1. 1. The plasma membrane is composed primarily of _____. A
1. The plasma membrane is composed primarily of _____ A. phospholipids B. carbohydrates C. waxes D. nucleic acids
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2. 2. The tails of the phospholipids are _____. A. nonpolar B
2. The tails of the phospholipids are _____ A. nonpolar B. hydrophobic C. directed inwards in the bilayer D. all of the above
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3. 3. The amount of phospholipid extracted from red blood cells led researchers to propose that ____ A. the phospholipids form a single layer around the cell B. the phospholipids form a bilayer around the cell C. there are not enough phospholipids to create a membrane around the cell
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4. 4. Electron micrographs support the _____ model of the plasma membrane
4. Electron micrographs support the _____ model of the plasma membrane A. sandwich B. unit membrane C. fluid-mosaic
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5. 5. According to the fluid-mosaic model, _____ are partially or wholly embedded in a fluid phospholipid bilayer A. nucleic acids B. monosaccharides C. proteins D. triglycerides
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6. 6. All membranes appear the same in electron micrographs. True False
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7. 7. The plasma membrane is permeable to some nonlipid substances
7. The plasma membrane is permeable to some nonlipid substances True False
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8. 8. According to the fluid-mosaic model the hydrophilic heads of the phospholipids face the intra and extracellular fluids True False
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9. 9. Phospholipids are the only type of lipid in the plasma membrane
9. Phospholipids are the only type of lipid in the plasma membrane True False
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10. 10. The permeability of most membranes is reduced by the presence of _____ in the membrane A. nucleotides B. proteins C. cholesterol D. glycolipids
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11. 11. A sugar attached to a lipid is called a _____. A. glycoplipid B
11. A sugar attached to a lipid is called a _____ A. glycoplipid B. disaccharide C. monomer D. glycoprotein
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12. 12. The plasma membrane is "sugar-coated" by _____. A. glycolipids B
12. The plasma membrane is "sugar-coated" by _____ A. glycolipids B. gylcoproteins C. both A and B
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13. 13. The proper functioning of some of the membrane proteins depends on the fluidity of the membrane True False
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14. 14. Which of the following lipids may be found in the plasma membrane
14. Which of the following lipids may be found in the plasma membrane? A. phospholipids B. cholesterol C. glycolipids D. all of the above.
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15. 15. The two halves of the plasma membrane are identical. True False
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16. 16. The plasma membrane is a stiff and rigid structure. True False
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17. 17. Glycolipids and glycoproteins vary from __________. A
17. Glycolipids and glycoproteins vary from __________ A. species to species B. individual to individual C. cell to cell D. all of the above
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18. 18. Particular molecules or ions freely cross the plasma membrane with assistance from _____ A. receptor proteins B. cell recognition proteins C. channel proteins D. enzymatic proteins
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19. 19. Transplant rejections are the result of the immune system's response to foreign glycoproteins and glycolipids True False
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20. 20. A person's blood type is determined by the presence of particular _____ in the red blood cells' membranes A. phospholipids B. glycoproteins C. steroids D. nucleic acids
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21. 21. Receptor proteins in the plasma membrane bind to any kind of molecule. True False
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22. 22. The "fingerprints" of the cell are _____. A
22. The "fingerprints" of the cell are _____ A. the carbohydrate chains of glycolipids and glycoproteins B. the sequence of amino acids in the channel proteins C. the types of fatty acids in the phospholipids D. the phosphate groups of the phospholipids
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23. 23. Peripheral proteins are found within the plasma membrane
23. Peripheral proteins are found within the plasma membrane True False
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24. 24. Lipid-soluble molecules move freely across the plasma membrane
24. Lipid-soluble molecules move freely across the plasma membrane True False
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25. 25. Which of the following does NOT move freely (without energy or a carrier protein) across the plasma membrane? A. H2O B. steroids C. Na D. O2
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26. 26. Which of the following requires energy. A. diffusion B
26. Which of the following requires energy? A. diffusion B. active transport C. osmosis D. facilitated transport
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27. 27. During diffusion molecules move from areas of low concentration to areas of high concentration True False
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28. 28. The hydrophobic tails of the phospholipids in the plasma membrane are what prevent ions and charged molecules from freely crossing the membrane True False
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29. 29. The sugar you stir into your coffee is an example of a _____. A
29. The sugar you stir into your coffee is an example of a _____ A. solvent B. solute
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30. 30. Osmosis is specifically about the movement of _____ in and out of cells A. sugars B. proteins C. water D. oxygen
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31. 31. If the inside of a cell is 1% NaCl, which solution is isotonic to the cell? A. 0.01% NaCl B. 0.1% NaCl C. 1% NaCl D. 10% NaCl
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32. 32. If the inside of a cell is 1% NaCl, which solution is hypertonic to the cell? A. 0.01% NaCl B. 0.1 % NaCl C. 1% NaCl D. 10% NaCl
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33. 33. Plants wilt when you don't water them due to decreased turgor pressure . True False
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34. 34. A hypotonic solution has fewer solutes than the cell. True False
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35. 35. Macromolecules are transported into the cell by __________. A
35. Macromolecules are transported into the cell by __________ A. exocytosis B. osmosis C. diffusion D. pinocytosis
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36. 36. Solutions that cause cells to neither gain nor lose water are known as ______ solutions A. isotonic B. hypertonic C. hypotonic
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37. 37. When a plant cell is placed in a hypotonic solution which of the following will occur? A. The cell will swell and burst B. nothing C. The central vacuole gains water D. The cell will shrink or shrivel up.
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38. 38. The term hemolysis refers to ______. A. normal red blood cells B
38. The term hemolysis refers to ______ A. normal red blood cells B. red blood cells that burst after being placed in a hypotonic solution C. shrinking of the cytoplasm after a cell is placed in a hypertonic solution D. the loss of turgor pressure in a plant cell
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39. 39. Carrier proteins are required for _____. A. osmosis B
39. Carrier proteins are required for _____ A. osmosis B. facilitated transport C. active transport D. both B and C
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40. 40. Osmotic pressure affects _____ A. water retention by the kidneys B. water uptake from tissue fluids by the capillaries C. water absorption from the large intestine D. all of the above
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41. 41. The chloride ion channels malfunction in persons with __________, leading to the symptoms of this inherited disease/disorder A. diabetes B. Down syndrome C. cystic fibrosis D. AIDS
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42. 42. Which of the following correctly describes facilitated transport? A. It requires the expenditure of energy B. Molecules move from high concentration to low concentration C. Vacuoles form to move materials D. all of the above
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43. 43. Which of the following correctly describes active transport. A
43. Which of the following correctly describes active transport? A. carrier proteins are needed B. it requires the expenditure of energy C. molecules move from areas of low concentration to areas of high concentration D. all of the above.
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44. 44. Cells that do a lot of active transport have many _____. A
44. Cells that do a lot of active transport have many _____ A. mitochondria B. nuclei C. chloroplasts D. plasmids
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45. 45. The sodium-potassium pump, associated with muscle and nerve cells, moves Na+ to the outside of the cell and K+ to the inside of the cell True False
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46. 46. The functioning of the sodium-potassium pump depends upon the availability of ATP. True False
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47. 47. Insulin leaves insulin-secreting cells by _____. A. phagocytosis B
47. Insulin leaves insulin-secreting cells by _____ A. phagocytosis B. receptor-mediated endocytosis C. osmosis D. exocytosis
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48. 48. Macrophages, immune system cells, engulf bacteria by _____. A
48. Macrophages, immune system cells, engulf bacteria by _____ A. exocytosis B. facilitated transport C. phagocytosis D. osmosis
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49. 49. Specific molecules enter cells by _____. A. phagocytosis B
49. Specific molecules enter cells by _____ A. phagocytosis B. receptor mediated endocytosis C. diffusion D. osmosis
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50. 50. The peptide hormone, follicle stimulating hormone, would activate its specific target cells by _____ A. diffusing into the cells B. binding a receptor protein in the plasma membranes C. phagocytosis
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51. 51. Bacteria, fungi and plants all have an extracellular component called a cell wall. True False
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52. 52. Woody plants are characterized by _____ A. a secondary cell wall B. the absence of a cell wall C. numerous desmosomes D. collagen
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53. 53. The extracellular matrix of animal cells supports them and fills the spaces between the cells True False
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54. 54. Plant cells are able to exchange materials through _____. A
54. Plant cells are able to exchange materials through _____ A. gap junctions B. plasmodesmata C. tight junctions D. desmosomes
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55. 55. People may get injections of _____, a component of the extracellular matrix of animal cells, to get rid of their wrinkles A. collagen B. cholesterol C. cellolose D. chromatin
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56. 56. Organs with tissues that get stretched a lot like the heart and bladder are characterized by _____ A. tight junctions B. adhesion junctions C. plasmodesmata D. gap junctions
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57. 57. Tight junctions between cells make tissues leakproof. True False
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58. 58. Heart cells are able to contract in unison because of the flow of ions through _____ A. gap junctions B. tight junctions C. plasmodesmata D. adhesion junctions
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59. 59. All cells have a _____. A. cell wall B. plasma membrane C
59. All cells have a _____ A. cell wall B. plasma membrane C. nucleus D. flagellum
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60. 60. The plasma membrane allows anything to move freely in or out of the cell. True False
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