WGU D236 Pathophysiology | 80 Practice
Questions, Correct Answers & Rationales |
Comprehensive Exam Review 2026
Question 1
A patient with chronic gastroesophageal reflux disease develops
columnar epithelium in the distal esophagus. This cellular adaptation is
best described as:
A. Atrophy
B. Hypertrophy
C. Metaplasia
D. Dysplasia
Correct Answer: C. Metaplasia
Rationale: Metaplasia is the reversible replacement of one mature cell
type by another mature cell type that is better able to tolerate the stress.
In Barrett esophagus, chronic acid exposure causes the normal squamous
epithelium of the distal esophagus to be replaced by columnar, mucus-
secreting epithelium. This adaptive change increases the risk of
dysplasia and malignancy but is initially protective.
Why the other options are incorrect:
A. Atrophy is a decrease in cell size or number, not a change in cell
type.
B. Hypertrophy is an increase in cell size, not replacement by another
cell type.
C. Correct.
D. Dysplasia is disordered cellular growth and differentiation, which
may develop later in Barrett esophagus but is not the initial adaptive
change.
,Learning Objective: Differentiate types of cellular adaptation and
identify metaplasia in response to chronic irritation.
Difficulty: Moderate
Question Type: Application
Question 2
Which cellular change is most characteristic of irreversible cell injury?
A. Cellular swelling
B. Ribosomal detachment from rough endoplasmic reticulum
C. Mitochondrial calcium accumulation and membrane rupture
D. Decreased ATP production with sodium-potassium pump failure
Correct Answer: C. Mitochondrial calcium accumulation and membrane
rupture
Rationale: Irreversible cell injury is marked by severe mitochondrial
damage, massive calcium influx, loss of membrane integrity, and
lysosomal enzyme leakage. While decreased ATP and cellular swelling
occur in reversible injury, mitochondrial rupture and nuclear pyknosis,
karyorrhexis, or karyolysis indicate cell death.
Why the other options are incorrect:
A. Cellular swelling is an early reversible change.
B. Ribosomal detachment reduces protein synthesis and can be
reversible.
C. Correct.
D. Decreased ATP and Na⁺/K⁺ pump failure occur early and may be
reversible if the insult is removed.
Learning Objective: Distinguish reversible from irreversible cell injury.
Difficulty: Moderate
Question Type: Recall
,Question 3
A patient is found to have a mutation in the TP53 tumor suppressor
gene. Which normal cellular function is most directly impaired?
A. Promotion of apoptosis in cells with damaged DNA
B. Acceleration of the cell cycle from G₁ to S phase
C. Angiogenesis factor production
D. Telomere elongation
Correct Answer: A. Promotion of apoptosis in cells with damaged DNA
Rationale: The TP53 gene encodes the p53 protein, which normally
detects DNA damage and either halts the cell cycle for repair or triggers
apoptosis if the damage is irreparable. Loss of p53 function allows
genetically damaged cells to survive and proliferate, contributing to
malignant transformation.
Why the other options are incorrect:
A. Correct.
B. p53 slows the cell cycle; it does not accelerate G₁ to S.
C. Angiogenesis is promoted by factors such as VEGF, not primarily
p53.
D. Telomere elongation is primarily controlled by telomerase, not p53.
Learning Objective: Explain the role of tumor suppressor genes in
carcinogenesis.
Difficulty: Moderate
Question Type: Application
Question 4
Which genetic inheritance pattern is characterized by a 50% chance of
affected offspring when one parent is affected, no skipping of
generations, and equal frequency in males and females?
A. Autosomal recessive
, B. X-linked recessive
C. Autosomal dominant
D. Mitochondrial
Correct Answer: C. Autosomal dominant
Rationale: Autosomal dominant disorders require only one mutated
allele for expression. An affected parent with one abnormal allele and
one normal allele has a 50% chance of passing the abnormal allele to
each child. Males and females are affected equally, and the trait appears
in successive generations.
Why the other options are incorrect:
A. Autosomal recessive disorders require two abnormal alleles and often
skip generations.
B. X-linked recessive disorders affect males predominantly and may
skip generations through carrier females.
C. Correct.
D. Mitochondrial inheritance is maternal and affects all children of an
affected mother.
Learning Objective: Recognize inheritance patterns of single-gene
disorders.
Difficulty: Easy
Question Type: Recall
Question 5
A tumor is poorly differentiated, shows marked nuclear pleomorphism,
and has infiltrated surrounding tissue. This tumor is best classified as:
A. Benign
B. Malignant
C. Carcinoma in situ
D. Hyperplasia
Questions, Correct Answers & Rationales |
Comprehensive Exam Review 2026
Question 1
A patient with chronic gastroesophageal reflux disease develops
columnar epithelium in the distal esophagus. This cellular adaptation is
best described as:
A. Atrophy
B. Hypertrophy
C. Metaplasia
D. Dysplasia
Correct Answer: C. Metaplasia
Rationale: Metaplasia is the reversible replacement of one mature cell
type by another mature cell type that is better able to tolerate the stress.
In Barrett esophagus, chronic acid exposure causes the normal squamous
epithelium of the distal esophagus to be replaced by columnar, mucus-
secreting epithelium. This adaptive change increases the risk of
dysplasia and malignancy but is initially protective.
Why the other options are incorrect:
A. Atrophy is a decrease in cell size or number, not a change in cell
type.
B. Hypertrophy is an increase in cell size, not replacement by another
cell type.
C. Correct.
D. Dysplasia is disordered cellular growth and differentiation, which
may develop later in Barrett esophagus but is not the initial adaptive
change.
,Learning Objective: Differentiate types of cellular adaptation and
identify metaplasia in response to chronic irritation.
Difficulty: Moderate
Question Type: Application
Question 2
Which cellular change is most characteristic of irreversible cell injury?
A. Cellular swelling
B. Ribosomal detachment from rough endoplasmic reticulum
C. Mitochondrial calcium accumulation and membrane rupture
D. Decreased ATP production with sodium-potassium pump failure
Correct Answer: C. Mitochondrial calcium accumulation and membrane
rupture
Rationale: Irreversible cell injury is marked by severe mitochondrial
damage, massive calcium influx, loss of membrane integrity, and
lysosomal enzyme leakage. While decreased ATP and cellular swelling
occur in reversible injury, mitochondrial rupture and nuclear pyknosis,
karyorrhexis, or karyolysis indicate cell death.
Why the other options are incorrect:
A. Cellular swelling is an early reversible change.
B. Ribosomal detachment reduces protein synthesis and can be
reversible.
C. Correct.
D. Decreased ATP and Na⁺/K⁺ pump failure occur early and may be
reversible if the insult is removed.
Learning Objective: Distinguish reversible from irreversible cell injury.
Difficulty: Moderate
Question Type: Recall
,Question 3
A patient is found to have a mutation in the TP53 tumor suppressor
gene. Which normal cellular function is most directly impaired?
A. Promotion of apoptosis in cells with damaged DNA
B. Acceleration of the cell cycle from G₁ to S phase
C. Angiogenesis factor production
D. Telomere elongation
Correct Answer: A. Promotion of apoptosis in cells with damaged DNA
Rationale: The TP53 gene encodes the p53 protein, which normally
detects DNA damage and either halts the cell cycle for repair or triggers
apoptosis if the damage is irreparable. Loss of p53 function allows
genetically damaged cells to survive and proliferate, contributing to
malignant transformation.
Why the other options are incorrect:
A. Correct.
B. p53 slows the cell cycle; it does not accelerate G₁ to S.
C. Angiogenesis is promoted by factors such as VEGF, not primarily
p53.
D. Telomere elongation is primarily controlled by telomerase, not p53.
Learning Objective: Explain the role of tumor suppressor genes in
carcinogenesis.
Difficulty: Moderate
Question Type: Application
Question 4
Which genetic inheritance pattern is characterized by a 50% chance of
affected offspring when one parent is affected, no skipping of
generations, and equal frequency in males and females?
A. Autosomal recessive
, B. X-linked recessive
C. Autosomal dominant
D. Mitochondrial
Correct Answer: C. Autosomal dominant
Rationale: Autosomal dominant disorders require only one mutated
allele for expression. An affected parent with one abnormal allele and
one normal allele has a 50% chance of passing the abnormal allele to
each child. Males and females are affected equally, and the trait appears
in successive generations.
Why the other options are incorrect:
A. Autosomal recessive disorders require two abnormal alleles and often
skip generations.
B. X-linked recessive disorders affect males predominantly and may
skip generations through carrier females.
C. Correct.
D. Mitochondrial inheritance is maternal and affects all children of an
affected mother.
Learning Objective: Recognize inheritance patterns of single-gene
disorders.
Difficulty: Easy
Question Type: Recall
Question 5
A tumor is poorly differentiated, shows marked nuclear pleomorphism,
and has infiltrated surrounding tissue. This tumor is best classified as:
A. Benign
B. Malignant
C. Carcinoma in situ
D. Hyperplasia
