1. How substances get in and out of cells Mainly based on the exercises from http://www.biology-resources.com/biology-questions.html IGCSE Revision Questions http://biodeluna.wordpress.com
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5. Which of the statements is an acceptable description of diffusion ? (i) The movement of water from a concentrated solution to a dilute solution across a partially permeable membrane. . (ii) The movement of a dissolved substance from a concentrated solution to a dilute solution across a partially permeable membrane. (iii) The movement of water from a dilute solution to a concentrated solution across a partially permeable membrane. (iv) The uptake of water by a living cell.
6. Which of the statements is an acceptable description of diffusion ? (i) The movement of water from a concentrated solution to a dilute solution across a partially permeable membrane. . (ii) The movement of a dissolved substance from a concentrated solution to a dilute solution across a partially permeable membrane. (iii) The movement of water from a dilute solution to a concentrated solution across a partially permeable membrane. (iv) The uptake of water by a living cell.
17. (a) a lower osmotic potential (water potential) than its own cytoplasm Plasmolysis (b) a higher osmotic potential (water potential) than its own cytoplasm.
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19. When meat is salted, bacteria cannot grow on it. Suggest a reason for this.
20. When a cell is respiring aerobically, which two gases are likely to be diffusing in and out of the cell, and in which direction will they be diffusing?
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24. water and iodine starch and glucose solutions A piece of dialysis (‘Visking’) tubing is knotted at one end water and iodine and filled with a 2 % starch solution mixed with a 10% glucose solution. The tube is immersed in.a test-tube of water to which iodine has been added. (a ) Predict what you will see after 30 minutes (i) in the starch and glucose solutions dialysis tube, (ii) in the test-tube, (iii) when you boil the liquid from the test-tube with Benedict's solution. (b) Give an explanation of these results.
