AQA GCSE COMBINED SCIENCE: TRILOGY 8464/B/2H Higher Tier Biology Paper 2H Question Paper + Mark scheme [MERGED] June 2022 *jun228464b2h01* IB/M/Jun22/E10 8464/B/2H For Examiner’s Use Question Mark 1 2 3

AQA GCSE COMBINED SCIENCE: TRILOGY 8464/B/2H Higher Tier Biology Paper 2H Question Paper + Mark scheme [MERGED] June 2022 *junb2h01* IB/M/Jun22/E10 8464/B/2H For Examiner’s Use Question Mark 1 2 3 4 5 6 TOTAL Time allowed: 1 hour 15 minutes Materials For this paper you must have: • a ruler • a scientific calculator. Instructions • Use black ink or black ball-point pen. • Pencil should only be used for drawing. • Fill in the boxes at the top of this page. • Answer all questions in the spaces provided. • If you need extra space for your answer(s), use the lined pages at the end of this book. Write the question number against your answer(s). • Do all rough work in this book. Cross through any work you do not want to be marked. • In all calculations, show clearly how you work out your answer. Information • The maximum mark for this paper is 70. • The marks for questions are shown in brackets. • You are expected to use a calculator where appropriate. • You are reminded of the need for good English and clear presentation in your answers. Please write clearly in block capitals. Centre number Candidate number Surname Forename(s) Candidate signature I declare this is my own work. GCSE COMBINED SCIENCE: TRILOGY Higher Tier Biology Paper 2H H 2 *02* IB/M/Jun22/8464/B/2H 0 1 This question is about the cycling of water and carbon in ecosystems. 0 1 . 1 Which reaction produces water? [1 mark] Tick () one box. Aerobic respiration Anaerobic respiration Photosynthesis The water cycle provides water for plants and animals on land before the water goes into lakes and seas. Figure 1 represents the water cycle. Figure 1 Do not write outside the box 3 *03* Turn over ► IB/M/Jun22/8464/B/2H Do not write outside the 0 1 box . 2 Name the processes 1 to 5 shown on Figure 1. [5 marks] 1 2 3 4 5 0 1 . 3 In 2007 the population of the world was A study found that 4.5% of the population had severe water shortage. Calculate how many people had severe water shortage. Give your answer in standard form. [3 marks] Number of people (in standard form) = Question 1 continues on the next page 4 *04* IB/M/Jun22/8464/B/2H Do not write outside the box 0 1 . 4 Why do more people have severe water shortage now than in 2007? [2 marks] Tick () two boxes. Climate change has increased the area of deserts. Each person drinks less water. More water is used to grow crops. Sea levels have risen because the ice caps are melting. Some countries have built de-salting factories for seawater. Leaves on a tree contain carbon compounds. In autumn the leaves fall to the ground. 0 1 . 5 Microorganisms in the soil recycle carbon from the leaves so that the carbon is used for new plant growth. Explain how. [4 marks] 5 *05* Turn over ► IB/M/Jun22/8464/B/2H Do not write outside the box 16 0 1 . 6 What is one benefit of fallen leaves for living plants? [1 mark] Tick () one box. Energy is released for living plants. Insect pests in the soil are killed. Nitrates are released into the soil. Oxygen is supplied to root cells. Turn over for the next question 6 *06* IB/M/Jun22/8464/B/2H Do not write outside the box 6 0 2 Water pollution is a problem for humans and wildlife. Explain how human activities are polluting rivers, lakes and seas. [6 marks] 7 *07* Turn over ► IB/M/Jun22/8464/B/2H Do not write outside the box 7 0 3 On a school field: • one area of the soil was usually wet • another area of the soil was usually dry. Students investigated the effect of water in the soil on the number of buttercup plants growing in each area. 0 3 . 1 Water is an abiotic factor. Name one biotic factor which may affect the number of buttercups growing on the field. [1 mark] 0 3 . 2 Describe a method to investigate if the amount of water in the soil affects the number of buttercups in the field. [6 marks] 8 *08* IB/M/Jun22/8464/B/2H Do not write outside the There are no questions printed on this page box DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED 9 *09* Turn over ► IB/M/Jun22/8464/B/2H Do not write outside the 0 4 Scientists investigated the effect of soil nitrate ion concentration on the yield of corn. box This is the method used. 1. Corn plants were grown in a large box of soil. 2. The soil nitrate ion concentration in the box was kept at 0 parts per million (ppm). 3. All the corn from each plant in the box was removed and weighed. 4. The mean mass of corn per plant was calculated. 5. Steps 1 to 4 were repeated for boxes containing soil with different concentrations of nitrate ions. Figure 2 shows the corn plants in the box with a 20 ppm soil nitrate ion concentration. Figure 2 0 4 . 1 Give two variables the scientists should have controlled in this investigation. [2 marks] 1 2 10 *10* IB/M/Jun22/8464/B/2H Do not write outside the The scientists carried out a valid investigation. box Table 1 shows the scientists’ results. Table 1 Soil nitrate ion concentration in ppm Mean mass of corn per plant in grams 0 122 10 190 20 256 30 268 40 240 50 184 11 *11* Turn over ► IB/M/Jun22/8464/B/2H Do not write outside the box 0 4 . 2 Complete Figure 3. You should: • label the y-axis • use a suitable scale for the y-axis • plot the data from Table 1 • draw a line of best fit. [4 marks] Figure 3 12 *12* IB/M/Jun22/8464/B/2H Do not write outside the Table 1 box is repeated below. Table 1 Soil nitrate ion concentration in ppm Mean mass of corn per plant in grams 0 122 10 190 20 256 30 268 40 240 50 184 0 4 . 3 Describe the relationship between soil nitrate ion concentration and the mean mass of corn per plant. Use data from Table 1 in your answer. [2 marks] 13 *13* Turn over ► IB/M/Jun22/8464/B/2H Do not write outside the box 12 0 4 . 4 Farmers add nitrate fertiliser to fields where they grow corn. Nitrate fertilisers are expensive. Evaluate the economic and environmental implications of adding fertiliser to soil in nitrate ion concentrations ranging from 0 to 50 ppm