WGU D115 ADVANCED
PATHOPHYSIOLOGY - 200 MULTIPLE
CHOICE QUESTIONS WITH ANSWERS AND
RATIONALES ALREADY GRADED A+
SECTION 1: CELLULAR FUNCTION AND GENETICS (Questions 1-40)
Question 1
A 42-year-old female presents with chronic fatigue and pallor. Laboratory
studies reveal hemoglobin of 8.2 g/dL and elevated levels of 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
Correct Answer: D
Rationale: Ferrochelatase inserts iron into protoporphyrin to form heme.
Impaired activity leads to accumulation of iron-free protoporphyrin.
,Aminolevulinic acid synthase is the rate-limiting enzyme of heme synthesis,
but its deficiency would not cause free protoporphyrin elevation .
---
Question 2
A researcher is studying a cell line that has lost the ability to undergo
apoptosis after DNA damage. Western blot analysis shows absent p53
protein expression. 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
Correct Answer: C
Rationale: p53 activates the intrinsic apoptotic pathway by upregulating
pro-apoptotic Bax and Bak while suppressing Bcl-2. Cyclin D-CDK4
complex formation is regulated by growth factor signaling, not directly by
p53 .
---
,Question 3
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
Correct Answer: A
Rationale: Hexosaminidase A deficiency causes Tay-Sachs disease, in
which GM2 ganglioside accumulates in lysosomes of neurons.
Glucocerebroside accumulates in Gaucher disease, and heparan sulfate
accumulation occurs in mucopolysaccharidoses .
---
Question 4
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
cellular adaptation?
, A) Anaplasia progressing to metaplasia
B) Hyperplasia progressing to hypertrophy
C) Atrophy progressing to aplasia
D) Metaplasia progressing to dysplasia
Correct Answer: D
Rationale: Chronic smoking causes squamous metaplasia of respiratory
epithelium, which can progress to dysplasia and eventually carcinoma. This
represents the metaplasia-dysplasia-neoplasia sequence .
---
Question 5
A 45-year-old male presents with calf pain during exercise that subsides
with rest (claudication). Examination reveals significant enlargement of
muscle cells in affected arteries due to increased workload. Which cellular
adaptation is occurring?
A) Atrophy
B) Hyperplasia
C) Hypertrophy
D) Dysplasia
PATHOPHYSIOLOGY - 200 MULTIPLE
CHOICE QUESTIONS WITH ANSWERS AND
RATIONALES ALREADY GRADED A+
SECTION 1: CELLULAR FUNCTION AND GENETICS (Questions 1-40)
Question 1
A 42-year-old female presents with chronic fatigue and pallor. Laboratory
studies reveal hemoglobin of 8.2 g/dL and elevated levels of 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
Correct Answer: D
Rationale: Ferrochelatase inserts iron into protoporphyrin to form heme.
Impaired activity leads to accumulation of iron-free protoporphyrin.
,Aminolevulinic acid synthase is the rate-limiting enzyme of heme synthesis,
but its deficiency would not cause free protoporphyrin elevation .
---
Question 2
A researcher is studying a cell line that has lost the ability to undergo
apoptosis after DNA damage. Western blot analysis shows absent p53
protein expression. 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
Correct Answer: C
Rationale: p53 activates the intrinsic apoptotic pathway by upregulating
pro-apoptotic Bax and Bak while suppressing Bcl-2. Cyclin D-CDK4
complex formation is regulated by growth factor signaling, not directly by
p53 .
---
,Question 3
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
Correct Answer: A
Rationale: Hexosaminidase A deficiency causes Tay-Sachs disease, in
which GM2 ganglioside accumulates in lysosomes of neurons.
Glucocerebroside accumulates in Gaucher disease, and heparan sulfate
accumulation occurs in mucopolysaccharidoses .
---
Question 4
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
cellular adaptation?
, A) Anaplasia progressing to metaplasia
B) Hyperplasia progressing to hypertrophy
C) Atrophy progressing to aplasia
D) Metaplasia progressing to dysplasia
Correct Answer: D
Rationale: Chronic smoking causes squamous metaplasia of respiratory
epithelium, which can progress to dysplasia and eventually carcinoma. This
represents the metaplasia-dysplasia-neoplasia sequence .
---
Question 5
A 45-year-old male presents with calf pain during exercise that subsides
with rest (claudication). Examination reveals significant enlargement of
muscle cells in affected arteries due to increased workload. Which cellular
adaptation is occurring?
A) Atrophy
B) Hyperplasia
C) Hypertrophy
D) Dysplasia
