UT Tyler FNP NURS 5350 Adv Patho Exam 1 Questions Actual
Exam 2026/2027 with Detailed Rationales | Complete Exam-Style
Questions | Graded A+ Pass Guaranteed
Total Questions: 60
SECTION 1: Cellular Pathology and Genetics
1. A 28-year-old patient presents with progressive muscle weakness, exercise
intolerance, and elevated serum lactate. Muscle biopsy reveals ragged-red fibers
with abnormal mitochondrial proliferation. Which pathophysiological mechanism
best explains this patient's cellular dysfunction?
A. Defective oxidative phosphorylation leading to impaired ATP synthesis and
compensatory mitochondrial proliferation
B. Lysosomal enzyme deficiency causing accumulation of glycogen within muscle fibers
C. Mutations in dystrophin gene resulting in sarcolemmal instability and calcium influx
D. Impaired fatty acid beta-oxidation due to carnitine deficiency with secondary energy
failure
Correct Answer: A. Defective oxidative phosphorylation leading to impaired ATP
synthesis and compensatory mitochondrial proliferation
Rationale: This patient presents with classic features of a mitochondrial myopathy.
Ragged-red fibers on muscle biopsy are pathognomonic for mitochondrial disease,
representing accumulations of abnormal mitochondria beneath the sarcolemma.
Mitochondrial DNA mutations affecting oxidative phosphorylation complexes impair
ATP production, leading to compensatory mitochondrial proliferation (hence the
ragged-red appearance) and elevated lactate due to anaerobic metabolism. Option B
describes Pompe disease (glycogen storage disease type II), which would show
vacuolar myopathy with glycogen accumulation, not ragged-red fibers. Option C
describes Duchenne or Becker muscular dystrophy, which presents with dystrophin
,deficiency, necrotic fibers, and fatty replacement without ragged-red fibers or lactic
acidosis. Option D describes a fatty acid oxidation disorder, which typically presents
with hypoketotic hypoglycemia during fasting and lipid accumulation, not ragged-red
fibers or chronic progressive weakness with lactic acidosis.
2. A 45-year-old woman with a history of BRCA1 gene mutation undergoes
prophylactic bilateral mastectomy. Her oncologist explains that this mutation
significantly increases her lifetime risk of breast cancer. Which cellular
mechanism is primarily responsible for the oncogenic potential of BRCA1
mutations?
A. Loss of homologous recombination DNA repair leading to genomic instability and
accumulation of mutations
B. Activation of telomerase preventing cellular senescence and enabling unlimited
replication
C. Constitutive activation of the PI3K/AKT/mTOR signaling pathway driving
uncontrolled proliferation
D. Defective spindle assembly checkpoint permitting aneuploidy and chromosomal
missegregation
Correct Answer: A. Loss of homologous recombination DNA repair leading to genomic
instability and accumulation of mutations
Rationale: BRCA1 is a tumor suppressor gene that functions in DNA double-strand break
repair via homologous recombination. Mutations result in defective repair of DNA
damage, particularly double-strand breaks, leading to genomic instability, chromosomal
rearrangements, and accumulation of oncogenic mutations. This explains the high
penetrance of breast and ovarian cancers. Option B describes telomerase activation, a
hallmark of cancer but not the primary mechanism of BRCA1-associated
carcinogenesis. Option C describes the mechanism of PTEN loss or PIK3CA mutations,
commonly seen in sporadic breast cancers but not the primary BRCA1 pathway. Option
D describes mechanisms associated with checkpoint kinase deficiencies (e.g., BUB1,
,MAD2) or TP53 mutations, not BRCA1. BRCA1-mutated tumors are characterized by
specific genomic scars from defective homologous recombination.
3. A 62-year-old male with chronic alcohol use disorder presents with confusion,
ataxia, and ophthalmoplegia. Brain MRI shows mammillary body atrophy and
symmetric hyperintensity in the periaqueductal gray matter. Which cellular
pathophysiological process is most directly responsible for the neurologic
deficits?
A. Thiamine pyrophosphate cofactor deficiency impairing cellular energy metabolism
and leading to lactic acidosis and cellular ATP depletion
B. Direct ethanol neurotoxicity causing neuronal apoptosis via NMDA receptor
excitotoxicity and oxidative stress
C. Acetaldehyde accumulation cross-linking proteins and generating reactive oxygen
species causing direct neuronal injury
D. Hepatic encephalopathy due to ammonia-induced astrocyte swelling and glutamine
accumulation
Correct Answer: A. Thiamine pyrophosphate cofactor deficiency impairing cellular
energy metabolism and leading to lactic acidosis and cellular ATP depletion
Rationale: This patient has Wernicke encephalopathy, the classic triad of confusion,
ataxia, and ophthalmoplegia, caused by thiamine (vitamin B1) deficiency. Thiamine
pyrophosphate (TPP) is an essential cofactor for multiple enzymes in glucose
metabolism (pyruvate dehydrogenase, alpha-ketoglutarate dehydrogenase,
transketolase). Deficiency impairs cellular ATP production, causes lactic acidosis, and
leads to cellular energy failure, particularly affecting vulnerable brain regions
(mammillary bodies, thalamus, periaqueductal gray). Option B describes mechanisms
of chronic alcohol neurotoxicity but does not explain the acute triad or mammillary body
findings. Option C describes acetaldehyde toxicity, which contributes to hepatic and
cardiovascular damage but is not the primary mechanism of Wernicke encephalopathy.
Option D describes hepatic encephalopathy, which presents with asterixis, elevated
, ammonia, and diffuse cerebral edema without the specific triad or mammillary body
atrophy.
4. A 6-year-old child presents with recurrent infections, eczematous dermatitis, and
thrombocytopenia with small platelets. Genetic testing reveals a mutation in the
WAS gene. Which cellular mechanism underlies the immunodeficiency in this
disorder?
A. Defective actin cytoskeleton reorganization in hematopoietic cells impairing immune
synapse formation and cell migration
B. Failure of V(D)J recombination due to RAG1/RAG2 deficiency blocking lymphocyte
development
C. Defective phagolysosome fusion in neutrophils leading to impaired intracellular
bacterial killing
D. Absence of the IL-2 receptor gamma chain preventing T cell maturation and signaling
Correct Answer: A. Defective actin cytoskeleton reorganization in hematopoietic cells
impairing immune synapse formation and cell migration
Rationale: Wiskott-Aldrich syndrome (WAS) is caused by mutations in the WAS gene
encoding Wiskott-Aldrich syndrome protein (WASp), a key regulator of actin
cytoskeleton reorganization in hematopoietic cells. WASp deficiency impairs T cell
activation via defective immune synapse formation, reduces B cell responses, and
causes cytoskeletal abnormalities leading to small platelets and thrombocytopenia.
Option B describes severe combined immunodeficiency (SCID) due to RAG deficiencies,
which presents with absent T and B cells but no eczema or thrombocytopenia. Option C
describes chronic granulomatous disease (CGD), characterized by defective NADPH
oxidase and impaired respiratory burst, not the triad of infections, eczema, and
thrombocytopenia. Option D describes X-linked SCID due to IL2RG mutations, which
presents with absent T and NK cells but normal platelets and no eczema.
Exam 2026/2027 with Detailed Rationales | Complete Exam-Style
Questions | Graded A+ Pass Guaranteed
Total Questions: 60
SECTION 1: Cellular Pathology and Genetics
1. A 28-year-old patient presents with progressive muscle weakness, exercise
intolerance, and elevated serum lactate. Muscle biopsy reveals ragged-red fibers
with abnormal mitochondrial proliferation. Which pathophysiological mechanism
best explains this patient's cellular dysfunction?
A. Defective oxidative phosphorylation leading to impaired ATP synthesis and
compensatory mitochondrial proliferation
B. Lysosomal enzyme deficiency causing accumulation of glycogen within muscle fibers
C. Mutations in dystrophin gene resulting in sarcolemmal instability and calcium influx
D. Impaired fatty acid beta-oxidation due to carnitine deficiency with secondary energy
failure
Correct Answer: A. Defective oxidative phosphorylation leading to impaired ATP
synthesis and compensatory mitochondrial proliferation
Rationale: This patient presents with classic features of a mitochondrial myopathy.
Ragged-red fibers on muscle biopsy are pathognomonic for mitochondrial disease,
representing accumulations of abnormal mitochondria beneath the sarcolemma.
Mitochondrial DNA mutations affecting oxidative phosphorylation complexes impair
ATP production, leading to compensatory mitochondrial proliferation (hence the
ragged-red appearance) and elevated lactate due to anaerobic metabolism. Option B
describes Pompe disease (glycogen storage disease type II), which would show
vacuolar myopathy with glycogen accumulation, not ragged-red fibers. Option C
describes Duchenne or Becker muscular dystrophy, which presents with dystrophin
,deficiency, necrotic fibers, and fatty replacement without ragged-red fibers or lactic
acidosis. Option D describes a fatty acid oxidation disorder, which typically presents
with hypoketotic hypoglycemia during fasting and lipid accumulation, not ragged-red
fibers or chronic progressive weakness with lactic acidosis.
2. A 45-year-old woman with a history of BRCA1 gene mutation undergoes
prophylactic bilateral mastectomy. Her oncologist explains that this mutation
significantly increases her lifetime risk of breast cancer. Which cellular
mechanism is primarily responsible for the oncogenic potential of BRCA1
mutations?
A. Loss of homologous recombination DNA repair leading to genomic instability and
accumulation of mutations
B. Activation of telomerase preventing cellular senescence and enabling unlimited
replication
C. Constitutive activation of the PI3K/AKT/mTOR signaling pathway driving
uncontrolled proliferation
D. Defective spindle assembly checkpoint permitting aneuploidy and chromosomal
missegregation
Correct Answer: A. Loss of homologous recombination DNA repair leading to genomic
instability and accumulation of mutations
Rationale: BRCA1 is a tumor suppressor gene that functions in DNA double-strand break
repair via homologous recombination. Mutations result in defective repair of DNA
damage, particularly double-strand breaks, leading to genomic instability, chromosomal
rearrangements, and accumulation of oncogenic mutations. This explains the high
penetrance of breast and ovarian cancers. Option B describes telomerase activation, a
hallmark of cancer but not the primary mechanism of BRCA1-associated
carcinogenesis. Option C describes the mechanism of PTEN loss or PIK3CA mutations,
commonly seen in sporadic breast cancers but not the primary BRCA1 pathway. Option
D describes mechanisms associated with checkpoint kinase deficiencies (e.g., BUB1,
,MAD2) or TP53 mutations, not BRCA1. BRCA1-mutated tumors are characterized by
specific genomic scars from defective homologous recombination.
3. A 62-year-old male with chronic alcohol use disorder presents with confusion,
ataxia, and ophthalmoplegia. Brain MRI shows mammillary body atrophy and
symmetric hyperintensity in the periaqueductal gray matter. Which cellular
pathophysiological process is most directly responsible for the neurologic
deficits?
A. Thiamine pyrophosphate cofactor deficiency impairing cellular energy metabolism
and leading to lactic acidosis and cellular ATP depletion
B. Direct ethanol neurotoxicity causing neuronal apoptosis via NMDA receptor
excitotoxicity and oxidative stress
C. Acetaldehyde accumulation cross-linking proteins and generating reactive oxygen
species causing direct neuronal injury
D. Hepatic encephalopathy due to ammonia-induced astrocyte swelling and glutamine
accumulation
Correct Answer: A. Thiamine pyrophosphate cofactor deficiency impairing cellular
energy metabolism and leading to lactic acidosis and cellular ATP depletion
Rationale: This patient has Wernicke encephalopathy, the classic triad of confusion,
ataxia, and ophthalmoplegia, caused by thiamine (vitamin B1) deficiency. Thiamine
pyrophosphate (TPP) is an essential cofactor for multiple enzymes in glucose
metabolism (pyruvate dehydrogenase, alpha-ketoglutarate dehydrogenase,
transketolase). Deficiency impairs cellular ATP production, causes lactic acidosis, and
leads to cellular energy failure, particularly affecting vulnerable brain regions
(mammillary bodies, thalamus, periaqueductal gray). Option B describes mechanisms
of chronic alcohol neurotoxicity but does not explain the acute triad or mammillary body
findings. Option C describes acetaldehyde toxicity, which contributes to hepatic and
cardiovascular damage but is not the primary mechanism of Wernicke encephalopathy.
Option D describes hepatic encephalopathy, which presents with asterixis, elevated
, ammonia, and diffuse cerebral edema without the specific triad or mammillary body
atrophy.
4. A 6-year-old child presents with recurrent infections, eczematous dermatitis, and
thrombocytopenia with small platelets. Genetic testing reveals a mutation in the
WAS gene. Which cellular mechanism underlies the immunodeficiency in this
disorder?
A. Defective actin cytoskeleton reorganization in hematopoietic cells impairing immune
synapse formation and cell migration
B. Failure of V(D)J recombination due to RAG1/RAG2 deficiency blocking lymphocyte
development
C. Defective phagolysosome fusion in neutrophils leading to impaired intracellular
bacterial killing
D. Absence of the IL-2 receptor gamma chain preventing T cell maturation and signaling
Correct Answer: A. Defective actin cytoskeleton reorganization in hematopoietic cells
impairing immune synapse formation and cell migration
Rationale: Wiskott-Aldrich syndrome (WAS) is caused by mutations in the WAS gene
encoding Wiskott-Aldrich syndrome protein (WASp), a key regulator of actin
cytoskeleton reorganization in hematopoietic cells. WASp deficiency impairs T cell
activation via defective immune synapse formation, reduces B cell responses, and
causes cytoskeletal abnormalities leading to small platelets and thrombocytopenia.
Option B describes severe combined immunodeficiency (SCID) due to RAG deficiencies,
which presents with absent T and B cells but no eczema or thrombocytopenia. Option C
describes chronic granulomatous disease (CGD), characterized by defective NADPH
oxidase and impaired respiratory burst, not the triad of infections, eczema, and
thrombocytopenia. Option D describes X-linked SCID due to IL2RG mutations, which
presents with absent T and NK cells but normal platelets and no eczema.
