1.
The advantage of light microscopy over electron microscopy is that
A) light microscopy provides for higher magnification than electron microscopy.
B) light microscopy provides for higher resolving power than electron microscopy.
C) light microscopy allows one to view dynamic processes in living cells.
D) A and B
E) B and C
2.
A primary objective of cell fractionation is to
A) view the structure of cell membranes.
B) identify the enzymes outside the organelles.
C) determine the size of various organelles.
D) separate the major organelles so that their particular functions can be determined.
E) crack the cell wall so the cytoplasmic contents can be released.
3.
In the fractionation of homogenized cells using centrifugation, the primary factor that determines whether a specific cellular
component ends up in the supernatant or the pellet is
A) the relative solubility of the component.
B) the size and weight of the component.
C) the percentage of carbohydrates in the component.
D) the number of enzymes in the fraction.
E) the presence or absence of lipids in the component.
4.
The volume enclosed by the plasma membrane of plant cells is often much larger than the corresponding volume in animal
cells. The most reasonable explanation for this observation is that
A) plant cells are capable of having a much higher surface-to-volume ratio than animal cells.
B) plant cells have a much more highly convoluted (folded) plasma membrane than animal cells.
C) plant cells contain a large vacuole that reduces the volume of the cytoplasm.
D) animal cells are more spherical, while plant cells are elongated.
E) the basic functions of plant cells are very different from those of animal cells.
5.
The nuclear lamina is an array of filaments on the inner side of the nuclear membrane. If a method were found that could
cause the lamina to fall into disarray, what would you expect to be the most likely consequence?
A) the loss of all nuclear function
B) the inability of the cell to withstand enzymatic digestion
C) a change in the shape of the nucleus
D) failure of chromosomes to carry genetic information
E) inability of the nucleus to keep out destructive chemicals
6.
Under which of the following conditions would you expect to find a cell with a predominance of free ribosomes?
A) a cell that is secreting proteins
B) a cell that is producing cytoplasmic enzymes
C) a cell that is constructing its cell wall or extracellular matrix
D) a cell that is digesting food particles
E) a cell that is enlarging its vacuole
7.
Which type of organelle is primarily involved in the synthesis of oils, phospholipids, and steroids?
A) ribosome
B) lysosome
C) smooth endoplasmic reticulum
D) mitochondrion
E) contractile vacuole
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8.
The Golgi apparatus has a polarity or sidedness to its structure and function. Which of the following statements correctly
describes this polarity?
A) Transport vesicles fuse with one side of the Golgi and leave from the opposite side.
B) Proteins in the membrane of the Golgi may be sorted and modified as they move from one side of the Golgi to the other.
C) Lipids in the membrane of the Golgi may be sorted and modified as they move from one side of the Golgi to the other.
D) Soluble proteins in the cisternae (interior) of the Golgi may be sorted and modified as they move from one side of the Golgi to the
other.
E) All of the above correctly describe polar characteristics of the Golgi function.
9.
Tay-Sachs disease is a human genetic abnormality that results in cells accumulating and becoming clogged with very large
and complex lipids. Which cellular organelle must be involved in this condition?
A) the endoplasmic reticulum
B) the Golgi apparatus
C) the lysosome
D) mitochondria
E) membrane-bound ribosomes
10. The liver is involved in detoxification of many poisons and drugs. Which of the following structures is primarily involved in
this process and therefore abundant in liver cells?
A) rough ER
B) smooth ER
C) Golgi apparatus
D) Nuclear envelope
E) Transport vesicles
11. Organelles other than the nucleus that contain DNA include
A) ribosomes.
B) mitochondria.
C) chloroplasts.
D) B and C only
E) A, B, and C
12. The chemical reactions involved in respiration are virtually identical between prokaryotic and eukaryotic cells. In eukaryotic
cells, ATP is synthesized primarily on the inner membrane of the mitochondria. Where are the corresponding reactions likely
to occur in prokaryotic respiration?
A) in the cytoplasm
B) on the inner mitochondrial membrane
C) on the endoplasmic reticulum
D) on the inner plasma membrane
E) on the inner nuclear envelope
13. A biologist ground up some plant leaf cells and then centrifuged the mixture to fractionate the organelles. Organelles in one
of the heavier fractions could produce ATP in the light, while organelles in the lighter fraction could produce ATP in the
dark. The heavier and lighter fractions are most likely to contain, respectively,
A) mitochondria and chloroplasts.
B) chloroplasts and peroxisomes.
C) peroxisomes and chloroplasts.
D) chloroplasts and mitochondria.
E) mitochondria and peroxisomes.
14. A cell has the following molecules and structures: enzymes, DNA, ribosomes, plasma membrane, and mitochondria. It could
be a cell from
A) a bacterium.
B) an animal, but not a plant.
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C) a plant, but not an animal.
D) a plant or an animal.
E) any kind of organism.
15. The peroxisome gets its name from its interaction with hydrogen peroxide. If a liver cell is detoxifying alcohol and some
other poisons, it does so by removal of hydrogen from the molecules. What, then, do the enzymes of the peroxisome do?
A) combine the hydrogen with ATP
B) use the hydrogen to break down hydrogen peroxide
C) transfer the harmful substances to the mitochondria
D) transfer the hydrogens to oxygen molecules
16. Motor proteins provide for molecular motion in cells by interacting with what types of cellular structures?
A) sites of energy production in cellular respiration
B) membrane proteins
C) ribosomes
D) cytoskeletons
E) cellulose fibers in the cell wall
17. Centrioles, cilia, flagella, and basal bodies have remarkably similar structural elements and arrangements. This leads us to
which of the following as a probable hypothesis?
A) Disruption of one of these types of structure should necessarily disrupt each of the others as well.
B) Loss of basal bodies should lead to loss of all cilia, flagella, and centrioles.
C) Motor proteins such as dynein must have evolved before any of these four kinds of structure.
D) Evolution of motility, of cells or of parts of cells, must have occurred only once.
E) Natural selection for motility must select for microtubular arrays in circular patterns.
18. Microfilaments are well known for their role in which of the following?
A) ameboid movement
B) formation of cleavage furrows
C) contracting of muscle cells
D) A and B only
E) A, B, and C
19. Which of the following statements about the cytoskeleton is true?
A) The dynamic aspect of cytoskeletal function is made possible by the assembly and disassembly of a large number of complex
proteins into larger aggregates.
B) Microfilaments are structurally rigid and resist compression, while microtubules resist tension (stretching).
C) Movement of cilia and flagella is the result of motor proteins causing microtubules to move relative to each other.
D) Chemicals that block the assembly of the cytoskeleton would cause little effect on the cell's metabolism
E) Transport vesicles among the membranes of the endomembrane system produce the cytoskeleton.
20. All of the following serve an important role in determining or maintaining the structure of plant cells. Which of the following
are distinct from the others in their composition?
A) microtubules
B) microfilaments
C) plant cell walls
D) intermediate filaments
E) nuclear lamina
21. When a potassium ion (K+) moves from the soil into the vacuole of a cell on the surface of a root, it must pass through
several cellular structures. Which of the following correctly describes the order in which these structures will be encountered
by the ion?
A) plasma membrane  primary cell wall  cytoplasm  tonoplast
B) secondary cell wall  plasma membrane  primary cell wall  cytoplasm  tonoplast
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C) primary cell wall  plasma membrane  cytoplasm  tonoplast
D) primary cell wall  plasma membrane  tonoplast  cytoplasm  vacuole
E) tonoplast  primary cell wall  plasma membrane  cytoplasm
22. The extracellular matrix is thought to participate in the regulation of animal cell behavior by communicating information
from the outside to the inside of the cell via which of the following?
A) gap junctions
B) the nucleus
C) DNA and RNA
D) integrins
E) plasmodesmata
23. Plasmodesmata in plant cells are most similar in function to which of the following structures in animal cells?
A) peroxisomes
B) desmosomes
C) gap junctions
D) extracellular matrix
E) tight junctions
24. Which of the following makes it necessary for animal cells, although they have no cell walls, to have intercellular junctions?
A) Cell membranes do not distinguish the types of ions and molecules passing through them.
B) Large molecules, especially proteins, do not readily get through one, much less two adjacent cell membranes.
C) Cell-to-cell communication requires physical attachment of one cell to another.
D) Maintenance of connective tissue shape requires cells to adhere to one another.
E) The relative shapelessness of animal cells requires a mechanism for keeping the cells aligned.
25. Recent evidence shows that the extracellular matrix can take part in regulating the expression of genes. A likely possibility
for this might be which of the following?
A) Mechanical signals of the ECM can alter the cytoskeleton, which can alter intracellular signaling.
B) Intracellular signals might cause changes in the fibronectin binding to the cell surface.
C) Orientation of microfilaments to the ECM can change the gene activity.
D) Fibronectin binds to integrins built into the plasma membrane.
E) Proteoglycans in the ECM become large enough in aggregate to force genetic alteration.
26. Which of the following types of molecules are the major structural components of the cell membrane?
A) phospholipids and cellulose
B) nucleic acids and proteins
C) phospholipids and proteins
D) proteins and cellulose
E) glycoproteins and cholesterol
27. The presence of cholesterol in the plasma membranes of some animals
A) enables the membrane to stay fluid more easily when cell temperature drops.
B) enables the animal to remove hydrogen atoms from saturated phospholipids.
C) enables the animal to add hydrogen atoms to unsaturated phospholipids.
D) makes the membrane less flexible, allowing it to sustain greater pressure from within the cell.
E) makes the animal more susceptible to circulatory disorders.
28. Which of the following is one of the ways that the membranes of winter wheat are able to remain fluid when it is extremely
cold?
A) by increasing the percentage of unsaturated phospholipids in the membrane
B) by increasing the percentage of cholesterol molecules in the membrane
C) by decreasing the number of hydrophobic proteins in the membrane
D) by co-transport of glucose and hydrogen
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E) by using active transport
29. In order for a protein to be an integral membrane protein it would have to be which of the following?
A) hydrophilic
B) hydrophobic
C) amphipathic
D) completely covered with phospholipids
E) exposed on only one surface of the membrane
30. Of the following functions, which is most important for the glycoproteins and glycolipids of animal cell membranes?
A) facilitated diffusion of molecules down their concentration gradients
B) active transport of molecules against their concentration gradients
C) maintaining the integrity of a fluid mosaic membrane
D) maintaining membrane fluidity at low temperatures
E) a cell's ability to distinguish one type of neighboring cell from another
31. Which of these are attached to the extracellular matrix?
A) transmembrane proteins
B) integral proteins
C) peripheral proteins
D) integrins
E) glycoproteins
32. The formulation of a model for a structure or for a process serves which of the following purposes?
A) It asks a scientific question.
B) It functions as a testable hypothesis.
C) It records observations.
D) It serves as a data point among results.
E) It can only be arrived at after years of experimentation.
33. What kinds of molecules pass through a cell membrane most easily?
A) large and hydrophobic
B) small and hydrophobic
C) large polar
D) ionic
E) monosaccharides such as glucose
34. Which of the following is a characteristic feature of a carrier protein in a plasma membrane?
A) It is a peripheral membrane protein.
B) It exhibits specificity for a particular type of molecule.
C) It requires the expenditure of cellular energy to function.
D) It works against diffusion.
E) It has few, if any, hydrophobic amino acids.
35. Which of the following would likely move through the lipid bilayer of a plasma membrane most rapidly?
A) CO2
B) an amino acid
C) glucose
D) K+
E) starch
36. Water passes quickly through cell membranes because
A) the bilayer is hydrophilic.
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B) water movement is tied to ATP hydrolysis.
C) it is a small, polar, charged molecule.
D) it moves through aquaporins in the membrane.
The following information should be used to answer the following questions.
37. A patient has had a serious accident and lost a lot of blood. In an attempt to replenish body fluids, distilled water, equal to the
volume of blood lost, is transferred directly into one of his veins. What will be the most probable result of this transfusion?
A) It will have no unfavorable effect as long as the water is free of viruses and bacteria.
B) The patient's red blood cells will shrivel up because the blood fluid is hypotonic compared to the cells.
C) The patient's red blood cells will swell because the blood fluid is hypotonic compared to the cells.
D) The patient's red blood cells will shrivel up because the blood fluid is hypertonic compared to the cells.
E) The patient's red blood cells will burst because the blood fluid is hypertonic compared to the cells.
Refer to Figure 7.3 to answer the following questions.
The solutions in the arms of a U-tube are separated at the bottom of the tube by a selectively permeable membrane. The membrane is
permeable to sodium chloride but not to glucose. Side A is filled with a solution of 0.4 M glucose and 0.5 M sodium chloride (NaCl),
and side B is filled with a solution containing 0.8 M glucose and 0.4 M sodium chloride. Initially, the volume in both arms is the same.
Figure 7.3
38. At the beginning of the experiment,
A) side A is hypertonic to side B.
B) side A is hypotonic to side B.
C) side A is isotonic to side B.
D) side A is hypertonic to side B with respect to glucose.
E) side A is hypotonic to side B with respect to sodium chloride.
39. If you examine side A after 3 days, you should find
A) a decrease in the concentration of NaCl and glucose and an increase in the water level.
B) a decrease in the concentration of NaCl, an increase in water level, and no change in the concentration of glucose.
C) no net change in the system.
D) a decrease in the concentration of NaCl and a decrease in the water level.
E) no change in the concentration of NaCl and glucose and an increase in the water level.
40. Which of the following statements correctly describes the normal tonicity conditions for typical plant and animal cells?
A) The animal cell is in a hypotonic solution, and the plant cell is in an isotonic solution.
B) The animal cell is in an isotonic solution, and the plant cell is in a hypertonic solution.
C) The animal cell is in a hypertonic solution, and the plant cell is in an isotonic solution.
D) The animal cell is in an isotonic solution, and the plant cell is in a hypotonic solution.
E) The animal cell is in a hypertonic solution, and the plant cell is in a hypotonic solution.
Read the following information and refer to Figure 7.4 to answer the following questions.
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Five dialysis bags, constructed from a semi-permeable membrane that is impermeable to sucrose, were filled with various
concentrations of sucrose and then placed in separate beakers containing an initial concentration of 0.6 M sucrose solution. At 10minute intervals, the bags were massed (weighed) and the percent change in mass of each bag was graphed.
Figure 7.4
41. Which line represents the bag that contained a solution isotonic to the 0.6 molar solution at the beginning of the experiment?
Answer: C
42. Which line represents the bag with the highest initial concentration of sucrose?
Answer: A
43. You are working on a team that is designing a new drug. In order for this drug to work, it must enter the cytoplasm of specific
target cells. Which of the following would be a factor that determines whether the molecule enters the cell?
A) blood or tissue type of the patient
B) non-polarity of the drug molecule
C) lack of charge on the drug molecule
D) similarity of the drug molecule to other molecules transported by the target cells
E) lipid composition of the target cells' plasma membrane
44. In most cells, there are electrochemical gradients of many ions across the plasma membrane even though there are usually
only one or two electrogenic pumps present in the membrane. The gradients of the other ions are most likely accounted for by
A) cotransport proteins.
B) ion channels.
C) carrier proteins.
D) B and C only
E) A, B, and C
45. Ions diffuse across membranes down their
A) chemical gradients.
B) concentration gradients.
C) electrical gradients.
D) electrochemical gradients.
E) A and B are correct.
45. What mechanisms do plants use to load sucrose produced by photosynthesis into specialized cells in the veins of leaves?
A) an electrogenic pump
B) a proton pump
C) a contransport protein
D) A and C only
E) A, B, and C
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For the following questions, match the labeled component of the cell membrane (Figure 7.1) with its description.
47. cholesterol
Answer: E
48. fiber of the extracellular matrix
Answer: A
49. microfilament of the cytoskeleton
Answer: C
50. glycolipid
Answer: B
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