Cambridge IGCSE Biology - 0610 - Supplement Paper 4 2011 Summer Zone 2

(a) Complete the food web in Fig. 1.1 by writing the names of the organisms in the boxes.
Write your answers in the boxes in Fig. 1.1.
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(b) Name the trophic level of the following species:

star grass ....................................................................................................................
topi ........................................................................................................................... [2]

(c) (i) State the source of energy for the food web shown in Fig. 1.1.
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(ii) State what happens to energy when it leaves an ecosystem, such as the African grassland.
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(d) Nutrients are recycled in ecosystems but energy is not recycled.
Explain why there are no more than four trophic levels in the ecosystem shown in Fig. 1.1.
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(e) Fish, such as salmon reared in fish farms, are fed on high protein food made from animals. When eating this food, these fish are feeding as secondary consumers.
Discuss the disadvantages of farming fish, such as salmon, for human food.
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Fig. 2.1 shows a person sitting in a room. A thermometer shows the temperature of the room. (a) Give three uses of energy in the body of the person in Fig. 2.1. 1. ........................................................................................................................ 2. ........................................................................................................................ 3. ........................................................................................................................ [3] (b) Name the process carried out by the person in Fig. 2.1 that releases energy. .............................................................................................................................. [2] (c) The person leaves the room and runs very fast for 200 m. When the person stops running, his breathing rate and his heart rate remain high. Explain why the person’s breathing rate and heart rate remain high after the run. .............................................................................................................................. .............................................................................................................................. .............................................................................................................................. .................................................................................................................................... [4] (d) There are changes in the skin at the beginning of the run and during the run. These changes involve the blood vessels and the sweat glands. Describe what happens to the blood vessels and sweat glands at the beginning of the run and during the run. Explain why these changes happen. .............................................................................................................................. .............................................................................................................................. .............................................................................................................................. .............................................................................................................................. .................................................................................................................................... [5]

Male and female sex hormones control the development of secondary sexual characteristics.

(a) Complete Table 3.1.  [3]

(b) Some women do not release eggs. The hormone FSH is used in fertility treatment for such women.

Name the organs in the female body responsible for the following:

(i) production of FSH [1]
(ii) release of eggs     [1]

(c) Fig. 3.1 shows changes in the concentration of FSH and three other hormones in the blood during one menstrual cycle.

(i) Describe the changes in the concentration of FSH during one menstrual cycle. [3]

(ii) Explain the role of FSH in the control of the menstrual cycle. [3]

(a) A student crossed some crimson-flowered plants with some yellow-flowered plants (cross 1). She collected the seeds and grew them. All of the plants that grew from these seeds had orange-red flowers.

Complete the genetic diagram to explain the result of cross 1.

parental phenotypes   crimson flowers   .   yellow flowers
parental genotypes   $A^C A^C$   .   $A^Y A^Y$

$$ \text{gametes} \quad &circle; \text{........................} \quad + \quad &circle; \text{........................} $$

offspring genotype   $........................$
offspring phenotype   $........................$

(b) The student then carried out three further crosses as shown in Table 4.1.

[Table_4.1]

Complete Table 4.1 by writing the genotypes of the offspring of crosses 2, 3 and 4, using the same symbols as in the genetic diagram in (a).
Write the genotypes in Table 4.1.
You may use the space below for any working.

(c) Flower colour in $M. jalapa$ is not an example of the inheritance of dominant and recessive alleles.

Explain how the results of the crosses show that these alleles for flower colour are not dominant or recessive.
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(d) Explain the difference between self-pollination and cross-pollination.
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(e) Some species of plants are self-pollinated.

Discuss the long-term effects of self-pollination on the evolution of these plants.
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(a) Outline the arguments for and against the addition of fluoride to public drinking water.
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Studies of the relationship between sugar consumption, tooth decay and fluoridation of drinking water have been carried out. Data was collected on tooth decay in 12 year-old children in Australia and Chile.

Fig. 5.1 shows changes in sugar consumption in Australia and Chile between 1970 and 2006.

Fig. 5.2 shows changes in tooth decay in the same countries over a similar time period.



(b) Describe the changes in sugar consumption and tooth decay in Australia and Chile between 1970 and 2006.

sugar consumption ........................................................................................................
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tooth decay .....................................................................................................................
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(c) The peaks for sugar consumption and tooth decay in 12 year-old children in Chile occurred at about the same time. It has been suggested that an increase in sugar consumption in children caused an increase in tooth decay.

Explain how an increase in sugar consumption may cause tooth decay.
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(d) Fig. 5.1 shows that sugar consumption in these two countries is similar. Fig. 5.2 shows the changes in tooth decay in 12 year-old children.

Suggest explanations for the similarities and differences in tooth decay in 12 year-old children in Australia and Chile.
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(a) *H. orientalis* is a dicotyledonous plant.
State three features visible in Fig. 6.1 that show it is a dicotyledonous plant.
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(b) Complete the table, using ticks (\(\checkmark\)), to show the cells that carry out photosynthesis.

\[ \begin{array}{|c|c|} \hline \text{cell} & \text{cells that carry out} \\ & \text{photosynthesis} \\ \hline \text{A} & \\ \hline \text{B} & \\ \hline \text{C} & \\ \hline \text{D} & \\ \hline \text{E} & \\ \hline \text{F} & \\ \hline \text{G} & \\ \hline \end{array} \] [2]

(c) Explain how two features of leaves, visible in sections such as that shown in Fig. 6.2, are adaptations for efficient photosynthesis.
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(d) During the period when *H. orientalis* is photosynthesising at a fast rate, substances are transported through the plant in the phloem from sources to sinks.
(i) Name two substances that are translocated from a source to a sink.
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(ii) For these substances state the source and two possible sinks.
source ..................................................................................................................
sink 1 ..................................................................................................................
sink 2 .................................................................................................................. [2]