Workman: Pathophysiology for Advanced Practice, 1e 1
Test Bank
Chapter 1 Cellular Biology, Regulation, and Control Mechanisms
1. Which structure(s) is/are common feature(s) of all cells regardless of cellular function or
degree of maturity?
A. Cilia
B. Nuclear envelope
C. Plasma membranes
D. Smooth endoplasmic reticulum
Correct Answer: C
Rationale:
All human cells have a plasma membrane, although it may have other names in skeletal muscles
and neurons. Other features, such as a nucleus, rough and smooth endoplasmic reticulum,
mitochondria, and others, are not present in every cell type.
2. Why are most positive feedback mechanisms harmful if allowed to continue to function
indefinitely?
A. They amplify the effects of the initiating stimulus, increasing the undesirable response.
B. They require additional energy in the form of ATP and impair normal cellular uptake of
nutrients.
C. They misinterpret the input from homeostatic monitoring centers and delay control response
time.
D. They decrease the range of normal for most parameters, negating the need for homeostasis.
Correct Answer: A
Rationale:
Positive feedback mechanisms have the same responses as the initiating change, which results in
an amplification of the changed parameter, often increasing its rate of change. They can be
helpful in the very short run until other interventions or mechanisms can correct the initiating
problem. However, when they continue uncorrected, they lead to exhaustion of the system.
3. Which property of plasma membranes contributes to a cell’s longevity?
A. Unlimited size
B. Lack of covalent bonds
C. Hydrophilic outer surface
D. High concentration of lipids
Correct Answer: B
Rationale:
An important feature of plasma membranes is flexibility or fluidity, which allows cells to change
shape or “deform” without breaking. This feature is a result of the phospholipids composing
plasma membranes not having covalent bonds that would make them more rigid and more easily
Copyright © 2026
,Workman: Pathophysiology for Advanced Practice, 1e 2
Test Bank
ruptured when squeezing through small capillaries or when pressure is applied.
4. Which cell type is most likely to have the characteristic of polarity of orientation?
A. Red blood cell (erythrocyte)
B. Bronchial epithelium
C. Skeletal muscle
D. Lysosome
Correct Answer: B
Rationale:
Some cells are symmetrical on all sides, whereas others are asymmetrical and have polarity with
regard to orientation. This is related to differences in plasma membrane surface anatomy for a
cell’s specific function. For example, a respiratory epithelial cell has cilia on the luminal surface
and none on the apical surface that is in contact with the basement membrane. The same is true
about the epithelial lining of the intestinal tract with the luminal surfaces expressing villi.
5. Why does the lack of a nucleus in a mature erythrocyte fail to affect its function?
A. Function of these cells is independent of a constant oxygen supply.
B. Their membranes are more rigid than those of other cell types.
C. These cells no longer produce intracellular proteins.
D. Erythrocytes do not require energy for locomotion.
Correct Answer: C
Rationale:
Without a nucleus, a cell can neither divide nor produce proteins. In the case of mature
erythrocytes, all cell division and protein production, including hemoglobin, are performed at an
earlier, less mature stage. Thus, a mature erythrocyte is already equipped with everything it
needs for function (transport of oxygen, acting as a buffering system) and no longer needs a
nucleus.
6. What is the purpose of “chaperone” proteins?
A. Completing the degradation of intracellular debris
B. Transporting newly synthesized proteins for exocytosis
C. Adding a ligand to the plasma membrane for endocytosis
D. Ensuring the correct folding of newly synthesized proteins
Correct Answer: D
Rationale:
Newly synthesized protein strands are released into the lumen of the RER with their amino acids
in linear order. However, protein function is based on its final structure, which includes how it is
folded. In the smooth ER (SER), “chaperone” proteins serve as guides that help fold the new
protein into its correct conformation (shape) for final function.
Copyright © 2026
,Workman: Pathophysiology for Advanced Practice, 1e 3
Test Bank
7. Why are hydrolases confined to lysosomes?
A. The pH of lysosomes optimizes hydrolase activity.
B. They ensure degradation products are recycled appropriately.
C. They maintain a constant regeneration of transmembrane proteins.
D. Lysosomes have a direct connection to the nucleus where hydrolase is synthesized.
Correct Answer: A
Rationale:
The hydrolases within a lysosome are most effective at a pH of 4, which is the pH maintained
within lysosomes.
8. Why is it necessary to limit the intracellular presence of reactive oxygen species (ROS)?
A. High levels of ROS slow cellular locomotion.
B. ROS inhibit the activity of lysosomal catalase and hydrolase.
C. ROS contribute to an overly acidic intracellular environment.
D. They can damage/inhibit the function of intracellular components.
Correct Answer: D
Rationale:
Because ROS can also oxidize almost anything and cause oxidative stress and damage to other
organelles, tissues, and organs, preventing ROS from coming into contact with other normal cell
structures is critical.
9. Under normal physiologic conditions, which cell type has the highest concentration of
mitochondria?
A. Dermal skin cells
B. Intradermal skin cells
C. Mature erythrocytes
D. Skeletal muscle cells
Correct Answer: D
Rationale:
Mitochondria are the “powerhouses” for ATP production under aerobic conditions. They are
highly concentrated in tissues that are most metabolically active, such as skeletal muscle, heart
muscle, and liver cells, and they are only present in minimal or basal concentrations in less
metabolically active cells, such as skin cells and erythrocytes.
10. Why is glucose inhibited from entering most cells through simple passive diffusion even
though it is a nonpolar molecule?
A. The molecule expresses an overall negative charge.
B. Glucose is highly hydrophilic.
C. The molecule is too large for unaided diffusion.
Copyright © 2026
, Workman: Pathophysiology for Advanced Practice, 1e 4
Test Bank
D. Glucose is devoid of lipid-soluble components.
Correct Answer: C
Rationale:
Simple passive diffusion allows small, hydrophobic, uncharged (nonpolar) molecules to diffuse
across plasma membranes easily. Although glucose is a nonpolar molecule, it is composed of 24
molecules linked together covalently, making it too large to move across most plasma
membranes by simple diffusion.
11. Which factor regarding the generation of action potentials (AP) is true?
A. The speed of depolarization is determined by the number of Na+-K+ ATPase pumps present in
the membrane.
B. Action potentials can only be generated in cells that normally express a high degree of
polarity when the membrane is at rest.
C. Although an AP may be initiated at any area of an excitable membrane, propagation of the AP
is unidirectional within one cell.
D. Excessive amounts of extracellular calcium enhance the capacity of an excitable membrane to
generate an action potential.
Correct Answer: B
Rationale:
All cells have an ICF that is more negative than the ECF, with nonexcitable membranes having
an electrical resting membrane potential of between -5 and -10 mv, and the ICF is only slightly
more negative than the ECF. Cells with excitable membranes have a much greater charge
difference between the ICF and the ECF, usually between -70 and -85 mv, which is required to
generate an action potential that can be transmitted to other cells within the tissue.
12. In any excitable membrane, what is the trigger for opening of the potassium channels during
the process of depolarization?
A. Rising intracellular ATP concentration
B. Loss of intracellular fluid protein content
C. Increased flexibility of plasma membranes
D. Closure of the voltage-regulated sodium channels
Correct Answer: D
Rationale:
A stimulus for depolarization causes a small portion of the excitable membrane to be more
permeable to Na+, which allows Na+ to influx down its concentration gradient into the cell.
Movement of Na+ into the cell increases ICF positivity. When ICF positivity reaches threshold
level (about +55 mv), all voltage-gated Na+ channels along the plasma membrane open at the
same time, allowing Na+ to rapidly enter the cell until the Na+ concentrations in the ICF and the
ECF surrounding the cell are the same and depolarized with regard to Na+. At this time, the
voltage-regulated Na+ channels close. Closure of these channels triggers K+ channels to open,
allowing intracellular K+ molecules to rapidly leave the cell down its concentration gradient until
Copyright © 2026
Test Bank
Chapter 1 Cellular Biology, Regulation, and Control Mechanisms
1. Which structure(s) is/are common feature(s) of all cells regardless of cellular function or
degree of maturity?
A. Cilia
B. Nuclear envelope
C. Plasma membranes
D. Smooth endoplasmic reticulum
Correct Answer: C
Rationale:
All human cells have a plasma membrane, although it may have other names in skeletal muscles
and neurons. Other features, such as a nucleus, rough and smooth endoplasmic reticulum,
mitochondria, and others, are not present in every cell type.
2. Why are most positive feedback mechanisms harmful if allowed to continue to function
indefinitely?
A. They amplify the effects of the initiating stimulus, increasing the undesirable response.
B. They require additional energy in the form of ATP and impair normal cellular uptake of
nutrients.
C. They misinterpret the input from homeostatic monitoring centers and delay control response
time.
D. They decrease the range of normal for most parameters, negating the need for homeostasis.
Correct Answer: A
Rationale:
Positive feedback mechanisms have the same responses as the initiating change, which results in
an amplification of the changed parameter, often increasing its rate of change. They can be
helpful in the very short run until other interventions or mechanisms can correct the initiating
problem. However, when they continue uncorrected, they lead to exhaustion of the system.
3. Which property of plasma membranes contributes to a cell’s longevity?
A. Unlimited size
B. Lack of covalent bonds
C. Hydrophilic outer surface
D. High concentration of lipids
Correct Answer: B
Rationale:
An important feature of plasma membranes is flexibility or fluidity, which allows cells to change
shape or “deform” without breaking. This feature is a result of the phospholipids composing
plasma membranes not having covalent bonds that would make them more rigid and more easily
Copyright © 2026
,Workman: Pathophysiology for Advanced Practice, 1e 2
Test Bank
ruptured when squeezing through small capillaries or when pressure is applied.
4. Which cell type is most likely to have the characteristic of polarity of orientation?
A. Red blood cell (erythrocyte)
B. Bronchial epithelium
C. Skeletal muscle
D. Lysosome
Correct Answer: B
Rationale:
Some cells are symmetrical on all sides, whereas others are asymmetrical and have polarity with
regard to orientation. This is related to differences in plasma membrane surface anatomy for a
cell’s specific function. For example, a respiratory epithelial cell has cilia on the luminal surface
and none on the apical surface that is in contact with the basement membrane. The same is true
about the epithelial lining of the intestinal tract with the luminal surfaces expressing villi.
5. Why does the lack of a nucleus in a mature erythrocyte fail to affect its function?
A. Function of these cells is independent of a constant oxygen supply.
B. Their membranes are more rigid than those of other cell types.
C. These cells no longer produce intracellular proteins.
D. Erythrocytes do not require energy for locomotion.
Correct Answer: C
Rationale:
Without a nucleus, a cell can neither divide nor produce proteins. In the case of mature
erythrocytes, all cell division and protein production, including hemoglobin, are performed at an
earlier, less mature stage. Thus, a mature erythrocyte is already equipped with everything it
needs for function (transport of oxygen, acting as a buffering system) and no longer needs a
nucleus.
6. What is the purpose of “chaperone” proteins?
A. Completing the degradation of intracellular debris
B. Transporting newly synthesized proteins for exocytosis
C. Adding a ligand to the plasma membrane for endocytosis
D. Ensuring the correct folding of newly synthesized proteins
Correct Answer: D
Rationale:
Newly synthesized protein strands are released into the lumen of the RER with their amino acids
in linear order. However, protein function is based on its final structure, which includes how it is
folded. In the smooth ER (SER), “chaperone” proteins serve as guides that help fold the new
protein into its correct conformation (shape) for final function.
Copyright © 2026
,Workman: Pathophysiology for Advanced Practice, 1e 3
Test Bank
7. Why are hydrolases confined to lysosomes?
A. The pH of lysosomes optimizes hydrolase activity.
B. They ensure degradation products are recycled appropriately.
C. They maintain a constant regeneration of transmembrane proteins.
D. Lysosomes have a direct connection to the nucleus where hydrolase is synthesized.
Correct Answer: A
Rationale:
The hydrolases within a lysosome are most effective at a pH of 4, which is the pH maintained
within lysosomes.
8. Why is it necessary to limit the intracellular presence of reactive oxygen species (ROS)?
A. High levels of ROS slow cellular locomotion.
B. ROS inhibit the activity of lysosomal catalase and hydrolase.
C. ROS contribute to an overly acidic intracellular environment.
D. They can damage/inhibit the function of intracellular components.
Correct Answer: D
Rationale:
Because ROS can also oxidize almost anything and cause oxidative stress and damage to other
organelles, tissues, and organs, preventing ROS from coming into contact with other normal cell
structures is critical.
9. Under normal physiologic conditions, which cell type has the highest concentration of
mitochondria?
A. Dermal skin cells
B. Intradermal skin cells
C. Mature erythrocytes
D. Skeletal muscle cells
Correct Answer: D
Rationale:
Mitochondria are the “powerhouses” for ATP production under aerobic conditions. They are
highly concentrated in tissues that are most metabolically active, such as skeletal muscle, heart
muscle, and liver cells, and they are only present in minimal or basal concentrations in less
metabolically active cells, such as skin cells and erythrocytes.
10. Why is glucose inhibited from entering most cells through simple passive diffusion even
though it is a nonpolar molecule?
A. The molecule expresses an overall negative charge.
B. Glucose is highly hydrophilic.
C. The molecule is too large for unaided diffusion.
Copyright © 2026
, Workman: Pathophysiology for Advanced Practice, 1e 4
Test Bank
D. Glucose is devoid of lipid-soluble components.
Correct Answer: C
Rationale:
Simple passive diffusion allows small, hydrophobic, uncharged (nonpolar) molecules to diffuse
across plasma membranes easily. Although glucose is a nonpolar molecule, it is composed of 24
molecules linked together covalently, making it too large to move across most plasma
membranes by simple diffusion.
11. Which factor regarding the generation of action potentials (AP) is true?
A. The speed of depolarization is determined by the number of Na+-K+ ATPase pumps present in
the membrane.
B. Action potentials can only be generated in cells that normally express a high degree of
polarity when the membrane is at rest.
C. Although an AP may be initiated at any area of an excitable membrane, propagation of the AP
is unidirectional within one cell.
D. Excessive amounts of extracellular calcium enhance the capacity of an excitable membrane to
generate an action potential.
Correct Answer: B
Rationale:
All cells have an ICF that is more negative than the ECF, with nonexcitable membranes having
an electrical resting membrane potential of between -5 and -10 mv, and the ICF is only slightly
more negative than the ECF. Cells with excitable membranes have a much greater charge
difference between the ICF and the ECF, usually between -70 and -85 mv, which is required to
generate an action potential that can be transmitted to other cells within the tissue.
12. In any excitable membrane, what is the trigger for opening of the potassium channels during
the process of depolarization?
A. Rising intracellular ATP concentration
B. Loss of intracellular fluid protein content
C. Increased flexibility of plasma membranes
D. Closure of the voltage-regulated sodium channels
Correct Answer: D
Rationale:
A stimulus for depolarization causes a small portion of the excitable membrane to be more
permeable to Na+, which allows Na+ to influx down its concentration gradient into the cell.
Movement of Na+ into the cell increases ICF positivity. When ICF positivity reaches threshold
level (about +55 mv), all voltage-gated Na+ channels along the plasma membrane open at the
same time, allowing Na+ to rapidly enter the cell until the Na+ concentrations in the ICF and the
ECF surrounding the cell are the same and depolarized with regard to Na+. At this time, the
voltage-regulated Na+ channels close. Closure of these channels triggers K+ channels to open,
allowing intracellular K+ molecules to rapidly leave the cell down its concentration gradient until
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