WGU D115 Advanced Pathophysiology OA Exam
2025/2026 – Complete Exam Questions and
Answers
1. A 62-year-old patient with chronic hypertension develops left ventricular hypertrophy. Which
cellular adaptation best describes this change?
A) Hyperplasia
B) Metaplasia
C) Hypertrophy
D) Dysplasia
Rationale: Hypertrophy is an increase in cell size in response to increased workload. Chronic
hypertension increases afterload on the left ventricle, causing myocardial cells to enlarge to
meet increased demand. This is a compensatory adaptation that can become pathologic.
2. A researcher studies a cell line that has lost the ability to undergo apoptosis after DNA
damage. Western blot shows absent p53 protein. Loss of p53 function most directly affects
which cellular process?
A) Ras protein GTPase activity
B) Cyclin D-CDK4 complex formation
C) Activation of pro-apoptotic Bax and Bak proteins
D) Telomerase reverse transcriptase expression
Rationale: p53 activates the intrinsic apoptotic pathway by upregulating pro-apoptotic Bax
and Bak while suppressing anti-apoptotic Bcl-2. Loss of p53 prevents apoptosis of cells with DNA
damage, allowing potentially malignant cells to survive and proliferate.
3. A patient with COPD develops squamous metaplasia in the bronchial epithelium. Which
statement best describes this cellular change?
A) An increase in cell size
B) A reversible replacement of one differentiated cell type with another
C) An increase in the number of cells
D) A decrease in cell size
,Rationale: Metaplasia is a reversible change in which one differentiated cell type is replaced
by another. In COPD, chronic irritation causes normal ciliated columnar epithelium to be
replaced by stratified squamous epithelium, which is more resilient but loses protective
functions.
4. A 42-year-old female presents with chronic fatigue and pallor. Labs reveal hemoglobin 8.2
g/dL and elevated free protoporphyrin in erythrocytes. This condition is most likely caused by
impaired activity of which enzyme?
A) Uroporphyrinogen decarboxylase
B) Aminolevulinic acid synthase
C) Porphobilinogen deaminase
D) Ferrochelatase
Rationale: Ferrochelatase inserts iron into protoporphyrin to form heme; impairment leads
to iron-free protoporphyrin accumulation. This results in erythropoietic protoporphyria,
characterized by anemia and photosensitivity.
5. A child is born with an extra copy of chromosome 21. Which chromosomal abnormality is
present, and what is the most common cause?
A) Turner syndrome (45, X); nondisjunction in paternal meiosis
B) Down syndrome (Trisomy 21); nondisjunction during meiosis
C) Klinefelter syndrome (47, XXY); nondisjunction in maternal meiosis
D) Edward syndrome (Trisomy 18); chromosomal translocation
Rationale: Down syndrome results from trisomy 21, most commonly due to meiotic
nondisjunction (failure of chromosomes to separate properly). Risk increases with advanced
maternal age.
6. A 3-month-old infant presents with severe developmental delay, seizures, and a cherry-red
spot on the macula. Enzyme analysis reveals deficient hexosaminidase A activity. This disorder
results from accumulation of which substance?
A) GM2 ganglioside
B) Glucocerebroside
,C) Sphingomyelin
D) Heparan sulfate
Rationale: Hexosaminidase A deficiency causes Tay-Sachs disease, in which GM2 ganglioside
accumulates in neuronal lysosomes. Glucocerebroside accumulates in Gaucher disease.
7. Which process is primarily responsible for maintaining genetic stability during cell division?
A) Protein folding
B) DNA replication proofreading
C) Telomere elongation
D) Histone methylation
Rationale: DNA polymerase possesses proofreading capabilities that identify and correct
mismatched nucleotides during replication, reducing mutation rates and preserving genetic
integrity.
8. A 55-year-old male with a 30-pack-year smoking history develops a lung mass. Biopsy reveals
squamous cell carcinoma. The transition from normal respiratory epithelium to squamous cell
carcinoma best exemplifies which sequence?
A) Anaplasia progressing to metaplasia
B) Hyperplasia progressing to hypertrophy
C) Atrophy progressing to aplasia
D) Metaplasia progressing to dysplasia
Rationale: Chronic smoking causes squamous metaplasia of respiratory epithelium, which
can progress to dysplasia and carcinoma. Hyperplasia and hypertrophy are increases in cell
number and size, not the pattern seen in this sequence.
9. A patient with renal failure has a serum potassium level of 6.2 mEq/L. This electrolyte
imbalance predisposes to which cardiac complication?
A) Atrial fibrillation
B) Ventricular tachycardia
C) First-degree heart block
D) Sinus bradycardia
, Rationale: Hyperkalemia (>5.5 mEq/L) can cause life-threatening arrhythmias such as
ventricular tachycardia, ventricular fibrillation, and asystole. ECG findings include peaked T
waves, widened QRS, and eventual sine wave pattern.
10. In a patient with severe sepsis, which vasoactive mediator is most responsible for profound
hypotension?
A) Endothelin
B) Nitric oxide
C) Angiotensin II
D) Norepinephrine
Rationale: In sepsis, bacterial products (e.g., lipopolysaccharide) stimulate iNOS, leading to
excessive nitric oxide production. NO causes vasodilation and hypotension.
11. A patient with type 1 diabetes is admitted with nausea, vomiting, and deep rapid breathing
(Kussmaul respirations). Which acid-base disturbance is most likely?
A) Metabolic acidosis
B) Metabolic alkalosis
C) Respiratory acidosis
D) Respiratory alkalosis
Rationale: Diabetic ketoacidosis (DKA) results in metabolic acidosis due to accumulation of
ketone bodies. Kussmaul respirations are the body's compensatory hyperventilation to lower
PaCO2.
12. A 65-year-old female with hypertension presents with sudden, severe "tearing" chest pain
radiating to the back. Blood pressure is 160/90 in the right arm and 110/70 in the left arm.
What is the most likely diagnosis?
A) Myocardial infarction
B) Aortic dissection
C) Pulmonary embolism
D) Pericarditis
2025/2026 – Complete Exam Questions and
Answers
1. A 62-year-old patient with chronic hypertension develops left ventricular hypertrophy. Which
cellular adaptation best describes this change?
A) Hyperplasia
B) Metaplasia
C) Hypertrophy
D) Dysplasia
Rationale: Hypertrophy is an increase in cell size in response to increased workload. Chronic
hypertension increases afterload on the left ventricle, causing myocardial cells to enlarge to
meet increased demand. This is a compensatory adaptation that can become pathologic.
2. A researcher studies a cell line that has lost the ability to undergo apoptosis after DNA
damage. Western blot shows absent p53 protein. Loss of p53 function most directly affects
which cellular process?
A) Ras protein GTPase activity
B) Cyclin D-CDK4 complex formation
C) Activation of pro-apoptotic Bax and Bak proteins
D) Telomerase reverse transcriptase expression
Rationale: p53 activates the intrinsic apoptotic pathway by upregulating pro-apoptotic Bax
and Bak while suppressing anti-apoptotic Bcl-2. Loss of p53 prevents apoptosis of cells with DNA
damage, allowing potentially malignant cells to survive and proliferate.
3. A patient with COPD develops squamous metaplasia in the bronchial epithelium. Which
statement best describes this cellular change?
A) An increase in cell size
B) A reversible replacement of one differentiated cell type with another
C) An increase in the number of cells
D) A decrease in cell size
,Rationale: Metaplasia is a reversible change in which one differentiated cell type is replaced
by another. In COPD, chronic irritation causes normal ciliated columnar epithelium to be
replaced by stratified squamous epithelium, which is more resilient but loses protective
functions.
4. A 42-year-old female presents with chronic fatigue and pallor. Labs reveal hemoglobin 8.2
g/dL and elevated free protoporphyrin in erythrocytes. This condition is most likely caused by
impaired activity of which enzyme?
A) Uroporphyrinogen decarboxylase
B) Aminolevulinic acid synthase
C) Porphobilinogen deaminase
D) Ferrochelatase
Rationale: Ferrochelatase inserts iron into protoporphyrin to form heme; impairment leads
to iron-free protoporphyrin accumulation. This results in erythropoietic protoporphyria,
characterized by anemia and photosensitivity.
5. A child is born with an extra copy of chromosome 21. Which chromosomal abnormality is
present, and what is the most common cause?
A) Turner syndrome (45, X); nondisjunction in paternal meiosis
B) Down syndrome (Trisomy 21); nondisjunction during meiosis
C) Klinefelter syndrome (47, XXY); nondisjunction in maternal meiosis
D) Edward syndrome (Trisomy 18); chromosomal translocation
Rationale: Down syndrome results from trisomy 21, most commonly due to meiotic
nondisjunction (failure of chromosomes to separate properly). Risk increases with advanced
maternal age.
6. A 3-month-old infant presents with severe developmental delay, seizures, and a cherry-red
spot on the macula. Enzyme analysis reveals deficient hexosaminidase A activity. This disorder
results from accumulation of which substance?
A) GM2 ganglioside
B) Glucocerebroside
,C) Sphingomyelin
D) Heparan sulfate
Rationale: Hexosaminidase A deficiency causes Tay-Sachs disease, in which GM2 ganglioside
accumulates in neuronal lysosomes. Glucocerebroside accumulates in Gaucher disease.
7. Which process is primarily responsible for maintaining genetic stability during cell division?
A) Protein folding
B) DNA replication proofreading
C) Telomere elongation
D) Histone methylation
Rationale: DNA polymerase possesses proofreading capabilities that identify and correct
mismatched nucleotides during replication, reducing mutation rates and preserving genetic
integrity.
8. A 55-year-old male with a 30-pack-year smoking history develops a lung mass. Biopsy reveals
squamous cell carcinoma. The transition from normal respiratory epithelium to squamous cell
carcinoma best exemplifies which sequence?
A) Anaplasia progressing to metaplasia
B) Hyperplasia progressing to hypertrophy
C) Atrophy progressing to aplasia
D) Metaplasia progressing to dysplasia
Rationale: Chronic smoking causes squamous metaplasia of respiratory epithelium, which
can progress to dysplasia and carcinoma. Hyperplasia and hypertrophy are increases in cell
number and size, not the pattern seen in this sequence.
9. A patient with renal failure has a serum potassium level of 6.2 mEq/L. This electrolyte
imbalance predisposes to which cardiac complication?
A) Atrial fibrillation
B) Ventricular tachycardia
C) First-degree heart block
D) Sinus bradycardia
, Rationale: Hyperkalemia (>5.5 mEq/L) can cause life-threatening arrhythmias such as
ventricular tachycardia, ventricular fibrillation, and asystole. ECG findings include peaked T
waves, widened QRS, and eventual sine wave pattern.
10. In a patient with severe sepsis, which vasoactive mediator is most responsible for profound
hypotension?
A) Endothelin
B) Nitric oxide
C) Angiotensin II
D) Norepinephrine
Rationale: In sepsis, bacterial products (e.g., lipopolysaccharide) stimulate iNOS, leading to
excessive nitric oxide production. NO causes vasodilation and hypotension.
11. A patient with type 1 diabetes is admitted with nausea, vomiting, and deep rapid breathing
(Kussmaul respirations). Which acid-base disturbance is most likely?
A) Metabolic acidosis
B) Metabolic alkalosis
C) Respiratory acidosis
D) Respiratory alkalosis
Rationale: Diabetic ketoacidosis (DKA) results in metabolic acidosis due to accumulation of
ketone bodies. Kussmaul respirations are the body's compensatory hyperventilation to lower
PaCO2.
12. A 65-year-old female with hypertension presents with sudden, severe "tearing" chest pain
radiating to the back. Blood pressure is 160/90 in the right arm and 110/70 in the left arm.
What is the most likely diagnosis?
A) Myocardial infarction
B) Aortic dissection
C) Pulmonary embolism
D) Pericarditis
