Chapter 22: The Living Cell - Ironmtn.wordpress.com · Web viewSome cells lack cell membranes and cell walls. d. Meiosis produces cells with half the normal complement of DNA. Meiosis

Chapter 21The Living Cell:

What is the smallest living thing?

1. Which of the following is a cell?a. chicken egg yolkb. bacteriumc. spermd. nervee. all of the above

Ans: eLink To: The Nature and Variety of CellsDifficulty Level: Easy

2. Which phrase best describes the inside of a cell?a. comprised of protoplasmb. full of diverse structuresc. basically a vacuumd. has not yet been thoroughly researchede. only a & b

Ans: bLink To: The Nature and Variety of CellsDifficulty Level: Easy

3. What is NOT a function of the cell membrane?a. reproductionb. separates inside from outsidec. transmits materials outside to insided. protectione. isolation

Ans: aLink To: How Does a Cell Work?Difficulty Level: Easy

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4. Following Hooke's identification of cells with a microscope, how long was it before scientists accepted the cell as the unit of life?a. two centuriesb. two decadesc. two yearsd. one centurye. Scientists accepted Hooke's discoveries right away.

Ans: aLink To: The Nature and Variety of CellsDifficulty Level: Easy

5. The most sophisticated optical microscopes today can magnify items more thana. 100 timesb. 1000 timesc. 10,000 timesd. 100,000 timese. none of the above

Ans: bLink To: The Nature and Variety of CellsDifficulty Level: Easy

6. The hydrophobic ends of a cell membrane's lipid bilayer area. pointed to the outside.b. pointed to the inside.c. pressed together.d. in contact with hydrophilic ends of lipids.e. not in contact with hydrophilic ends of lipids.

Ans: cLink To: How Does a Cell Work?Difficulty Level: Easy

7. Which pair of organelles transfers energy in the cell?a. cytoskeleton and nucleusb. mitochondria and chloroplastsc. chloroplasts and nucleusd. cell wall and vacuoles

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e. cell membrane and nucleus

Ans: bLink To: How Does a Cell Work?Difficulty Level: Easy

8. Which is true of ATP?a. ATP is a molecule.b. ATP is an energy carrier.c. ATP contains sugar.d. ATP contains phosphorous.e. all the above

Ans: eLink To: Metabolism: Energy and LifeDifficulty Level: Easy

9. In the process of photosynthesisa. electromagnetic radiation is converted to electric and magnetic energy.b. electromagnetic radiation is converted to lipids.c. light energy is metabolized.d. light energy is converted to atomic energy.e. light energy is converted to chemical energy.

Ans: eLink To: Metabolism: Energy and LifeDifficulty Level: Easy

10. An organelle not found in the cells of animals isa. Golgi apparatus.b. chloroplast.c. ribosome.d. mitochondrion.e. nucleus.

Ans: bLink To: Metabolism: Energy and LifeDifficulty Level: Easy

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11. A cell's receptor moleculea. is usually elliptical in shape.b. binds to a molecule to facilitate transfer across the cell membrane.c. cannot be "fooled" into recognizing viruses.d. is a solid framework of polymers.e. contains the cell's genetic material.


12. Which one of the following is in all cells?a. DNAb. chloroplastsc. nucleusd. vacuolese. cell wall

Ans: aLink To: Cell DivisionDifficulty Level: Easy

13. Which of the following is a stored energy end product of fermentation?a. glucoseb. alcoholc. yeastd. starche. lactic acid

Ans: bLink To: Metabolism: Energy and LifeDifficulty Level: Easy

14. What is the chief function of the mitochondria?a. to provide immunityb. to create energyc. to transfer energyd. to stimulate mobilitye. to initiate meiosis

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15. Which organelle gives the cell a shape?a. nucleusb. mitochondriac. chloroplastsd. cytoskeletone. all of the above

Ans: dLink To: How Does a Cell Work?Difficulty Level: Easy

16. Which of the following phrases would not be in the definition of photosynthesis?a. sunlight and chlorophyllb. carbon dioxide and waterc. oxygen and carbon dioxided. starches and fatse. sugars and starches

Ans: dLink To: Metabolism: Energy and LifeDifficulty Level: Easy

17. The end product for glycolysis isa. pyruvic acid and ATP.b. carbon dioxide and water.c. carbohydrates and oxygen.d. the Krebs cycle.e. ADP and alcohol.

Ans: aLink To: Metabolism: Energy and LifeDifficulty Level: Easy

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18. Chromosomesa. were first discovered in the nineteenth century.b. are long strands of DNA.c. come in pairs, located in the nucleus.d. vary in number with the species.e. all of the above

Ans: eLink To: Cell DivisionDifficulty Level: Easy

19. Fermentation in plants produces ________; fermentation in animals producesa. lactic acid, alcoholb. carbon dioxide; alcoholc. glucose; lactic acidd. alcohol; lactic acide. alcohol; carbon dioxide

Ans: dLink To: Metabolism: Energy and LifeDifficulty Level: Easy

True/ False

20. Anaerobic processes release more energy than aerobic processes.

Ans: FalseLink To: Metabolism: Energy and LifeDifficulty Level: Easy

21. The mitochondria are thought to be a recent cell mutation.

Ans: FalseLink To: How Does a Cell Work?Difficulty Level: Easy

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22. Only cells can produce other cells.

Ans: TrueLink To: The Nature and Variety of CellsDifficulty Level: Easy

23. Cytoplasm is the fluid that takes up spaces between the organelles of a cell.

Ans: TrueLink To: How Does a Cell Work?Difficulty Level: Easy

24. The resolving power of an electron microscope is limited by the wavelength of the light used to illuminate the specimen.


25. The primary difference between a prokaryote cell and a eukaryote cell is the nuclear membrane in the latter.


26. Chloroplasts in plant cells and mitochondria in animal cells are both energy-processing organelles.

Ans: TrueLink To: Metabolism: Energy and LifeDifficulty Level: Easy

27. Cell membranes can deform to encapsulate a particle and transport it within the cell.

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28. The cytoplasm is to a cell what a skeleton is to a horse.


29. ATP is a molecule that stores and carries energy in its phosphate bonds.


30. Some cells, like bacteria, do not have a nucleus.


31. Cellulose and other strong polymers give plant cells support by surrounding the plant cell membrane.


32. The Krebs cycle happens during the final stages of respiration.


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33. Adenosine triphosphate is an organic molecule that includes ribose sugar in its structure.


34. Describe the workings of an electron microscope.

Ans: An electron microscope overcomes the resolution limitations of an optical microscope by using the very small electron wavelengths to examine objects as small as atomic particles. In the electron microscope an electric current heats a tungsten filament in a strong electric field to produce an electron beam. Electrons boil off thenegatively charged tungsten wire and accelerate towards the positive end of a tube where ring-shaped electromagnets focus the electron beam. The beam strikes the sample, then hits a detector. The detector converts the beam into a high-resolution image.Link To: How Does a Cell Work?Difficulty Level: Easy

35. Outline the steps of mitosis in living cells.

Ans: The first step in mitosis is duplication of the chromosomes in the DNA of the nucleus. Next the nuclear membrane dissolves and fibers called “spindles” develop. The two matched sets of chromosomes migrate to the opposite ends of the cell. Finally, the nuclear membranes reform and the cell splits down the middle. The result is two cells, each with a set of chromosomes identical to the original.Link To: Cell DivisionDifficulty Level: Easy

36. Outline the steps of meiosis living cells use to produce gametes.

Ans: Meiosis begins with a one-to-one copying of the chromosomes, like the process of mitosis; however in meiosis paired chromosomes from father and mother can exchange material, "cross over." Therefore, at the end of the first stage, there are two cells with reassembled genetic material where there had been only one cell with material from father and mother on separate chromosomes. Next the chromosome pairs move to opposite ends of each cell. The two cells divide again, producing a total of four cells, each with half the normal complement of DNA. These chromosomes eventually become a part of the reproductive cells, sperm or ova gametes.Link To: Cell DivisionDifficulty Level: Easy

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37. Describe the workings of an optical microscope, also called a light microscope.

Ans: Visible light passes through a transparent sample on a transparent slide. The light goes through several lenses so that the magnified image ends at the viewer's eyepiece. The image can be magnified as much as 1,000 times but is limited by the resolving power (the wavelength of the light used).Link To: Metabolism: Energy and LifeDifficulty Level: Easy

38. What limits the resolving power of all microscopes?a. the wavelength of the light usedb. the wave frequency of the light usedc. the wave amplitude of the light usedd. the transparency of the objecte. all of the above

Ans: aLink To: The Nature and Variety of CellsDifficulty Level: Medium

39. Which is the best analogy for a cell membrane?a. wax covering the top of preservesb. bark on the outside of a treec. skin of a reptiled. ping pong balls covering a birdbathe. fish netting in the ocean

Ans: dLink To: How Does a Cell Work?Difficulty Level: Medium

40. What advantage does the structure of the cell membrane afford the cell?a. prevents invasion by virusesb. the lowest possible energy statec. mediates temperature extremesd. can be adapted to reproductione. dehydrates cell molecules

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Ans: bLink To: How Does a Cell Work?Difficulty Level: Medium

41. Which of the following statements about cells is true?a. All cells are microscopic in size.b. Only prokaryotes carry genetic information in nuclei.c. Some cells lack cell membranes and cell walls.d. Meiosis produces cells with half the normal complement of DNA.e. All of the above are false.

Ans: dLink To: Cell DivisionDifficulty Level: Medium

42. What does current theory say about the origin of the nucleus?a. A small cell was engulfed by a larger cell.b. A large cell was broken apart by a smaller cell.c. A large cell was merged with another large cell.d. Two small cells formed a symbiotic relationship.e. The first cell contained a nucleus as a basic component.

Ans: aLink To: How Does a Cell Work?Difficulty Level: Medium

43. Which statement is false?a. Aerobic reactions yield more energy per molecule of glucose than anaerobic reactions.b. Anaerobic reactions yield more energy per molecule of glucose than aerobic reactions.c. The Krebs cycle occurs in aerobic conditions.d. Fermentation is an anaerobic process.e. Respiration is an aerobic process.

Ans: bLink To: How Does a Cell Work?Difficulty Level: Medium

44. The more chromosomes an organism has, the more complex it is.

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Ans: FalseLink To: Cell DivisionDifficulty Level: Medium

45. During photosynthesis, the chlorophyll molecule in green plants can absorb the Sun's energy only in the wavelength of green light.

Ans: FalseLink To: Metabolism: Energy and LifeDifficulty Level: Medium

46. Assembling an ATP molecule is an endothermic process in the cell.

Ans: TrueLink To: Metabolism: Energy and LifeDifficulty Level: Medium

47. Receptor molecules in the cell membrane are open gates to all molecules with hydrogen bonds.

Ans: FalseLink To: How Does a Cell Work?Difficulty Level: Medium

48. Name and describe the function of three cell organelles.

Ans: Table 22-1 describes 13 organelles and their functions. The nucleus (stores DNA, controls the cell chemistry); endoplasmic reticulum (contributes to protein and lipid synthesis); mitochondria (release energy from food by metabolism); chloroplasts (site of photosynthesis in plants); ribosomes (site of protein synthesis); nucleoli (manufactureof the subunits of ribosomes); Golgi apparatus (processes proteins previously synthesized at the ribosomes); lysomes (contains digestive enzymes for breakdown of wastes); vesicles (small containers for chemical raw materials); cytoskeleton (provides cell structure and internal transport of vesicles); vacuoles (waste and water storage in plants); amyloplasts (storage of starch in plants); plasmodesmata (water conduits between plant cells).Link To: How Does a Cell Work?Difficulty Level: Medium

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49. Briefly define and describe the process of glycolysis.

Ans: Glycolysis is the first stage in the process of extracting energy from glucose. The glycolysis process takes nine steps, each controlled by a separate enzyme. The end products are two pyruvic acid molecules, each with three carbon atoms. (The original glucose molecule had six linked carbon atoms.) In addition to the two pyruvic acids formed during glycolysis, six-to-eight molecules of ATP are also produced in the mitochondria. The ATP carries the energy used later in respiration.Link To: Metabolism: Energy and LifeDifficulty Level: Medium

50. What is ATP and what is its part in the energy transfer within a cell?

Ans: ATP, Adenosine triphosphate, is a molecule containing three phosphate groups (phosphorous and oxygen atoms), a ribose sugar, and the base adenine. Energy was stored in this molecule when the phosphate groups were added to the end of the ribose sugar. When these phosphate groups are removed, the stored energy is released and is made available to drive other chemical reactions within the cell. In chemical shorthand: ATP—->ADP + PO4 + energyLink To: Metabolism: Energy and LifeDifficulty Level: Medium

51. What is the difference between anaerobic and aerobic processes?

Ans: Energy for living organisms can be generated in two distinct ways: respiration, which requires oxygen and is called aerobic; and fermentation, which can proceed without oxygen and is called anaerobic.Link To: Metabolism: Energy and LifeDifficulty Level: Medium

52. Discuss the statement “Geometry is destiny.” Use the molecular perspective in your answer.

Ans: Form follows function.Link To: The Nature and Variety of CellsDifficulty Level: Medium

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53. Compare and contrast eukaryotes and prokaryotes.

Ans: Prokaryotes are more primitive without cellular organelles bound in membranes.Link To: How Does a Cell Work?Difficulty Level: Medium

54. Discuss several common cell shapes and how these shapes influencethe function the cell performs.

Ans: Elongated cells in muscles exert force when contracting. Dendritic ends of nerve cells enable impulse transmission. Sperm cells have “tails” for motility in a fluid. For strength and structure, plant cells can have a cell wall made of cellulose and polymers. For mobility, the amoebae can flow into different shapes.Link To: The Nature and Variety of CellsDifficulty Level: Hard

55. What is the evolutionary advantage for a cell to expend energy in meiosis?

Ans: Although simple cloning of cells is possible with mitosis, the amount of genetic diversity is greatly increased by meiosis. With gamete diversity maximized, a population has a greater chance of survival. Link To: Cell DivisionDifficulty Level: Hard

56. Describe the process by which materials move across a cell membrane.

Ans: Cell membranes use channels and molecular openings as gatekeepers to transfer substances. Potassium and sodium ions are two examples of specific materials allowed to go back and forth through the cell membrane. The cell membrane also has molecule-specific receptors that bind to a unique type of molecule in the cell environment. The membrane itself is capable of “wrapping around” certain substances to carry them into or out of the cell. Viruses can gain entrance across the cell membrane by copying the shape of molecules the receptors expect.Link To: How Does a Cell Work?Difficulty Level: Hard

57. When an athlete's muscles get tired and sore during an athletic event, what is the biochemical explanation?

Ans: Once the athlete has used all oxygen available to his muscles for strenuous exertion, the muscles will use the "back-up" anaerobic process of fermentation to get energy. The end product

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of fermentation is lactic acid, which causes the stiffness as it accumulates in the cells. When the athlete rests and breathes in more oxygen, the lactic acid is exhaled as CO2 and the muscles can operate aerobically again.Link To: Metabolism: Energy and LifeDifficulty Level: Hard

58. At the cellular and molecular level, in what key ways are plants and animals the same? In what essential ways are they different? How do these differences give the organism an advantage in its life strategies?

Ans: Cellular respiration is the same; plants have chloroplasts, which allows them to make their own food.Link To: Metabolism: Energy and LifeDifficulty Level: Hard

59. If there were a common ancestor from which all life evolved, what would this ancestor be like? Use principles of biochemistry to describe such an organism.

Ans: Answers will vary. All life is based on DNA, which must be transferred and transformed.Link To: Metabolism: Energy and LifeDifficulty Level: Hard

60. Discuss what advances have to be made in molecular biology before individuals with lower spinal cord injuries can have normal use of their arms and legs.

Ans: Neurons have to grow back and currently there is no means to stimulate their growth.Link To: The Nature and Variety of CellsDifficulty Level: Hard

61. Which process is the basis for all life on earth: respiration, glycolysis or photosynthesis? Defend your answer.

Ans: Answers will vary and can include the extremeophiles and/or that with photosynthesis respiration and glycolysis can and does occur.Link To: Metabolism: Energy and LifeDifficulty Level: Hard

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62. What kind of evidence do we have for a biochemical basis for evolution? In your answer, trace the possible evolution of the single cell to more complex organisms.

Ans: The process of glycosis is found from the simplest through the most complex cells; this is the difference in high metabolism and low therefore more use of glycogen. The simpler processes can be found within the more complex processes. Fermentation came before respiration.Link To: Metabolism: Energy and LifeDifficulty Level: Hard

63. If a cell continues via mitosis, do they ever die?

Ans: Answers will vary but should be logical with respect to cellular respiration.Link To: Cell DivisionDifficulty Level: Hard

64. Most life on the surface of the earth depends on oxidation and photosynthesis. Give an example that does not.

Ans: Any type of anaerobic system does not.Link To: Metabolism: Energy and LifeDifficulty Level: Hard

65. Is there any structural evidence for evolution, why or why not?

Ans: Mitochondrion looks like a primitive cell inside of a cell - one example.Link To: How Does a Cell Work?Difficulty Level: Hard

66. Why are there so few (only six) limiting elements at the molecular level?

Ans: The higher the number of necessary elements, the harder it would be to maintain the cell’s health. All form covalent bonds.Link To: How Does a Cell Work?Difficulty Level: Hard

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67. Can a single cell grow to be size of a 10-pound house cat? Why or why not?

Ans: Answers will vary, but generally there is a size limit because of the cell’s ability to transport energy across its mass.Link To: How Does a Cell Work?Difficulty Level: Hard

68. Compare and contrast meiosis with mitosis. Do these two processes occur in different cells? Why or why not?

Ans: Mitosis occurs in all cells while mitosis only occurs in the sex cells. Meiosis starts with mitosis then undergoes a second ‘split’ to produce gametes.Link To: Cell DivisionDifficulty Level: Hard

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Chapter 22: The Living Cell - Ironmtn.wordpress.com · Web viewSome cells lack cell membranes and cell walls. d. Meiosis produces cells with half the normal complement of DNA. Meiosis