VJC 2023 H2 9744 P2 QP

VICTORIA JUNIOR COLLEGE PRELIMINARY EXAMINATION HIGHER 2 CANDIDATE NAME: ……………………………………………………….………………. CT GROUP: ………………..……… BIOLOGY Paper 2 Structured Questions 9744/02 14 September 2023 2 hours Candidates answer on the Question Paper. No Additional Materials are required. READ THESE INSTRUCTIONS FIRST Write your name and CT group in the spaces at the top of this page. Write in dark blue or black pen. You may use an HB pencil for any diagrams or graphs. Do not use staples, paper clips, glue or correction fluid. Answer all questions in the spaces provided on the Question Paper. The use of an approved scientific calculator is expected, where appropriate. You may lose marks if you do not show your working or if you do not use appropriate units. The number of marks is given in bracket [ ] at the end of each question or part question. Question Marks 1 /9 2 /12 3 /9 4 /9 5 /10 6 /12 7 /9 8 /8 9 /12 10 /5 11 /5 Total 100 This document consists of 24 printed pages. [Turn over]

2 Answer all questions. 1 The cell surface membrane regulates the movement of different substances via different mechanisms. Table 1.1 shows the results from an investigation to determine how two different drugs A and B enter animal cells. Table 1.1 concentration of drug A in container / arbitrary units concentration of drug A inside the cells after 5 minutes / arbitrary units concentration of drug B in container / arbitrary units concentration of drug B inside the cells after 5 minutes / arbitrary units 0 0 0 0 5 5 5 4 10 10 10 7 15 15 15 11 20 19 20 13 25 24 25 13 Cells which did not contain either drug were placed into separate containers. Different concentrations of each drug were added and after 5 minutes, the drug concentration in the cells was measured. (a) Based on the data shown in Table 1.1, (i) state the chemical nature of drugs A and B. ....................................................................................................................................................... .................................................................................................................................................. [1] (ii) explain the difference between the transport of drugs A and B. ....................................................................................................................................................... ....................................................................................................................................................... ....................................................................................................................................................... ....................................................................................................................................................... ....................................................................................................................................................... ....................................................................................................................................................... ....................................................................................................................................................... .................................................................................................................................................. [3]

3 (b) Viruses make use of certain properties of the cell membrane to facilitate their release from the host cell. Fig. 1.1 shows such a process. Fig. 1.1 (i) Explain clearly how the structure of the cell membrane facilitates this process. ....................................................................................................................................................... ....................................................................................................................................................... ....................................................................................................................................................... ....................................................................................................................................................... ....................................................................................................................................................... ....................................................................................................................................................... ....................................................................................................................................................... .................................................................................................................................................. [3] (ii) Contrast the process seen in Fig 1.1 with the process in which HIV virus enters the host cell. ....................................................................................................................................................... ....................................................................................................................................................... ....................................................................................................................................................... ....................................................................................................................................................... ....................................................................................................................................................... .................................................................................................................................................. [2] [Total: 9]

4 2 (a) Starch molecules are the main storage molecules in many types of cereal grain, such as the grain of the barley plant. When the seed inside a barley grain germinates, enzymes are synthesised to catalyse the hydrolysis of the starch molecules. (i) Starch is a mixture of two different molecules. Name these two molecules. ....................................................................................................................................................... .................................................................................................................................................. [1] (ii) Describe two features of starch that allows it to be a good storage molecule. ....................................................................................................................................................... ....................................................................................................................................................... ....................................................................................................................................................... .................................................................................................................................................. [2]

5 Two of the enzymes synthesised by the barley seed are α -amylase and maltase. These are involved in the hydrolysis of the stored starch during seedling formation. In the food industry, the starch extracted from barley seeds (barley starch) is used in the production of sugar syrups. Fig. 2.1 summarises the reactions catalysed by α-amylase in the production of maltose syrup and by maltase in the production of glucose syrup. α-amylase barley starch maltose maltase mal