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Chapter 21
The Living Cell:
What is the smallest living thing?
1. Which of the following is a cell?
a. chicken egg yolk
b. bacterium
c. sperm
d. nerve
e. all of the above
Ans: e
Link To: The Nature and Variety of Cells
Difficulty Level: Easy
2. Which phrase best describes the inside of a cell?
a. comprised of protoplasm
b. full of diverse structures
c. basically a vacuum
d. has not yet been thoroughly researched
e. only a & b
Ans: b
Link To: The Nature and Variety of Cells
Difficulty Level: Easy
3. What is NOT a function of the cell membrane?
a. reproduction
b. separates inside from outside
c. transmits materials outside to inside
d. protection
e. isolation
Ans: a
Link 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 centuries
b. two decades
c. two years
d. one century
e. Scientists accepted Hooke's discoveries right away.
Ans: a
Link To: The Nature and Variety of Cells
Difficulty Level: Easy
5. The most sophisticated optical microscopes today can magnify items more than
a. 100 times
b. 1000 times
c. 10,000 times
d. 100,000 times
e. none of the above
Ans: b
Link To: The Nature and Variety of Cells
Difficulty Level: Easy
6. The hydrophobic ends of a cell membrane's lipid bilayer are
a. 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: c
Link To: How Does a Cell Work?
Difficulty Level: Easy
7. Which pair of organelles transfers energy in the cell?
a. cytoskeleton and nucleus
b. mitochondria and chloroplasts
c. chloroplasts and nucleus
d. cell wall and vacuoles
e. cell membrane and nucleus
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Ans: b
Link 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: e
Link To: Metabolism: Energy and Life
Difficulty Level: Easy
9. In the process of photosynthesis
a. 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: e
Link To: Metabolism: Energy and Life
Difficulty Level: Easy
10. An organelle not found in the cells of animals is
a. Golgi apparatus.
b. chloroplast.
c. ribosome.
d. mitochondrion.
e. nucleus.
Ans: b
Link To: Metabolism: Energy and Life
Difficulty Level: Easy
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11. A cell's receptor molecule
a. 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.
Ans: b
Link To: How Does a Cell Work?
Difficulty Level: Easy
12. Which one of the following is in all cells?
a. DNA
b. chloroplasts
c. nucleus
d. vacuoles
e. cell wall
Ans: a
Link To: Cell Division
Difficulty Level: Easy
13. Which of the following is a stored energy end product of fermentation?
a. glucose
b. alcohol
c. yeast
d. starch
e. lactic acid
Ans: b
Link To: Metabolism: Energy and Life
Difficulty Level: Easy
14. What is the chief function of the mitochondria?
a. to provide immunity
b. to create energy
c. to transfer energy
d. to stimulate mobility
e. to initiate meiosis
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Ans: b
Link To: How Does a Cell Work?
Difficulty Level: Easy
15. Which organelle gives the cell a shape?
a. nucleus
b. mitochondria
c. chloroplasts
d. cytoskeleton
e. all of the above
Ans: d
Link 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 chlorophyll
b. carbon dioxide and water
c. oxygen and carbon dioxide
d. starches and fats
e. sugars and starches
Ans: d
Link To: Metabolism: Energy and Life
Difficulty Level: Easy
17. The end product for glycolysis is
a. pyruvic acid and ATP.
b. carbon dioxide and water.
c. carbohydrates and oxygen.
d. the Krebs cycle.
e. ADP and alcohol.
Ans: a
Link To: Metabolism: Energy and Life
Difficulty Level: Easy
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Chapter 21
18. Chromosomes
a. 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: e
Link To: Cell Division
Difficulty Level: Easy
19. Fermentation in plants produces ________; fermentation in animals produces
a. lactic acid, alcohol
b. carbon dioxide; alcohol
c. glucose; lactic acid
d. alcohol; lactic acid
e. alcohol; carbon dioxide
Ans: d
Link To: Metabolism: Energy and Life
Difficulty Level: Easy
True/ False
20. Anaerobic processes release more energy than aerobic processes.
Ans: False
Link To: Metabolism: Energy and Life
Difficulty Level: Easy
21. The mitochondria are thought to be a recent cell mutation.
Ans: False
Link To: How Does a Cell Work?
Difficulty Level: Easy
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22. Only cells can produce other cells.
Ans: True
Link To: The Nature and Variety of Cells
Difficulty Level: Easy
23. Cytoplasm is the fluid that takes up spaces between the organelles of a cell.
Ans: True
Link 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.
Ans: False
Link To: How Does a Cell Work?
Difficulty Level: Easy
25. The primary difference between a prokaryote cell and a eukaryote
cell is the nuclear membrane in the latter.
Ans: True
Link To: How Does a Cell Work?
Difficulty Level: Easy
26. Chloroplasts in plant cells and mitochondria in animal cells are both energy-processing
organelles.
Ans: True
Link To: Metabolism: Energy and Life
Difficulty Level: Easy
27. Cell membranes can deform to encapsulate a particle and transport it within the cell.
Ans: True
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Link To: How Does a Cell Work?
Difficulty Level: Easy
28. The cytoplasm is to a cell what a skeleton is to a horse.
Ans: False
Link To: How Does a Cell Work?
Difficulty Level: Easy
29. ATP is a molecule that stores and carries energy in its phosphate bonds.
Ans: True
Link To: Metabolism: Energy and Life
Difficulty Level: Easy
30. Some cells, like bacteria, do not have a nucleus.
Ans: False
Link To: How Does a Cell Work?
Difficulty Level: Easy
31. Cellulose and other strong polymers give plant cells support by surrounding the plant cell
membrane.
Ans: True
Link To: How Does a Cell Work?
Difficulty Level: Easy
32. The Krebs cycle happens during the final stages of respiration.
Ans: True
Link To: Metabolism: Energy and Life
Difficulty Level: Easy
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33. Adenosine triphosphate is an organic molecule that includes ribose sugar in its structure.
Ans: True
Link To: Metabolism: Energy and Life
Difficulty Level: Easy
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 the
negatively charged tungsten wire and accelerate towards the positive end of a tube where ringshaped 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 Division
Difficulty 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 Division
Difficulty 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 Life
Difficulty Level: Easy
38. What limits the resolving power of all microscopes?
a. the wavelength of the light used
b. the wave frequency of the light used
c. the wave amplitude of the light used
d. the transparency of the object
e. all of the above
Ans: a
Link To: The Nature and Variety of Cells
Difficulty Level: Medium
39. Which is the best analogy for a cell membrane?
a. wax covering the top of preserves
b. bark on the outside of a tree
c. skin of a reptile
d. ping pong balls covering a birdbath
e. fish netting in the ocean
Ans: d
Link 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 viruses
b. the lowest possible energy state
c. mediates temperature extremes
d. can be adapted to reproduction
e. dehydrates cell molecules
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Ans: b
Link 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: d
Link To: Cell Division
Difficulty 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: a
Link 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: b
Link 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: False
Link To: Cell Division
Difficulty 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: False
Link To: Metabolism: Energy and Life
Difficulty Level: Medium
46. Assembling an ATP molecule is an endothermic process in the cell.
Ans: True
Link To: Metabolism: Energy and Life
Difficulty Level: Medium
47. Receptor molecules in the cell membrane are open gates to all molecules with hydrogen
bonds.
Ans: False
Link 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 (manufacture
of 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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Chapter 21
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 Life
Difficulty 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 + energy
Link To: Metabolism: Energy and Life
Difficulty 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 Life
Difficulty 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 Cells
Difficulty Level: Medium
53. Compare and contrast eukaryotes and prokaryotes.
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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 influence
the 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 Cells
Difficulty 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 Division
Difficulty 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
of fermentation is lactic acid, which causes the stiffness as it accumulates in the cells. When the
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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 Life
Difficulty 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 Life
Difficulty 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 Life
Difficulty 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 Cells
Difficulty 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 Life
Difficulty Level: Hard
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Chapter 21
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 Life
Difficulty 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 Division
Difficulty 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 Life
Difficulty 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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Chapter 21
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 Division
Difficulty Level: Hard
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