Cell and Cell Functions Test Questions
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____ 1. Which of the following organisms do not have cell walls?
a. plants c. bacteria
b. fungi d. animals
____ 2. Which of the following is NOT true of plasma membranes?
a. Folded membranes increase surface area for efficiency.
b. Folded membranes do not form compartments in the cell.
c. Endoplasmic reticulum is made up of folded membranes.
d. Ribosomes are sometimes attached to folded membranes.
____ 3. Folded membranes are an advantage to a cell because _____.
a. cell processes can be more efficient
b. the membranes provide a large surface area
c. the membranes form interconnected compartments
d. all of these
____ 4. Who concluded that all plants are made of living cells?
a. Virchow c. Schwann
b. Hooke d. Schleiden
____ 5. All living things are made up of _____.
a. cells c. wastes
b. cork d. cellulose
____ 6. What do electron microscopes use to focus and magnify an image?
a. glass lenses c. electron beams
b. X rays d. light
____ 7. Each of the following is a main idea of the cell theory except _____.
a. all organisms are composed of cells
b. the cell is the basic unit of organization of organisms
c. all cells are similar in structure and function
d. all cells come from preexisting cells
____ 8. The scientist who first described living cells as seen through a simple microscope was _____.
a. van Leeuwenhoek c. Hooke
b. Schleiden d. Schwann
____ 9. One advantage of electron microscopes over light microscopes is their _____.
a. size c. two-dimensional image
b. higher magnification d. use of live specimens
____ 10. If a cell contains a nucleus, it must be a(n) _____.
a. plant cell c. animal cell
b. eukaryotic cell d. prokaryotic cell
____ 11. In a chloroplast, the stacks of membranous sacs are called _____.
a. stroma c. plastids
b. grana d. thylakoid membrane
____ 12. Because cells have a watery environment both inside and outside, the polar ends of the phospholipids in the
plasma membrane form ____ layers
a. several c. double
b. mosaic d. single
____ 13. The fluid mosaic model describes a structure with ____.
a. polar layers on the outside and nonpolar layer on the inside
b. nonpolar layers on the outside and a polar layer on the inside
c. polar layers on both inside and outside
d. nonpolar layers on both inside and outside
____ 14. Because the phospholipid molecules and some proteins are free to move, the plasma membrane is said to be a
____.
a. bilayer c. fluid mosaic
b. solid d. fatty acid
____ 15. Which of the following might be a result of a disease that causes a thickened plasma membrane?
a. increased movement of molecules entering the cell
b. decreased movement of molecules within the cell
c. decreased movement of molecules entering the cell
d. increased movement of molecules leaving the cell
____ 16. A cell's contents would be the same as its surrounds, were it not for ____.
a. plasmolysis c. phagocytosis
b. selective permeability d. dynamic equilibrium
____ 17. A plasma membrane is made up of a(n) _____.
a. cholesterol layer c. lipid bilayer
b. enzyme bilayer d. protein layer
____ 18. Which is not a way that Figure 7-2 is a model of cellular theory?
Figure 7-2
a. bricks are small units in a building
b. bricks are solid
c. there are many bricks in a building
d. bricks are organized to make a larger unit
Figure 7-3
____ 19. What is the approximate size of A in Figure 7-3?
a. 400 m c. 700 m
b. 500 m d. 1000 m
____ 20. What is the approximate size of B in figure 7-3?
a. 400 m c. 700 m
b. 500 m d. 1000 m
____ 21. What would be the best way to estimate the size of C in Figure 7-3?
a. increase magnification c. estimate by what you can see
b. decrease magnification d. assume it is 2000 m
Figure 7-4
____ 22. What would happen to the structure in Figure 7-4 if part D is completely removed?
a. it would become solid c. it would have holes in it
b. it would disintegrate d. it would collapse in on itself
____ 23. What structure is analogous to a sewage system?
a. A c. C
b. B d. D
____ 24. Where are you least likely to find water in the structure shown in Figure 7-4
a. A c. C
b. B d. E
____ 25. Which of the following pictures in Figure 7-5 most likely approximate the motion phospholipids make in a
plasma membrane?
Figure 7-5
a. A c. C
b. B d. D
Figure 7-6
____ 26. Which structure in Figure 7-6 is the cell control center?
a. A c. I
b. G d. M
____ 27. Which structure in Figure 7-6 maintains homeostasis?
a. B c. H
b. D d. L
____ 28. Which structure in Figure 7-6 is responsible for chemical reactions?
a. A c. J
b. E d. L
____ 29. Which structure in Figure 7-6 transforms energy?
a. C c. J
b. G d. K
____ 30. Which structure in Figure 7-6 sorts and transports?
a. B c. I
b. G d. M
____ 31. Which parts of Figure 7-6 are in a prokaryotic cell?
a. D and M c. C and J
b. A and K d. G and L
____ 32. A cell contains the structure shown in Figure 7-7. What other cell structure that is not found in all eukaryotic
cells is likely to be found in this cell?
Figure 7-7
a. mitochondria c. cell wall
b. ribosomes d. plasma membrane
____ 33. Water moves into a cell placed in a(n) _____ solution.
a. osmotic c. hypotonic
b. hypertonic d. isotonic
____ 34. Water moves out of a cell if the cell is placed in a(n) _____ solution.
a. hypertonic c. hypotonic
b. isotonic d. passive
____ 35. If cells are placed in a strong sugar solution, water will _____.
a. pass from the sugar solution to the cells
b. pass from the cells to the sugar solution
c. stay in the cell
d. pass back and forth
____ 36. A cell moves particles from a region of lesser concentration to a region of greater concentration by _____.
a. facilitated diffusion c. osmosis
b. passive transport d. active transport
____ 37. If a cell is placed in salt water, water leaves the cell by _____.
a. osmosis c. active transport
b. diffusion d. phagocytosis
____ 38. Which of the following is not a form of passive transport?
a. facilitated diffusion c. facilitated diffusion
b. endocytosis d. osmosis
____ 39. The structure most responsible for maintaining cell homeostasis is the _____.
a. cytoplasm c. cell wall
b. mitochondrion d. plasma membrane
____ 40. The causes of cancer may include which of the following?
a. environmental influences c. viruses
b. UV radiation d. all of the above
____ 41. A gene is a segment of DNA that controls the production of _____.
a. carbohydrates c. centromeres
b. microtubules d. proteins
____ 42. Which of the following monitors a cell's progress from phase to phase during the cell cycle?
a. a series of enzymes c. lipid molecules
b. microtubules d. protein molecules
____ 43. If the sides of a cell double in length, its volume increases by _____ times.
a. two c. six
b. four d. eight
____ 44. If the sides of a cell double in length, its surface area becomes _____ times as large.
a. two c. six
b. four d. eight
____ 45. Which of the following explains why a cell's size is limited?
a. Volume increases faster than surface area.
b. Surface area increases faster than volume.
c. Homeostasis is disrupted by a cell that is too large.
d. both a and c
____ 46. As a cell grows, its _____ increases more than its _____.
a. length, volume c. volume, surface area
b. width, surface area d. none of these
____ 47. Among the following, the term that includes the others is _____.
a. interphase c. mitosis
b. nuclear division d. cell cycle
____ 48. By the end of prophase, each of the following has occurred except _____.
a. tighter coiling of the chromosomes
b. breaking down of the nuclear envelope
c. disappearing of the nucleolus
d. lining up of chromosomes in the cell
____ 49. Unlike plant cells, animal cells contain _____.
a. cell walls c. nucleoli
b. centrioles d. spindles
____ 50. The longest phase of the cell cycle is _____.
a. prophase c. metaphase
b. interphase d. mitosis
____ 51. A chromatid is attached to a spindle fiber by the _____.
a. nucleolus c. centromere
b. deep furrow d. centriole
____ 52. Which of the following structures is the most complex?
a. cell c. organ
b. organ system d. tissue
____ 53. Which conditions shown in Figure 8-4 might cause a cell to burst?
Figure 8-4
a. A c. C
b. B d. D
____ 54. What cell process is responsible for the effect shown in Figure 8-5?
Figure 8-5
a. active transport c. facilitated diffusion
b. passive transport d. osmosis
____ 55. The chromosomes shown in Figure 8-6 are in which state of mitosis?
Figure 8-6
a. prophase c. anaphase
b. metaphase d. telophase
____ 56. What level of organization is shown in Figure 8-7?
a. tissue c. organ system
b. organ d. organism
Figure 8-8
____ 57. Which of the cells depicted in the line graph in Figure 8-8 are most likely cancerous?
a. A c. C
b. B d. D
____ 58. If cancer is present, what is the likely explanation for what happened to cells B and D?
a. they thrived with the cancerous cells
b. they were harmed by radiation therapy
c. they died off on due to natural causes
d. they died off because the cancerous cells deprived them of nutrients
____ 59. The main energy-trapping molecule in plants is _____.
a. chloroplast c. stroma
b. chlorophyll d. carotenoids
____ 60. Energy from sunlight is trapped by chlorophyll located in the _____.
a. citric acid cycle c. electron transport chain
b. mitochondria d. thylakoid membranes
____ 61. Chlorophyll traps _____ from sunlight.
a. oxygen c. hydrogen
b. energy d. glucose
____ 62. A green pigment that traps energy from sunlight is _____.
a. carotenoid c. chlorophyll
b. ATP d. thylakoid membranes
____ 63. Which sugar is a part of adenosine diphosphate?
a. adenine c. glucose
b. ribose d. glycogen
____ 64. Energy is released from ATP when the bond is broken between _____.
a. two phosphate groups c. ribose and a phosphate group
b. adenine and ribose d. adenine and a phosphate group
____ 65. Organisms need a way of storing energy because _____.
a. a cell can't always immediately use all the energy it gets
b. an organism often has times when no energy is used
c. a cell can release only stored energy
d. a cell cannot create energy and must get it from elsewhere in the organism
____ 66. In order to move molecules in your kidneys, your body needs _____.
a. energy c. cold
b. sunlight d. heat
____ 67. In the complete process of photosynthesis, the _____.
a. Calvin cycle yields CO2
b. light reactions release oxygen
c. Calvin cycle breaks down H2O
d. light reactions produce NADP+ from NADPH + H+
____ 68. In glycolysis, _____ molecules of ATP are used in the first step, and _____ molecules of ATP are produced in
the second step.
a. four, two c. two, two
b. two, four d. four, four
____ 69. In respiration, the final electron acceptor in the electron transport chain is _____.
a. oxygen c. hydrogen ions
b. ATP d. H2O
____ 70. Kidneys use energy to move molecules and ions in order to keep the blood chemically balanced. This process
is an example of cells using energy to _____.
a. carry on chemosynthesis c. control body temperature
b. transmit impulses d. maintain homeostasis
____ 71. Which of the following equations best represents photosynthesis?
a. C + O2 + H2O CO2 + HOH c. 6C + 6H2O C6H12O6
b. 6CO2 + 6H2O C6H12O6 + 6O2 d. C6H12O6 6CO2 + 6H2O
____ 72. Leaves appear green because the green portion of the light that strikes them is _____.
a. changed to heat c. destroyed
b. absorbed d. reflected
____ 73. Cells store energy when _____.
a. the third phosphate group breaks off from an ATP molecule
b. they break down sucrose to glucose and fructose
c. a third phosphate group is bonded to an ATP molecule
d. ions are released into the bloodstream
____ 74. The energy in glucose cannot be released by _____.
a. glycolysis c. respiration
b. burning d. photosynthesis
____ 75. Which of the following is not a part of adenosine diphosphate?
a. glucose c. ribose
b. adenine d. two phosphate groups
____ 76. Which of the diagrams in Figure 9-2 best show how energy is produced in a cell?
Figure 9-2
a. A c. C
b. B d. D
____ 77. Which of the processes shown in Figure 9-3 do not use a cell’s energy?
Figure 9-3
a. A c. C
b. B d. D
____ 78. What is the main purpose of the cycle shown in Figure 9-4?
Figure 9-4
a. sugar production c. production of ADP
b. destruction of CO2 d. production of NADP-
____ 79. In which types of organisms does the process shown in Figure 9-5 take place?
Figure 9-5
a. plants only c. neither plants nor animals
b. animals only d. both plants and animals
Completion
Complete each statement.
80. Cell structures that contain digestive enzymes are ____________________.
81. In a cell, the sites of protein synthesis are the ____________________.
82. The small, membrane-bound structures inside a cell are ____________________.
83. The movement of materials into and out of the cells is controlled by the ____________________.
84. An organism with a cell that lacks a true nucleus is a(n) ____________________.
85. In a cell, the breakdown of molecules in order to release energy occurs in the ____________________.
86. Short, hairlike projections used for locomotion are ____________________.
87. In plants, the structures that transform light energy into chemical energy are called ____________________.
88. The network of tiny rods and filaments that forms a framework for the cell is called the
____________________.
89. The pigment that gives plants their green color is ____________________.
90. The folded system of membranes that forms a network of interconnected compartments inside the cell is
called the _________________________.
91. In a cell, the tangles of long strands of DNA form the ____________________.
92. The functions of a eukaryotic cell are managed by the ____________________.
93. A structure outside the plasma membrane in some cells is the ____________________.
94. The structures that hold together sister chromatids are ____________________.
95. In a dividing cell, the football-shaped structure consisting of thin fibers is the ____________________.
96. The process by which nuclear material is divided equally between two new cells is ____________________.
97. The dark-staining structures that carry the genetic material are the ____________________.
98. The uncontrolled division of cells that results in a malignant growth is known as ____________________.
99. The two halves of a doubled chromosome structure are called ____________________.
100. The sequence of growth and division of a cell makes up the ____________________.
101. The phase of mitosis in which the sister chromatids separate from each other is ____________________.
102. Cells that work together to perform the same function are organized into ____________________.
103. A series of reactions in aerobic respiration that begins and ends with the same 6-carbon compound is the
____________________.
104. In photosynthesis, the series of reactions that synthesize simple sugars from carbon dioxide and hydrogen is
known as the ____________________.
105. The anaerobic process of splitting glucose to form pyruvic acid is called ____________________.
106. The splitting of water during photosynthesis is ____________________.
107. The passing of electrons along a series of molecules, releasing energy as they go, is known as a(n)
_________________________.
108. The process by which autotrophs use energy from sunlight to build carbohydrates is called
____________________.
109. The reactions in photosynthesis in which energy from the sun is converted to chemical energy are called
____________________.
Matching
Match each item with the correct statement below.
a. exocytosis d. isotonic solution
b. gene e. osmosis
c. diffusion f. hypertonic solution
____ 110. movement of particles from an area of higher concentration to one of lower concentration
____ 111. the concentration of dissolved substances outside the cell is higher than the concentration inside the cell
____ 112. the concentration of dissolved substances in the solution is the same as the concentration of dissolved
substances inside the cell
____ 113. a segment of DNA that controls the production of a protein
____ 114. diffusion of water molecules through a selectively permeable membrane
____ 115. release of wastes or cell products from inside to outside a cell
Short Answer
116. In plants, cells that transport water against the force of gravity are found to contain many more mitochondria
than do some other plant cells. What is the reason for this?
Figure 7-1
117. Figure 7-1 shows a light area with no surrounding membrane in the center of the cell. This area contains a
single large DNA molecule. Would scientists classify this cell as a prokaryote or a eukaryote? Explain.
118. Identify the structures labeled A, B, and C in Figure 7-1.
119. Folded membranes have important uses in the cell. Discuss at least four of these uses.
120. The inner membrane of the mitochondria is folded many times. What advantage does this folding provide?
121. At one time people believed that organisms could be formed spontaneously from nonliving matter. Evaluate
this belief in light of the cell theory.
122. What is the difference between an electron microscope and a compound microscope?
123. Explain why scientists have only recently begun to understand how the cytoskeleton functions in the cell.
124. Based on what you know about cells, why are microscopes important to the study of cells?
125. Between which cell types is the difference greater--plant and animal cells or prokaryotic and eukaryotic cells?
Give reasons for your answer.
126. Many types of animal cells have a thin, flexible cell covering outside the plasma membrane. This cell
covering, called a glycocalyx, consists of complex carbohydrates bonded to the proteins and lipids in the
plasma membrane. How is the glycocalyx similar to the cell wall of a green plant? How is it different?
For many years, scientists thought of the nucleus as "a bag of chromatin floating in a sea of cytoplasm." Using
electron microscopes, scientists saw that the nucleus was much more complex. The nuclear envelope was two
layered and covered with pores.
Scientists began further research. Scientist S punched small holes in the nuclear envelope, allowing the
contents to pour out. He observed that the nucleus retained its spherical shape. From this, scientist S
hypothesized that the nucleus had some other structural framework, beyond the membrane itself. The next
experiment performed by scientist S revealed that the nucleus indeed had a fibrous protein framework, now
called the nuclear matrix.
Three other scientists repeated this experiment, but each changed one part of it. Scientist X used
detergents and salt to remove the nuclear contents. Scientist Y used chemicals, and scientist Z used enzymes.
All three observed that a nuclear matrix remained.
Further electron microscopy revealed that the chromatin strands were anchored to a fibrous layer that
lines the inner layer of the nuclear envelope.
127. Describe a procedure to determine whether the attachment of the chromatin to the nuclear envelope is
necessary for the chromatin to become chromosomes.
128. Why did scientists X, Y, and Z use different substances to remove the nuclear contents?
129. What was the variable in the experiments by scientists X, Y, and Z?
130. Why did scientists X, Y, and Z carry out their experiments?
131. What observation from scientist S's second experiment supported the original hypothesis?
132. What was the hypothesis of scientist S in his first experiment?
133. Why is it important that some proteins extend all the way through the bilayer of a plasma membrane?
In the 1890s, E. Overton performed experiments to determine the structure of the plasma membrane. After
many years and various procedures, he determined that large, uncharged molecules enter a cell at a rate
proportional to their solubility in lipids. This observation was the first indication that the plasma membrane is
probably made up of lipids. Many scientists began to pursue the question of how the lipids were arranged.
In 1925, two Dutch scientists determined that the area covered by the lipids from a single red blood cell is
twice the area of the surface of the cell. From this, they reasoned that the cell is covered by a double layer of
lipid molecules. Based on this work, various scientists hypothesized that the membrane was like a "fat
sandwich" with two outer layers of protein on the surface of the lipid layer.
None of the ideas seemed a satisfactory explanation until microscopic studies of membranes prepared by
a new technique of "freeze-fracture" revealed that the proteins are actually embedded in the lipid layer. In
1972, on the basis on these results and other evidence, two American scientists proposed the fluid-mosaic
model.
134. Why was it almost 50 years between the Dutch scientists' research and the proposal of a fluid mosaic model?
135. What model of the plasma membrane was based on the Dutch scientists' results?
136. What inference did the Dutch scientists make to reach their conclusion?
137. What conclusion did the Dutch scientists reach?
138. The result of one experiment often leads to further experiments. How do Overton's experiments illustrate this
fact?
139. Is Overton's hypothesis stated in the discussion above? If so, what was it?
140. What was the problem that Overton was trying to solve with his experiment?
141. Compare and contrast the structure and function of channel proteins and carrier proteins.
A selectively permeable membrane is stretched across a funnel filled with starch solution. Figure 8-1 shows
the funnel inverted into a beaker containing an iodine solution. Starch molecules are too large to diffuse
across the membrane; iodine molecules are not. If iodine reacts with starch, the starch turns blue-black.
Suppose you observe the setup after several hours.
Figure 8-1
142. Does the level of the liquid rise, fall, or remain the same in the stem of the inverted funnel shown in Figure 8-
1? Why?
143. Referring to Figure 8-1, does the starch solution change color? Explain.
144. Referring to Figure 8-1, does the iodine solution change color? Explain.
145. Predict what would happen if a saltwater plant were placed in a freshwater aquarium.
146. Pickled foods are preserved with salt. How might a strong salt solution preserve cucumbers?
Figure 8-2
147. The graph in Figure 8-2 shows typical concentrations of several ions inside and outside an animal cell.
Concentrations of ions inside the cell are shown in gray, outside in black. Describe the process by which the
cell maintains differences in concentration of certain ions inside and outside the cell.
148. The graph in Figure 8-2 shows typical concentrations of several ions inside and outside an animal cell.
Concentrations of ions inside the cell are shown in gray, outside in black. If all available Na+ and Cl- ions
combine to form NaCl, do any excess Na+ or Cl- ions remain? If so, which?
149. The graph in Figure 8-2 shows typical concentrations of several ions inside and outside an animal cell.
Concentrations of ions inside the cell are shown in gray, outside in black. What is the approximate
concentration in mM of Mg2+ ions inside the cell?
150. The graph in Figure 8-2 shows typical concentrations of several ions inside and outside an animal cell.
Concentrations of ions inside the cell are shown in gray, outside in black. Which ions are in the lowest
concentration inside the animal cell?
151. The graph in Figure 8-2 shows typical concentrations of several ions inside and outside an animal cell.
Concentrations of ions inside the cell are shown in gray, outside in black. Which ions are in the greatest
concentration outside the animal cell?
152. The graph in Figure 8-2 shows typical concentrations of several ions inside and outside an animal cell.
Concentrations of ions inside the cell are shown in gray, outside in black. Compared to its surroundings, does
an animal cell contain a higher or lower concentration of potassium (K+) ions?
Figure 8-3
153. Sequence the six diagrams in Figure 8-3 in order from first to last, beginning with D.
154. Cells A and F of Figure 8-3 show an early and a late stage of the same phase of mitosis. What phase is it?
155. Which cell of Figure 8-3 is in metaphase?
156. In an animal cell undergoing mitosis, the spindle first appears as two asters, structures in which fibers radiate
out from each centriole. Would you expect to find asters in plant cells? Why or why not?
157. When prokaryotic bacterial cells undergo cell division, the single circular chromosome replicates to form a
second chromosome. This new chromosome, like the original, attaches to the plasma membrane. Next, the
plasma membrane pinches inward, and a cell wall forms across the middle of the cell to separate the two
chromosomes and form two daughter cells. How does cell division in bacteria differ from mitosis in
eukaryotes?
158. Cytokinesis is the division of the cytoplasm when a cell divides. In precisely which phase of the cell cycle
does cytokinesis occur?
159. In 1952, a prominent botany text described interphase as the first phase of mitosis. Now, more than 40 years
later, would scientists agree or disagree with that description? Explain.
The large size of many fruits and flowers is the result of polyploidy, a condition in which the nuclei of an
organism's cells contain extra sets of chromosomes. Polyploidy often occurs naturally, but it can also be
artificially induced by plant breeders. How have breeders been able to mimic a naturally occurring
phenomenon?
Researchers have determined that the chemical colchicine suppresses cell division by preventing the
formation of spindle fibers. Without these fibers, the sister chromatids cannot become properly oriented for
separation into individual nuclei. In effect, mitosis is stopped after prophase. However, the cell may continue
to make copies of its chromosomes. As a result, the nucleus of the cell contains multiple sets of
chromosomes.
Suppose a researcher wished to investigate how extra sets of chromosomes are produced. First, she
treated two onion roots with a colchicine solution and left two roots untreated. After a period of several days,
she placed thin slices from each root tip on separate slides, stained the specimens, and examined the slides
under a microscope at high power.
160. "Why does treating cells with colchicine prevent the formation of the spindle fibers?" Is this question the
statement of the problem or the conclusion of a further investigation? Explain.
161. If the researcher finds only cells in interphase and prophase in the slides of treated root tips, what might be her
interpretation?
162. How do you predict the slides of treated and untreated root tips will differ?
163. What was the variable in the investigation?
164. Which root tips were the controls? Which root tips were the experimentals?
165. What is the hypothesis the researcher investigated?
166. Based on your study of cells, argue for or against the following statement: "Cells in unicellular organisms are
more complex than cells in multicellular organisms."
167. Compare and contrast the terms photosynthesis and cellular respiration.
168. Compare and contrast the terms aerobic process and anaerobic process.
169. What do you think would happen to a plant's energy-trapping ability if suddenly the only pigment it contained
was chlorophyll? What is your reasoning?
170. How is ATP obtained from aerobic processes?
171. Predict what would happen if all the ATP production in living things suddenly ceased.
172. How is energy stored in ATP?
173. How does the storage of energy in ATP molecules benefit a cell?
174. If you run or ride a bicycle as fast as you can, your muscles may begin to feel weak and have a burning
sensation. Explain what is occurring that accounts for this muscle fatigue.
175. Explain what is meant by carbon fixation. During which stage of photosynthesis does this process take place?
176. In respiration, the steps following glycolysis depend upon whether oxygen is present. Explain.
177. Both the wine industry and the bread industry use the process of alcoholic fermentation. In what ways is the
use of the process by these industries similar? In what way do the uses differ?
178. Maintaining body temperature, transmitting nerve impulses, movement of cilia, and bioluminescence are
various activities of organisms. What requirement do these activities have in common? Why is ATP important
in each activity?
179. In an experiment to determine whether green plants take in CO2, a biologist filled a large beaker with
aquarium water to which she added bromothymol blue. She exhaled CO2 into the solution of bromothymol
blue to turn it yellow. Then she placed a sprig of Elodea into two test tubes. She left the third test tube without
Elodea to serve as a control. She added the yellow bromothymol solution to all three test tubes and placed a
stopper in each. Next, she placed all the test tubes in sunlight. After several hours in sunlight, the
bromothymol solution in the test tubes with the Elodea turned blue. The bromothymol solution in the control
remained yellow. What conclusion can be drawn from the observations? Explain.
Molecular Yield of ATP per Glucose Molecule
Reaction ATP Produced ATP Used
Glycolysis 4 2
Production of Acetyl-CoA 2
Citric acid cycle 2
Electron transport chain 34
Table 9-1
180. Refer to Table 9-1. The combination of glycolysis and fermentation yields a net gain of two ATP molecules.
How many molecules of ATP does fermentation yield? Explain.
181. What is the total net gain in ATP molecules per glucose molecule? Refer to Table 9-1.
182. Referring to Table 9-1, what is the net production of ATP molecules by each of the four reactions?
In 1803, Thomas Engelmann of Germany used a combination of filamentous alga and aerobic bacteria to
study the effect of various colors of the visible light spectrum on the rate of photosynthesis. He passed white
light through a prism in order to separate the light into the different colors of the spectrum; then he exposed
different segments of the alga to the various colors. He observed in which areas of the spectrum the greatest
number of bacteria appeared.
Figure 9-1
183. Did Engelmann's observations verify his hypothesis? Explain. Refer to Figure 9-1.
184. Describe one control Engelmann might have used. Refer to Figure 9-1.
185. What was the independent variable in this experiment? You may refer to Figure 9-1.
186. Based on Figure 9-1, what would Engelmann's conclusion be?
187. Why did Engelmann select aerobic rather than anaerobic bacteria? See Figure 9-1.
188. Referring to Figure 9-1, how was the observation about the amount of oxygen present related to Engelmann's
purpose?
189. Was determining where there was more oxygen the purpose of Engelmann's experiment? If not, state the
purpose. You may refer to Figure 9-1.