2024 AQA GCSE BIOLOGY 8461/2H Paper 2. Question Paper with Merged Marking Scheme. June 2024 APPROVED

2024 AQA GCSE BIOLOGY 8461/2H Paper 2. Question Paper with Merged Marking Scheme. June 2024 APPROVED Candidate number I declare this is my own work. GCSE BIOLOGY Higher Tier Paper 2H H Friday 7 June 2024 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. For Examiner’s Use Question Mark 1 2 3 4 5 6 7 8 9 TOTAL *JUN2484612H01* IB/H/Jun24/E14 8461/2H 2 Answer all questions in the spaces provided. 0 1 Evolution of new species occurs by mutation and natural selection. 0 1 . 1 What is a mutation? [1 mark] 0 1 . 2 Describe the process of natural selection. [3 marks] 0 1 . 3 Which scientists suggested the theory of evolution by natural selection? [1 mark] Tick () one box. Alexander Fleming and Carl Woese Alfred Wallace and Alexander Fleming Alfred Wallace and Charles Darwin Charles Darwin and Carl Woese Do not write outside the box 002* IB/H/Jun24/8461/2H 3 0 1 . 4 The hoverfly and the wasp are insects with bright yellow and black markings. Figure 1 shows a hoverfly and a wasp. Figure 1 The wasp has a sting to defend itself against predators. The hoverfly does not have a sting. Hoverflies and wasps live in the same habitat. Explain how having yellow and black markings helps the hoverfly survive. [3 marks] Turn over for the next question Turn over ► *03* IB/H/Jun24/8461/2H Do not write outside the box 8 4 Peat bogs are estimated to contain twice as much carbon as all the world’s forests. 0 2 Figure 2 shows a section through part of a peat bog. Figure 2 Layer A contains a lot of air. Layer B: • contains the dead remains of plants • has a low pH • contains very little oxygen • contains carbon dioxide and methane. *04* IB/H/Jun24/8461/2H Do not write outside the box 5 0 2 . 1 Explain why most of the dead remains of plants in layer B do not decay. [3 marks] 0 2 . 2 The peat bog in Figure 2 is a stable community. The moss produces biomass at a rate of 340 g/m2/year. What is the approximate biomass of the moss that becomes biomass in primary consumers? [1 mark] Tick () one box. 0.34 g/m2/year 3.4 g/m2/year 34 g/m2/year 340 g/m2/year Question 2 continues on the next page Do not write outside the box Turn over ► *05* IB/H/Jun24/8461/2H 6 The sundew plant shown in Figure 2 on page 4 has leaves with sticky hairs that trap and digest insects. Digestion of the insects releases phosphates and simple compounds of nitrogen that are used by the sundew plant. 0 2 . 3 What substance can the sundew plant make using the phosphates? [1 mark] Tick () one box. Cellulose DNA Glycerol Starch 0 2 . 4 What substance can the sundew plant make using the nitrogen? [1 mark] Tick () one box. Fatty acid Glucose Lactic acid Protein Do not write outside the box *06* IB/H/Jun24/8461/2H 7 0 2 . 5 Humans have destroyed large areas of peat bog to collect peat. The peat provides fuel and provides compost for gardeners to use. The peat comes from layer B in Figure 2 on page 4. Layer B: • contains the dead remains of plants • has a low pH • contains very little oxygen • contains carbon dioxide and methane. Figure 3 shows the removal of peat from a peat bog. Figure 3 Explain how the destruction of peat bogs and the use of peat affects the temperature of the Earth’s atmosphere. [4 marks] Turn over ► *07* IB/H/Jun24/8461/2H Do not write outside the box 10 8 Turn over for the next question DO NOT WRITE ON THIS PAGE ANSWER IN THE SPACES PROVIDED *08* IB/H/Jun24/8461/2H Do not write outside the box 9 Frogs are animals that lay their eggs in water. The eggs hatch as tadpoles. 0 3 Students investigated the number of tadpoles in a pond for 8 weeks. This is the method used. 1. Collect 10 dm3 of pond water in a bucket. 2. Count the number of tadpoles collected. 3. Put the tadpoles back into the pond. 4. Repeat steps 1 to 3 another three times in different parts of the pond. 5. Repeat steps 1 to 4 at intervals for 8 weeks. 0 3 . 1 Suggest one improvement to the method. [1 mark] Question 3 continues on the next page Turn over ► *09* IB/H/Jun24/8461/2H Do not write outside the box 10 Table 1 shows the results. Table 1 Sample Number of tadpoles in each sample number 0 weeks 1 week 2 weeks 3 weeks 5 weeks 8 weeks 1 11 17 8 9 5 0 0 5 7 3 4 11 14 16 X 4 4 Totals 12 0 3 . 2 Value X is the number of tadpoles in sample 4, at 3 weeks. Calculate value X. [1 mark] Value X = Do not write outside the box *10* IB/H/Jun24/8461/2H 11 0 3 . 3 Complete Figure 4 to show how the total number of tadpoles changed over the 8 weeks. [4 marks] You should: • label the x-axis • use a suitable scale for the x-axis • plot the data for the total numbers of tadpoles from Table 1 • draw a line of best fit. Figure 4 0 3 . 4 After 0 weeks, no more tadpoles hatched in the pond. Calculate the percentage of the tadpoles that would still be found in the pond at 4 weeks compared with 0 weeks. Use information from Figure 4. [3 marks] Percentage of tadpoles found at 4 weeks = % Do not write outside the box Turn over ► *11* IB/H/Jun24/8461/2H 12 0 3 . 5 After 4 weeks many of the tadpoles had died. Suggest two reasons why the tadpoles died.