AQA GCSE BIOLOGY Higher Tier Paper 2H 2020.

AQA GCSE BIOLOGY Higher Tier Paper 2H 2020. *junH01* IB/M/Jun20/E20 8461/2H For Examiner’s Use Question Mark 1 2 3 4 5 6 7 8 TOTAL Monday 1 June 2020 Afternoon Time allowed: 1 hour 45 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 100. • 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 BIOLOGY Higher Tier Paper 2H H 2 *02* IB/M/Jun20/8461/2H Answer all questions in the spaces provided. 0 1 This question is about the decay of milk. 0 1 . 1 Name two types of microorganism that cause decay. [2 marks] 1 2 0 1 . 2 Cows’ milk is pH 6.6. As milk decays, lipids in the milk are broken down. One of the products of the breakdown of lipids causes the pH of milk to decrease. Name the product that causes the pH to decrease. [1 mark] Do not write outside the box 3 *03* Turn over ► IB/M/Jun20/8461/2H Do not write outside the A student investigated the effect of temperature on the time taken for different types of box milk to decay. This is the method used. 1. Put cows’ milk in six test tubes. 2. Keep each test tube at a different temperature. 3. Measure the pH of the milk in each tube every day for 12 days. 4. Record the number of days taken to reach pH 5. 5. Repeat steps 1 to 4 with goats’ milk and with almond milk. 0 1 . 3 Give one way the pH can be measured. [1 mark] 0 1 . 4 Give two control variables the student should have used in this investigation. [2 marks] 1 2 Question 1 continues on the next page