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OCR A biology 2020 depth (as level) paper & markscheme 2020

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OCR A biology 2020 depth (as level) paper & markscheme Tuesday 19 May 2020 Afternoon Time allowed: 1 hour 30 minutes Materials For this paper you must have: • a ruler with millimetre measureme... nts • a scientific calculator. Instructions • Use black ink or black ball-point pen. • Fill in the boxes at the top of this page. • Answer all questions. • You must answer the questions in the spaces provided. Do not write outside the box around each page or on blank pages. • 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). • Show all your working. • Do all rough work in this book. Cross through any work you do not want to be marked. Information • The marks for the questions are shown in brackets. • The maximum mark for this paper is 75. *JUN207401101* IB/M/Jun20/E12 7401/1 Answer all questions in the spaces provided. box Figure 1 shows the structure of molecules found in organisms. Figure 1 . Complete Table 1 by putting the correct letter, A, B, C or D, in the box next to each statement. Each letter may be used once, more than once, or not at all. [4 marks] Table 1 Letter Statement is a monomer in an enzyme’s active site is a monomer in cellulose is produced during photosynthesis and respiration forms a polymer that gives a positive result with a biuret test . Raffinose is a trisaccharide of three monosaccharides: galactose, glucose and fructose. The chemical formulae of these monosaccharides are: • galactose = C6H12O6 • glucose = C6H12O6 • fructose = C6H12O6 Give the number of carbon atoms, hydrogen atoms and oxygen atoms in a molecule of raffinose. box [1 mark] Number of carbon atoms Number of hydrogen atoms Number of oxygen atoms . A biochemical test for reducing sugar produces a negative result with raffinose solution. Describe a biochemical test to show that raffinose solution contains a non-reducing sugar. [3 marks] Turn over ► [Show More]

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