Official June 2026 AQA AS BIOLOGY 7401/2 Paper 2 Merged Question Paper + Mark Scheme (46pages)

Answer all questions in the spaces provided. box 0 1 . 1 Water has a high heat capacity and a large latent heat of vaporisation. Describe the importance of each of these properties to living organisms. [2 marks] High heat capacity Large latent heat of vaporisation 0 1 . 2 Figure 1 shows that water loss from a porous pot can cause the upward movement of water. Figure 1 3 *03* Turn over ► IB/M/Jun24/7401/2 Do not write outside the Biologists have concluded that the experiment in Figure 1 supports the box cohesion–tension theory of water transport in the xylem. Explain how this conclusion is supported by the experiment in Figure 1. [3 marks] 0 1 . 3 An air bubble was introduced into the glass tubing in Figure 1. The air bubble moved a distance (d) of 1.5 cm in 120 minutes. The radius of the lumen (hole) of the glass tubing was 0.6 cm Use this information and the formula πr2 d to calculate the rate of water movement in the glass tubing in cm3 hour–1 . Use π = 3.14 in your calculation. [1 mark] Answer cm3 hour–1 6 4 *04* IB/M/Jun24/7401/2 Do not write outside the 0 2 box . 1 Figure 2 shows an image of a red blood cell at a magnification of × 5500 Figure 2 Calculate the actual diameter in μm of the red blood cell between points P and Q. Show your working. [2 marks] Answer μm 5 *05* Turn over ► IB/M/Jun24/7401/2 Do not write outside the 0 2 box . 2 A haemocytometer is a special microscope slide that can be used to determine the mean number of red blood cells in 0.004 mm3 of blood. • A researcher prepared a 10–3 dilution of a sample of blood from an adult. • Using a haemocytometer, the researcher determined that the mean number of red blood cells in 0.004 mm3 of the diluted blood sample was 21 The volume of blood in the body of the adult was 4.8 dm3 Calculate the total number of red blood cells in the body of this adult. Show your working. [2 marks]