NR 507 / NR507 Advanced Pathophysiology Midterm
Exam | ACTUAL EXAM | Questions & Verified Answers |
Latest Update – Chamberlain University
1. A 28-year-old woman with sustained aerobic training exhibits increased
mitochondrial density in skeletal muscle. Which cellular adaptation best explains
this change?
A. Hypertrophy
B. Hyperplasia
C. Metaplasia
D. Biogenesis
Correct Answer: D
Rationale: Mitochondrial biogenesis is the process by which new mitochondria are
formed, driven by transcriptional co-activators such as PGC-1α in response to
endurance exercise. Hypertrophy (A) refers to increased cell size, not organelle number.
Hyperplasia (B) is an increase in cell number, irrelevant here. Metaplasia (C) is a
reversible change of one differentiated cell type to another.
2. A 5-year-old boy with cystic fibrosis demonstrates thickened airway secretions.
Which ion-transport defect is primary?
,A. Defective ENaC sodium reabsorption
B. Impaired CFTR chloride secretion
C. Overactive Na⁺/K⁺ ATPase
D. Mutated calcium-activated chloride channel
Correct Answer: B
Rationale: Cystic fibrosis is caused by mutations in the CFTR gene, producing a
defective chloride channel that prevents luminal chloride (and water) secretion, leading
to viscous mucus. ENaC (A) is hyperfunctional in CF, but it is secondary. Na⁺/K⁺ ATPase
(C) is normal. Calcium channels (D) are not mutated in CF.
3. A 45-year-old man with untreated hypertension develops left-ventricular wall
thickening. Which term best describes this change?
A. Dysplasia
B. Hypertrophy
C. Atrophy
D. Hyperplasia
Correct Answer: B
Rationale: Pressure overload increases cardiomyocyte sarcomeres in series, producing
concentric hypertrophy. Dysplasia (A) is atypical proliferation. Atrophy (C) is decreased
cell size. Hyperplasia (D) rarely occurs in adult cardiac muscle.
, 4. A 60-year-old smoker shows squamous epithelium replacing normal respiratory
columnar cells in a bronchial biopsy. This is an example of:
A. Anaplasia
B. Metaplasia
C. Dysplasia
D. Necrosis
Correct Answer: B
Rationale: Metaplasia is a reversible adaptive change from one mature cell type
(columnar) to another (squamous) in response to chronic irritation. Anaplasia (A)
implies malignancy. Dysplasia (C) is disordered growth, not a cell-type switch. Necrosis
(D) is cell death.
5. A 3-day-old neonate with trisomy 18 exhibits clenched fists and rocker-bottom
feet. Which genetic mechanism produced this karyotype?
A. Robertsonian translocation
B. Meiotic nondisjunction
C. Paracentric inversion
D. Gene amplification
, Correct Answer: B
Rationale: Full trisomy 18 (47,XX/XY,+18) results from meiotic nondisjunction,
increasing chromosome number. Robertsonian (A) involves chromosome fusion, seen
in trisomy 21 carriers. Inversions (C) and amplifications (D) do not change chromosome
count.
6. A 25-year-old woman with BRCA1 mutation has a 65 % lifetime risk of breast
cancer. Which pathophysiologic pathway is primarily disrupted?
A. Base-excision DNA repair
B. Homologous recombination repair
C. Mismatch repair
D. Nucleotide-excision repair
Correct Answer: B
Rationale: BRCA1 participates in double-strand break repair via homologous
recombination; loss leads to genomic instability. Mismatch repair (C) defects cause
Lynch syndrome. Base- and nucleotide-excision (A, D) handle single-strand damage.
7. A 30-year-old African-American man presents with painful vasculitic leg ulcers
and sensorimotor neuropathy. Genetic testing shows a single-base substitution
at codon 54 of the G6PD gene. Which mutation type is this?
Exam | ACTUAL EXAM | Questions & Verified Answers |
Latest Update – Chamberlain University
1. A 28-year-old woman with sustained aerobic training exhibits increased
mitochondrial density in skeletal muscle. Which cellular adaptation best explains
this change?
A. Hypertrophy
B. Hyperplasia
C. Metaplasia
D. Biogenesis
Correct Answer: D
Rationale: Mitochondrial biogenesis is the process by which new mitochondria are
formed, driven by transcriptional co-activators such as PGC-1α in response to
endurance exercise. Hypertrophy (A) refers to increased cell size, not organelle number.
Hyperplasia (B) is an increase in cell number, irrelevant here. Metaplasia (C) is a
reversible change of one differentiated cell type to another.
2. A 5-year-old boy with cystic fibrosis demonstrates thickened airway secretions.
Which ion-transport defect is primary?
,A. Defective ENaC sodium reabsorption
B. Impaired CFTR chloride secretion
C. Overactive Na⁺/K⁺ ATPase
D. Mutated calcium-activated chloride channel
Correct Answer: B
Rationale: Cystic fibrosis is caused by mutations in the CFTR gene, producing a
defective chloride channel that prevents luminal chloride (and water) secretion, leading
to viscous mucus. ENaC (A) is hyperfunctional in CF, but it is secondary. Na⁺/K⁺ ATPase
(C) is normal. Calcium channels (D) are not mutated in CF.
3. A 45-year-old man with untreated hypertension develops left-ventricular wall
thickening. Which term best describes this change?
A. Dysplasia
B. Hypertrophy
C. Atrophy
D. Hyperplasia
Correct Answer: B
Rationale: Pressure overload increases cardiomyocyte sarcomeres in series, producing
concentric hypertrophy. Dysplasia (A) is atypical proliferation. Atrophy (C) is decreased
cell size. Hyperplasia (D) rarely occurs in adult cardiac muscle.
, 4. A 60-year-old smoker shows squamous epithelium replacing normal respiratory
columnar cells in a bronchial biopsy. This is an example of:
A. Anaplasia
B. Metaplasia
C. Dysplasia
D. Necrosis
Correct Answer: B
Rationale: Metaplasia is a reversible adaptive change from one mature cell type
(columnar) to another (squamous) in response to chronic irritation. Anaplasia (A)
implies malignancy. Dysplasia (C) is disordered growth, not a cell-type switch. Necrosis
(D) is cell death.
5. A 3-day-old neonate with trisomy 18 exhibits clenched fists and rocker-bottom
feet. Which genetic mechanism produced this karyotype?
A. Robertsonian translocation
B. Meiotic nondisjunction
C. Paracentric inversion
D. Gene amplification
, Correct Answer: B
Rationale: Full trisomy 18 (47,XX/XY,+18) results from meiotic nondisjunction,
increasing chromosome number. Robertsonian (A) involves chromosome fusion, seen
in trisomy 21 carriers. Inversions (C) and amplifications (D) do not change chromosome
count.
6. A 25-year-old woman with BRCA1 mutation has a 65 % lifetime risk of breast
cancer. Which pathophysiologic pathway is primarily disrupted?
A. Base-excision DNA repair
B. Homologous recombination repair
C. Mismatch repair
D. Nucleotide-excision repair
Correct Answer: B
Rationale: BRCA1 participates in double-strand break repair via homologous
recombination; loss leads to genomic instability. Mismatch repair (C) defects cause
Lynch syndrome. Base- and nucleotide-excision (A, D) handle single-strand damage.
7. A 30-year-old African-American man presents with painful vasculitic leg ulcers
and sensorimotor neuropathy. Genetic testing shows a single-base substitution
at codon 54 of the G6PD gene. Which mutation type is this?
