WGU D115 ADVANCED PATHOPHYSIOLOGY OA EXAM
BANK 2026/2027 | 2 Complete OA Versions | OA Readiness
Practice Exam | Comprehensive Study Guide | Expert Verified
| Pass Guaranteed - A+ Graded
VERSION 1: OBJECTIVE ASSESSMENT (120 QUESTIONS)
DOMAIN 1: CELLULAR BIOLOGY & GENETICS (15 Questions)
Q1: A 58-year-old male with a 30-pack-year smoking history presents with a lung mass.
Biopsy reveals dysplastic cells showing loss of contact inhibition, increased mitotic
figures, and nuclear pleomorphism. Which cellular mechanism is primarily responsible
for the loss of contact inhibition observed in these malignant cells?
A. Activation of tumor suppressor genes (p53, Rb)
B. Decreased expression of cell adhesion molecules (E-cadherin)
C. Overexpression of telomerase preventing cellular senescence
D. Mutation in DNA repair genes leading to genomic instability
Correct Answer: B
Rationale: [CORRECT] Loss of contact inhibition in malignant cells is primarily due to
decreased expression or dysfunction of cell adhesion molecules, particularly
E-cadherin. E-cadherin is a transmembrane glycoprotein responsible for
,calcium-dependent cell-cell adhesion. Reduced E-cadherin expression allows cells to
proliferate without contact-dependent growth arrest and facilitates detachment from
the primary tumor, a prerequisite for metastasis.
Option A is incorrect because activation of tumor suppressor genes would inhibit rather
than promote malignancy—p53 and Rb are tumor suppressor genes that are typically
inactivated, not activated, in cancer. Option C is incorrect because telomerase
overexpression prevents cellular senescence and contributes to immortalization but
does not directly affect contact inhibition. Option D is incorrect because DNA repair
gene mutations contribute to genomic instability and accumulation of mutations but do
not directly cause loss of contact inhibition.
Q2: A 45-year-old woman with chronic hypertension undergoes cardiac catheterization
showing left ventricular wall thickness of 15mm (normal <11mm). This cellular
adaptation is best classified as:
A. Atrophy
B. Hypertrophy
C. Hyperplasia
D. Metaplasia
Correct Answer: B
Rationale: [CORRECT] This represents cardiac hypertrophy—an increase in cell size (not
number) of cardiac myocytes in response to increased workload from chronic
hypertension. Hypertrophy occurs in tissues where cells cannot divide (permanent cells
,like cardiac myocytes, skeletal muscle, neurons). The increased wall thickness results
from individual myocytes enlarging to generate more contractile force against elevated
afterload.
Option A (atrophy) is incorrect as it represents decreased cell size. Option C
(hyperplasia) is incorrect because cardiac myocytes are terminally differentiated cells
that cannot undergo mitosis; therefore, they cannot increase in number. Option D
(metaplasia) is incorrect as it represents a change from one differentiated cell type to
another, not enlargement of existing cells.
Q3: A patient presents with acute myocardial infarction. Within 24-72 hours, the
infarcted myocardium shows neutrophilic infiltration and coagulative necrosis. Which
type of necrosis is occurring, and what is the primary mechanism?
A. Liquefactive necrosis due to enzymatic digestion by neutrophils
B. Coagulative necrosis due to denaturation of structural and enzymatic proteins
C. Caseous necrosis due to granulomatous inflammation
D. Fat necrosis due to lipase activation
Correct Answer: B
Rationale: [CORRECT] Coagulative necrosis occurs in myocardial infarction due to
ischemia causing denaturation of structural and enzymatic proteins, preserving the
tissue architecture for several days. The ischemic injury denatures proteins, preventing
their digestion by lysosomal enzymes, resulting in "ghost" outlines of cells. The
neutrophilic infiltration represents the inflammatory response to clear necrotic debris.
, Option A is incorrect because liquefactive necrosis occurs in the brain (due to high lipid
content and lack of structural collagen) and abscesses (due to enzymatic digestion by
neutrophils). Option C is incorrect because caseous necrosis is characteristic of
tuberculosis, showing amorphous, eosinophilic debris without preserved architecture.
Option D is incorrect because fat necrosis occurs in pancreatic or breast tissue due to
lipase activation.
Q4: A newborn with severe combined immunodeficiency (SCID) has a mutation in the
IL-2 receptor gamma chain. This mutation affects which cellular process?
A. DNA repair mechanisms
B. Cytokine signaling and T-cell development
C. Cell cycle checkpoint control
D. Apoptosis regulation
Correct Answer: B
Rationale: [CORRECT] The IL-2 receptor gamma chain (common gamma chain, γc) is a
shared component of receptors for IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21. Mutations in this
chain (X-linked SCID) impair cytokine signaling critical for T-cell and NK-cell
development. IL-7 signaling is particularly important for T-cell precursor survival and
proliferation in the thymus.
Option A is incorrect—DNA repair defects cause conditions like ataxia-telangiectasia or
Fanconi anemia, not SCID. Option C is incorrect—cell cycle checkpoint defects lead to
BANK 2026/2027 | 2 Complete OA Versions | OA Readiness
Practice Exam | Comprehensive Study Guide | Expert Verified
| Pass Guaranteed - A+ Graded
VERSION 1: OBJECTIVE ASSESSMENT (120 QUESTIONS)
DOMAIN 1: CELLULAR BIOLOGY & GENETICS (15 Questions)
Q1: A 58-year-old male with a 30-pack-year smoking history presents with a lung mass.
Biopsy reveals dysplastic cells showing loss of contact inhibition, increased mitotic
figures, and nuclear pleomorphism. Which cellular mechanism is primarily responsible
for the loss of contact inhibition observed in these malignant cells?
A. Activation of tumor suppressor genes (p53, Rb)
B. Decreased expression of cell adhesion molecules (E-cadherin)
C. Overexpression of telomerase preventing cellular senescence
D. Mutation in DNA repair genes leading to genomic instability
Correct Answer: B
Rationale: [CORRECT] Loss of contact inhibition in malignant cells is primarily due to
decreased expression or dysfunction of cell adhesion molecules, particularly
E-cadherin. E-cadherin is a transmembrane glycoprotein responsible for
,calcium-dependent cell-cell adhesion. Reduced E-cadherin expression allows cells to
proliferate without contact-dependent growth arrest and facilitates detachment from
the primary tumor, a prerequisite for metastasis.
Option A is incorrect because activation of tumor suppressor genes would inhibit rather
than promote malignancy—p53 and Rb are tumor suppressor genes that are typically
inactivated, not activated, in cancer. Option C is incorrect because telomerase
overexpression prevents cellular senescence and contributes to immortalization but
does not directly affect contact inhibition. Option D is incorrect because DNA repair
gene mutations contribute to genomic instability and accumulation of mutations but do
not directly cause loss of contact inhibition.
Q2: A 45-year-old woman with chronic hypertension undergoes cardiac catheterization
showing left ventricular wall thickness of 15mm (normal <11mm). This cellular
adaptation is best classified as:
A. Atrophy
B. Hypertrophy
C. Hyperplasia
D. Metaplasia
Correct Answer: B
Rationale: [CORRECT] This represents cardiac hypertrophy—an increase in cell size (not
number) of cardiac myocytes in response to increased workload from chronic
hypertension. Hypertrophy occurs in tissues where cells cannot divide (permanent cells
,like cardiac myocytes, skeletal muscle, neurons). The increased wall thickness results
from individual myocytes enlarging to generate more contractile force against elevated
afterload.
Option A (atrophy) is incorrect as it represents decreased cell size. Option C
(hyperplasia) is incorrect because cardiac myocytes are terminally differentiated cells
that cannot undergo mitosis; therefore, they cannot increase in number. Option D
(metaplasia) is incorrect as it represents a change from one differentiated cell type to
another, not enlargement of existing cells.
Q3: A patient presents with acute myocardial infarction. Within 24-72 hours, the
infarcted myocardium shows neutrophilic infiltration and coagulative necrosis. Which
type of necrosis is occurring, and what is the primary mechanism?
A. Liquefactive necrosis due to enzymatic digestion by neutrophils
B. Coagulative necrosis due to denaturation of structural and enzymatic proteins
C. Caseous necrosis due to granulomatous inflammation
D. Fat necrosis due to lipase activation
Correct Answer: B
Rationale: [CORRECT] Coagulative necrosis occurs in myocardial infarction due to
ischemia causing denaturation of structural and enzymatic proteins, preserving the
tissue architecture for several days. The ischemic injury denatures proteins, preventing
their digestion by lysosomal enzymes, resulting in "ghost" outlines of cells. The
neutrophilic infiltration represents the inflammatory response to clear necrotic debris.
, Option A is incorrect because liquefactive necrosis occurs in the brain (due to high lipid
content and lack of structural collagen) and abscesses (due to enzymatic digestion by
neutrophils). Option C is incorrect because caseous necrosis is characteristic of
tuberculosis, showing amorphous, eosinophilic debris without preserved architecture.
Option D is incorrect because fat necrosis occurs in pancreatic or breast tissue due to
lipase activation.
Q4: A newborn with severe combined immunodeficiency (SCID) has a mutation in the
IL-2 receptor gamma chain. This mutation affects which cellular process?
A. DNA repair mechanisms
B. Cytokine signaling and T-cell development
C. Cell cycle checkpoint control
D. Apoptosis regulation
Correct Answer: B
Rationale: [CORRECT] The IL-2 receptor gamma chain (common gamma chain, γc) is a
shared component of receptors for IL-2, IL-4, IL-7, IL-9, IL-15, and IL-21. Mutations in this
chain (X-linked SCID) impair cytokine signaling critical for T-cell and NK-cell
development. IL-7 signaling is particularly important for T-cell precursor survival and
proliferation in the thymus.
Option A is incorrect—DNA repair defects cause conditions like ataxia-telangiectasia or
Fanconi anemia, not SCID. Option C is incorrect—cell cycle checkpoint defects lead to
