Cambridge IGCSE Biology - 0610 - Supplement Paper 4 2016 Summer Zone 3

(a) Fig. 1.1 shows the human gas exchange system. The functions of the parts of the gas exchange system are given in Table 1.1.

Complete Table 1.1. One row has been done for you.
[Table_1]

(b) The gas exchange system contains cartilage.

Describe the function of cartilage in the gas exchange system.
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(c) Soon after starting physical activity the concentration of carbon dioxide in the blood increases.

(i) Name the process inside cells that produces carbon dioxide.
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(ii) State the effect on breathing of an increase in carbon dioxide concentration in the blood.
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(iii) Explain how this effect on breathing is coordinated.
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(a) (i) State the name of the tissue X.
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(ii) State the name of the nerve that transmits impulses from the eye to the brain.
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(iii) State what happens to rays of light as they enter the cornea and the lens.
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(iv) Describe the role of rod cells.
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(b) A plant, Arabidopsis thaliana, was placed on its side in the dark. Fig. 2.2 is a series of drawings made of the plant, over seven days, as it responded to a change in its surroundings.
(i) State the stimulus to which the plant responded.
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(ii) Name the growth response shown by the plant.
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(iii) Explain the advantage to plants of the growth response shown in Fig. 2.2.
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(iv) Auxins control the growth responses of seedlings.
Explain how auxins control the growth response of A. thaliana, shown in Fig. 2.2.
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(a) Sex in cats is determined in the same way as in humans. Complete the diagram below to show how sex is determined in cats.
male cat × female cat

offspring ratio............................................................................................................................

(b) A scientist investigated the inheritance of fur colour in cats. The gene for coat colour is located on the X chromosome. The gene has two alleles:
• B black
• b orange.
The X chromosome with the allele for black is represented by $X^B$. The X chromosome with the allele for orange is $X^b$.
A female cat can be a mixture of these colours, described as calico. Fig. 3.1 shows the inheritance of this condition in a family of cats.

(i) State the genotypes of cats 1, 4, and 5 in Fig. 3.1.
cat 1 ..............................................................................................................
cat 4 ..............................................................................................................
cat 5 ..............................................................................................................
(ii) Coat colour in cats is an example of discontinuous variation. Explain why coat colour is an example of discontinuous variation.
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A student investigated the diffusion of substances through Visking tubing, an artificial membrane which has some of the properties of cell membranes.

The student made a bag of Visking tubing as shown in Fig. 4.1.

The student added some iodine solution to the water in the test-tube.

After 30 minutes at room temperature, the contents of the Visking bag were stained blue-black, but the water outside remained a yellow colour. 

(i) Explain these results. [4] 

(ii) State three factors that influence the movement of molecules through membranes. [3]

Fig. 5.1 shows an area of forest where some of the trees have been cut down.

(a) Explain the reasons why forests may be cut down as shown in Fig. 5.1.
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(b) The loss of forests from parts of the world is assessed by satellite imagery. Table 5.1 shows data on the forests in Indonesia and Malaysia, two countries in South-East Asia which have large areas of forest.
[Table_1]
(i) Calculate the percentage loss of natural forest in Indonesia between 1990 and 2010. Show your working and express your answer to the nearest whole number.
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(ii) Use the data in Table 5.1 to compare the loss of natural forest in Indonesia with the loss of natural forest in Malaysia.
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(iii) Many hectares of natural forest have been cleared in countries such as Malaysia and Indonesia for oil palm plantations. Both countries have also replanted forests to grow timber and other forest products.
Suggest why replanted forests and plantations are less useful for conservation than natural forest.
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(c) Discuss the effects of deforestation on areas of land.
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Fig. 6.1 shows the alimentary canals of two mammals, an insect-eating bat, which is a carnivore, and a rabbit, which is a herbivore.



(a) Name the organs labelled V and W.

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W ..........................................................................................................................
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(b) Explain the role of mechanical digestion.

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Scientists investigated digestion in different species of mammal. The mammals that they studied ranged in size from an elephant shrew, *Elephantulus edwardii*, with a mass of 50 g to an ox, *Bos taurus*, with a mass of 220 kg.

The scientists added indigestible particles to the animals’ food and timed how long the particles stayed in the digestive system.

The results for 24 different mammal species are shown in Fig. 6.2.


(c) The scientists concluded that food stays longer in the digestive systems of larger mammals compared with smaller mammals.

Discuss the evidence from Fig. 6.2 for and against the statement that food stays longer in the digestive systems of larger mammals.

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