid rain on forest ecosystems.
1. ..................................................................................................................................................................
........................................................................................................................................................................
2. .................................................................................................................................................................
........................................................................................................................................................................ [2]
(b) Describe two different ways to reduce pollution so that there is less acid rain.
1. ..................................................................................................................................................................
........................................................................................................................................................................
2. .................................................................................................................................................................
........................................................................................................................................................................ [2]

(c) State one feature of molluscs that is not a feature of crustaceans.
..................................................................................................................................................................... [1]
(d) Using the information in Fig. 4.2,
(i) name an animal that could be found in a lake with a pH of 4.0;
..................................................................................................................................................................... [1]
(ii) name the animals that are most sensitive to a decrease in pH;
..................................................................................................................................................................... [1]
(iii) suggest why some animals cannot tolerate living in water of pH as low as 4.0.
................................................................................................................................................................
.....................................................................................................................................................................
..................................................................................................................................................................... [2]

(a) (i) Explain why the milk must be cooled before the bacteria are added.

..................................................................................................................................................................................
..................................................................................................................................................................................
.................................................................................................................................................................................. [2]

(ii) Explain why the pH decreases only after the oxygen in the milk has been used up.

..................................................................................................................................................................................
..................................................................................................................................................................................
.................................................................................................................................................................................. [2]

(iii) Suggest one type of food additive that could be added to yoghurt.

.................................................................................................................................................................................. [1]

(b) Using your knowledge of population growth and the factors that affect it, describe and explain the growth of $S.\ thermophilus$, as shown in Fig. 5.2.

..................................................................................................................................................................................
..................................................................................................................................................................................
..................................................................................................................................................................................
..................................................................................................................................................................................
..................................................................................................................................................................................
..................................................................................................................................................................................
..................................................................................................................................................................................
.................................................................................................................................................................................. [5]

(c) Suggest why the numbers of $L.\ bulgaricus$ do not start to increase until after the increase in the numbers of $S.\ thermophilus$.

..................................................................................................................................................................................
..................................................................................................................................................................................
..................................................................................................................................................................................
.................................................................................................................................................................................. [2]

(a) (i) State two types of natural disaster that occur suddenly and may lead to severe food shortages.
1.
..........................................................................................................................................
2.
.......................................................................................................................................... [2]

(a) (ii) State one type of natural disaster that may take several years to develop.
.................................................................................................................................................................................... [1]

(b) Use the information in Fig. 6.1 and Fig. 6.2 to describe the changes in food shortages between 1981 and 2007.
.............................................................................................................................................................................................................................
.............................................................................................................................................................................................................................
.............................................................................................................................................................................................................................
.............................................................................................................................................................................................................................
............................................................................................................................................................................................................................. [5]

(c) Explain how the increase in the human population may contribute to severe food shortages.
.............................................................................................................................................................................................................................
.............................................................................................................................................................................................................................
............................................................................................................................................................................................................................. [3]

(d) Use a named example to outline how artificial selection is used to improve the quantity or quality of food.
.............................................................................................................................................................................................................................
.............................................................................................................................................................................................................................
.............................................................................................................................................................................................................................
............................................................................................................................................................................................................................. [4]

(e) Define the term genetic engineering.
.............................................................................................................................................................................................................................
.................................................................................................................................................................................. [1]