Biology 0610/33 October/November 2025: question paper and mark scheme

Question

(a) Enzymes are involved in all metabolic reactions. The box on the left contains the word ‘Enzymes’. The boxes on the right contain some sentence endings. Draw lines to make three correct sentences about enzymes. all have an optimum temperature of 20 °C. are biological catalysts. are carbohydrates. Enzymes are changed by reactions. are found in plant cells. increase the rate of reactions. [3] (b) State the name of the substrate that protease enzymes act on and the name of the products formed. substrate …… products …… [2] * 0000800000003 * DFD 3 (c) Fig. 1.1 shows the activity of a protease enzyme at different pH values. 9 8 7 6 enzyme 5 activity / arbitrary units 4 3 2 1 0 7 8 9 10 11 12 pH Fig. 1.1 Describe the activity of the enzyme shown in Fig. 1.1. …… [3] * 0000800000004 * DFD 4 (d) (i) Circle the name of an organ that secretes protease. gall bladder pancreas rectum salivary gland [1] (ii) Circle the name of an organ where protease acts. large intestine mouth oesophagus small intestine [1] (e) A different protease enzyme is found in the stomach. The stomach contains hydrochloric acid. Describe two functions of hydrochloric acid in the stomach. 1 …… 2 …… [2] (f) The stomach is also involved in physical digestion. Describe the function of the stomach in physical digestion. …… [1] [Total: 13] * 0000800000005 * DFD 5 * 0000800000006 * DFD 6

Question

(a) Fig. 2.1 shows a diagram of a cell found in the lungs of a human. D A C B Fig. 2.1 (i) State the names of structures A and B in Fig. 2.1. A …… B …… [2] (ii) State the functions of structures C and D in Fig. 2.1. C …… D …… [2] (b) (i) State the name of the structures that form the gas exchange surface in the lungs. …… [1] (ii) State the name of the gas which is excreted by the lungs. …… [1] * 0000800000007 * DFD 7 (c) (i) Urea is excreted by the body. Table 2.1 shows parts of the body that urea passes through during excretion. The structures are not in the correct order. Table 2.1 A bladder B blood C kidney D ureter E urethra Identify the order of parts of the body that urea passes through during excretion. Write the letters from Table 2.1 in the correct order, in the boxes provided. One has been done for you. B [2] (ii) State the names of two other substances that are excreted by the kidneys. …… [2] [Total: 10] * 0000800000008 * DFD 8

Question

(a) Complete the sentences about transpiration. Transpiration is the loss of water vapour from leaves. Water evaporates from the surfaces of the …… cells into the …… spaces. Water vapour moves out of the leaves through the …… by the process of …… . [4] (b) A student investigated the effect of temperature on the rate of transpiration in a leafy shoot, using the apparatus shown in Fig. 3.1. leafy shoot reservoir ruler water capillary air tube bubble reservoir Fig. 3.1 The rate of transpiration was estimated by measuring the distance moved by the air bubble every 3 minutes. This was repeated at six different temperatures. The results are shown in Table 3.1. Table 3.1 temperature distance moved by the air rate of transpiration / °C bubble in 3 minutes / mm / mm per minute 20 18 6 25 45 30 54 18 35 66 22 40 69 23 45 69 23 * 0000800000009 * DFD 9 (i) Using the data in Table 3.1, calculate the rate of transpiration at 25 °C. …… mm per minute [1] (ii) The list shows six conclusions. Tick () three conclusions for the data shown in Table 3.1. As temperature increases, the distance moved by the air bubble decreases. As temperature increases, the rate of transpiration decreases. As temperature increases, the rate of transpiration increases and then remains constant. From 20 °C to 30 °C, the rate of transpiration triples. From 20 °C to 45 °C, the rate of transpiration increases by 17 mm per minute. The maximum rate of transpiration was 22 mm per minute. [3] [Total: 8] * 0000800000010 * DFD 10

Question

(a) Describe what is meant by the term fertilisation. …… [2] (b) Fig. 4.1 is a diagram of a sperm cell. H G Fig. 4.1 (i) Complete Table 4.1 by stating the names and functions of the parts labelled G and H in Fig. 4.1. Table 4.1 letter in name function Fig. 4.1 G H [4] (ii) State the name of the organ that produces sperm. …… [1] (iii) State the sex chromosomes in a male human. …… [1] (iv) State the probability that a human baby will be a boy. …… [1] [Total: 9] * 0000800000011 * DFD 11

Question

Humans have increased food production over time. (a) Fig. 5.1 shows how rice production increased from 1960 to 2010 in one country. 500 450 400 350 300 rice production / million tonnes 250 200 150 100 50 0 1960 1965 1970 1975 1980 1985 1990 1995 2000 2005 2010 year Fig. 5.1 (i) Using the information in Fig. 5.1, state the five‑year period which shows the greatest increase in rice production. from …… to …… [1] (ii) Using the information in Fig. 5.1, calculate the percentage increase in rice production from 1960 to 1990. Give your answer to the nearest whole number. Space for working. ……% [3] * 0000800000012 * DFD 12 (b) State three methods that humans use to increase crop plant production. 1 …… 2 …… 3 …… [3] (c) Fig. 5.2 is a photograph of intensive farming of sheep. Fig. 5.2 (i) Describe the advantages of intensive farming of livestock. …… [3] * 0000800000013 * DFD 13 (ii) One of the disadvantages of intensive farming of livestock is that untreated sewage from the animals can enter aquatic ecosystems. State two effects of untreated sewage on aquatic ecosystems. 1 …… 2 …… [2] [Total: 12] * 0000800000014 * DFD 14

Question

(a) Yoghurt can be made by adding the bacteria Lactobacillus bulgaricus to milk. (i) State the genus name for these bacteria. …… [1] (ii) State two reasons why bacteria are useful in biotechnology processes such as making yoghurt. 1 …… 2 …… [2] (b) Fig. 6.1 shows the nutritional information for 100 g of a type of yoghurt. carbohydrate 4.7 g fat 3.3 g fibre 0.0 g protein 3.5 g Fig. 6.1 (i) A person wants to eat 45 g of protein. The person ate 200 g of yoghurt. Using the information in Fig. 6.1, calculate the mass of protein the person needs to eat, in addition to the yoghurt, to reach 45 g of protein. mass of protein in 200 g of yoghurt …… g mass of additional protein the person needs to eat …… g [2] (ii) State the importance of fats in the diet. …… [1] * 0000800000015 * DFD 15 (iii) Yoghurt does not contain fibre. State one principal dietary source of fibre. …… [1] (c) Yeast is another microorganism that is used in biotechnology. Anaerobic respiration in yeast is used in bread‑making. (i) State the word equation for anaerobic respiration in yeast. …… [2] (ii) Describe the role of anaerobic respiration in yeast during bread‑making. …… [1] (iii) State one other use of yeast in biotechnology. …… [1] [Total: 11] * 0000800000016 * DFD 16

Question

(a) Fig. 7.1 shows a plant in a light‑proof box. light-proof box plant shoot plant pot plant roots Fig. 7.1 The plant was placed on its side in the light‑proof box. (i) Complete Fig. 7.2 by drawing the expected appearance of the shoot and roots of the plant after a week. light-proof box plant pot plant Fig. 7.2 [2] (ii) State the name of the tropic response shown by the plant in Fig. 7.2. …… [1] * 0000800000017 * DFD 17 (b) State the function of a root hair cell, and describe how it is adapted for its function. function …… adaptation …… [4] [Total: 7] * 0000800000018 * DFD 18

Question

(a) Fig. 8.1 is a photograph of a human eye. S T Fig. 8.1 (i) State the name of structure S in Fig. 8.1. …… [1] (ii) State the function of structure T in Fig. 8.1. …… [1] (b) Eyelash length is a human characteristic controlled by a single gene. People can have either short eyelashes or long eyelashes. (i) Describe what is meant by the term gene. …… [2] (ii) Suggest one reason why eyelash length in humans could be an example of discontinuous variation. …… [1] * 0000800000019 * DFD 19 (c) The allele for long eyelashes is represented by the letter E. The allele for short eyelashes is represented by the letter e. • The genotype of a male was ee. • The genotype of a female was Ee. (i) Table 8.1 shows some terms used to describe these genotypes. Place ticks () in the boxes in Table 8.1 to show the correct descriptions for these genotypes. Table 8.1 homozygous homozygous genotype heterozygous dominant recessive ee Ee [2] (ii) A male with the genotype ee had a child with a female with the genotype Ee. Complete the Punnett square to show the: • gametes of the male and the female • possible genotypes of the offspring from this cross • ratio of long eyelashes to short eyelashes in the offspring from this cross. male female The ratio of long eyelashes to short eyelashes in the offspring is …… [3] [Total: 10] * 0000800000020 * DFD 20