1. How many fatty acid molecules combine with a glycerol to form a phospholipid molecule? A. 1 B. 2 C. 3 D. 4

Transcription

1 Topic 3: Movement of substances across cell membrane 1. How many fatty acid molecules combine with a glycerol to form a phospholipid molecule? A. 1 B. 2 C. 3 D. 4 Directions: Questions 2 and 3 refer to the diagram below which shows the fluid mosaic model of the cell membrane. 2. What is/are the role(s) of structure A? (1) For cell recognition. (2) For carrying water-soluble substances across cell membrane. (3) For supporting the cell. A B C D (1) only (2) only (1) and (2) only (1) and (3) only 3. Which of the following correctly shows the path through which sugar and alcohol molecules pass through the membrane? Sugar Alcohol A Path X Path X B Path X Path Y C Path Y Path X D Path Y Path Y Directions: The following two questions refer to the diagram below, which shows the structure of a cell membrane.

2 X outside of cell Y inside of cell 4. Which of the following is the correct match of X and Y? X Y A glucose protein molecule B oxygen water-repelling tail C carbon dioxide water-loving head D water carbohydrate molecule 5. According to the fluid mosaic model of cell membrane, which of the following statements is true about membrane phospholipids? A. They have water-loving tails in the interior of the membrane. B. They occur in a bilayer, with membrane proteins restricted to the surface of the membrane. C. They are free to depart from the membrane and dissolve in the surrounding aqueous solution. D. They can move laterally along the plane of the membrane. 6. A selectively permeable membrane is best described as a membrane which allows A. Some molecules to pass through but not others B. Only water molecules to pass through but not other solute molecules C. water molecules to pass through but not larger molecules D. glucose molecules to pass through but not sucrose molecules 7. A cell that is hypertonic... A. will experience a net movement of water into the cell from the surrounding environment. B. has a lower concentration of solutes than the surrounding environment. C. will experience a net movement of water out of the cell into the surrounding environment. D. is in danger of plasmolysis. 8. Which of the following statements about diffusion is correct? A. It is due to the random movement of the particles that have kinetic energy. B. It requires an additional input of energy. C. It takes place only with a differentially permeable membrane.

3 D. It only refers to the movement of water molecules. 9. The following unicellular organism, Amoeba, was placed into a beaker of distilled water. Which of the following shows the appearance of Amoeba after 15 minutes? A B C D 10. Plasmolysis refers to the situation that A. water enters a cell by osmosis. B. an animal cell shrinks. C. a cell is put in a hypotonic solution. D. a plant cell is flaccid. 11. What will happen to cell X if it is soaked in (1) a hypotonic solution or (2) a hypertonic solution? cell X (1) (2) A bursts becomes plasmolysed B becomes plasmolysed bursts C turgid becomes plasmolysed D becomes plasmolysed turgid 12. The diagram shows an experiment on diffusion.

4 More sugar diffuses out of the tubing than that diffuses in. What is the concentration of sugar in solution X? A 10% B 20% C 30% D 40% 13. Microorganisms could not grow on honey because microorganisms: A. Cannot oxidize honey B. Are dehydrated by the sugars solution in the honey C. Cannot absorb the honey D. Contains no enzymes to digest honey 14. Which of the following is not an example of osmosis? A. Bursting of red blood cells in water B. Plant cells become turgid in water C. Swelling of a piece of bread in water D. Absorption of water by root hairs 15. Glucose diffuses slowly through artificial phospholipid bilayers. The cells lining the small intestine, however, rapidly move large amount of glucose from the intestinal lumen into their cytoplasm which has a low glucose concentration. Using this information, which transport mechanism is most probably functioning in the intestinal cells? A. phagocytosis B. active transport C. diffusion D. osmosis 16. Directions: Questions 16 and 17 refer to the diagram below shows how a unicellular organism obtains food particles. 16. The food particle can enter the unicellular organism because (1) the organism can move towards the food particle.

5 (2) the cell membrane of the organism is fluid in nature. (3) the cell membrane of the organism is mosaic in nature. A (1) and (2) only B (1) and (3) only C (2) and (3) only D (1), (2) and (3) 17. Which of the following components forms vesicles during phagocytosis? A. Rough ER B. Ribosome C. Nucleolus D. Cell membrane 18. Compared with other processes of transport across the cell membrane, which of the following is/are unique to phagocytosis? (1) Cell membrane is used to enclose the substance to be transported. (2) The substance to be transported could be a cell. (3) The transport is against the concentration gradient. A. (1) and (2) only B. (1) and (3) only C. (2) and (3) only D. (1), (2) and (3) 19. Which of the following is an importance of active transport in our body? A. It is the fastest way of absorbing materials. B. It requires no energy. C. It allows the greatest amount of materials to be absorbed when compared with diffusion and osmosis. D. It helps the absorption of essential materials against a concentration gradient. 20. The diagram below shows the set-up used to investigate osmosis. liquid level dialysis tubing solution X solution Y Which of the following combinations is correct? Solution X Solution Y Change in the height of the liquid level A. distilled water 10% sucrose decrease B. 10% sucrose distilled water increase C. 10% sucrose 15% sucrose increase D. 10% sucrose 5% sucrose increase

6 21. The table below shows the contents of three test tubes for investigating the effect of solutions of different solute concentrations on red blood cells. Test tube Contents X blood sample and hypotonic solution Y blood sample and isotonic solution Z blood sample and hypertonic solution A drop of contents from each test tube is observed under the microscope. Which of the following is the correct observation? Test tube Observation A X red blood cells shrink B Y red blood cells remain unchanged C Z red blood cells become turgid D Z red blood cells burst 22. The diagram below shows the appearance of a plant cell immersed in an isotonic solution. nucleus vacuole cell wall cell membrane cytoplasm Which of the following diagrams correctly represents the appearance of the plant cell after immersion in a hypertonic solution? B. D. 23. What is/are needed for diffusion to occur? (1) a concentration gradient of solutes (2) a differentially permeable membrane (3) a supply of ATP A. (1) only B. (1) and (2) only C. (1) and (3) only D. (1), (2) and (3) 24. The graph below shows the change in the weight of a potato strip when it is immersed in salt solution of different concentrations.

7 loss (g) gain (g) Change in weight of potato strip with concentration of salt solution J K L M N O concentration of salt in solution (%) The reason for joining the points by a best straight line is that A. averaging experimental results allows one to establish relationships. B. the individual points are wrong. C. the individual points are assumptions, while the best straight line is a fact. D. the best straight line shows the accuracy of the experimental results. 25. Which of the following statements about organelles is correct? A. They are all bounded by a double membrane. B. They are the units making up an organ. C. They are sub-cellular structures. D. They are only found in eukaryotes. 26. A red blood cell immersed in distilled water will burst while a plant cell will not. Which of the following can explain such difference? A. Cell wall is absent in the red blood cell B. Nucleus is absent in the red blood cell C. The cell membrane of the plant cell is impermeable to water D. The plant cell stores starch instead of glucose 27. There are two cups of salt water with different concentrations. When diffusion of water molecules reaches equilibrium, it means: A. No water movement will be taken place B. No net water movement will be taken place C. No salt molecules will move D. Diffusion of water molecules from higher water potential to the lower 28. The diagram below shows two salt solutions separated by a selectively permeable membrane. In which of the following cases will there be net movement of water from P to Q?

8 Concentration of P Concentration of Q A. 0.1% 0.1% B. 0.1% 0.5% C. 0.5% 0.1% D % Directions: Questions 29 to 31 refer to the experiment below. 29. What will happen to the sugar crystals inside potatoes P and Q after an hour? P Q A. dissolve dissolve B. no change dissolve C. dissolve no change D. no change no change 30. Which process(es) is/are responsible for the changes mentioned above? A. Active transport B. Diffusion C. Osmosis D. Diffusion and osmosis 31. In doing this experiment, the skin of the potatoes must be peeled. Why? A. The skin contains sugar which will affect the results. B. The skin contains many soluble substances.

9 C. The skin consists of cells with higher osmotic potential. D. The skin consists of impermeable dead cells. Directions: Questions 32 to 35 refer to the experiment below, which shows an experiment which studies osmosis. 32. Which of the following graphs represents the change of the liquid level from the start of the experiment to the time when equilibrium has been reached? Key: H = Relative height of the liquid level 33. Which of the following can increase the final height of the liquid level in the capillary tube? (1) raising the temperature of water to 30 (2) using a capillary tube with a smaller internal diameter (3) using a 10% sucrose solution A. (1) and (2) only B. (2) and (3) only C. (1) and (3) only D. (1), (2) and (3) 34. Which of the following can increase the rate of rise of the liquid level in the capillary tube?

10 (1) raising the temperature of water to 30 (2) using a capillary tube with a smaller internal diameter (3) using a 10% sucrose solution (4) using a larger beaker to hold more water A. (1) and (2) only B. (2) and (3) only C. (1), (2) and (3) D. (2), (3) and (4) 35. In this study, if a 5% glucose solution were used instead of the 5% sucrose solution and the dialysis tubing was permeable to glucose, which of the following graphs represents the rise of the liquid level from the start of the experiment to the time when equilibrium has been reached? Key: H = Relative height of the liquid level