BIO EVOLUTIONA-Biology Paper 1

BIO EVOLUTIONA-Biology Paper 1 Tuesday 12 May 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 1H H 2 *02* IB/M/Jun20/8461/1H Answer all questions in the spaces provided. 0 1 This question is about photosynthesis. 0 1 . 1 Complete the word equation for photosynthesis. [2 marks] + → + oxygen 0 1 . 2 Describe how energy for the photosynthesis reaction is gained by plants. [2 marks] Students investigated the effect of temperature on the rate of photosynthesis. The students shone light from a lamp onto pondweed and measured the volume of oxygen produced per hour. Table 1 shows the results. Table 1 Temperature in °C Rate of photosynthesis in cm3 /hour Test 1 Test 2 Test 3 Mean 20 18.5 19.3 19.5 X 25 32.6 34.1 32.9 33.2 30 41.9 45.2 44.9 44.0 35 38.6 39.8 44.0 40.8 40 23.1 20.5 22.4 22.0 45 1.9 14.2 2.2 2.1 Do not write outside the box 3 *03* Turn over ► IB/M/Jun20/8461/1H Do not write outside the box 0 1 . 3 Calculate mean value X. [2 marks] X = cm3 /hour The students identified one anomalous result in Table 1. 0 1 . 4 Draw a ring around the anomalous result in Table 1. [1 mark] 0 1 . 5 Suggest one possible cause of the anomalous result. [1 mark] 0 1 . 6 How did the students deal with the anomalous result? [1 mark] 0 1 . 7 Give one factor the students should have kept constant in this investigation. [1 mark] 4 *04* IB/M/Jun20/8461/1H Do not write outside the box Table 1 is repeated below. Table 1 Temperature in °C Rate of photosynthesis in cm3 /hour Test 1 Test 2 Test 3 Mean 20 18.5 19.3 19.5 X 25 32.6 34.1 32.9 33.2 30 41.9 45.2 44.9 44.0 35 38.6 39.8 44.0 40.8 40 23.1 20.5 22.4 22.0 45 1.9 14.2 2.2 2.1 0 1 . 8 Why did the rate of photosynthesis decrease from 35 °C to 45 °C? [1 mark] 5 *05* Turn over ► IB/M/Jun20/8461/1H Do not write outside the box 16 0 1 . 9 Complete Figure 1 using data from Table 1. You should: • label the y-axis • use a suitable scale for the y-axis • plot the mean data from Table 1 for temperatures from 25 °C to 45 °C • draw a line of best fit. [5 marks] Figure 1 Turn over for the next question 6 *06* IB/M/Jun20/8461/1H Do not write outside the 0 2 Diffusion is an important process in animals and plants. box 0 2 . 1 What is meant by the term diffusion? [2 marks] 7 *07* Turn over ► IB/M/Jun20/8461/1H Do not write outside the box 0 2 . 2 Figure 2 shows part of a leaf. Figure 2 Molecules of carbon dioxide diffuse from the air into the mesophyll cells. Which two changes will increase the rate at which carbon dioxide diffuses into the mesophyll cells? [2 marks] Tick () two boxes. Decreased number of chloroplasts in the cells Decreased surface area of cells in contact with the air Increased carbon dioxide concentration in the air Increased number of stomata that are open Increased oxygen concentra