NU 606 / NU606 Advanced Pathophysiology Final Exam
Actual 2024/2025 with Detailed Rationales | 100%
Verified | Pass Guaranteed – A+ Graded
SECTION 1: Cellular & Molecular Pathophysiology
(Questions 1–12)
Q1: A mutation in the p53 tumor suppressor gene results in uncontrolled cellular
proliferation. Which cellular process is primarily disrupted?
A. DNA repair and cell cycle checkpoint control [CORRECT]
B. Telomerase activation
C. Growth factor signal amplification
D. Apoptosis inhibition only
Correct Answer: A
Rationale: Correct because p53 functions as the "guardian of the genome" by
initiating cell cycle arrest, DNA repair, or apoptosis in response to cellular stress; loss
of p53 function allows damaged cells to proliferate uncontrollably.
Q2: Which signal transduction pathway is most commonly hyperactivated in human
cancers?
A. cAMP-dependent pathway
B. Receptor tyrosine kinase/RAS/MAPK pathway [CORRECT]
C. G-protein coupled receptor pathway
D. JAK-STAT pathway only
Correct Answer: B
Rationale: Correct because the RTK-RAS-MAPK pathway regulates cell proliferation,
survival, and differentiation; mutations in RAS, BRAF, or receptor tyrosine kinases
drive oncogenesis in approximately 30% of all cancers.
Q3: A patient with cancer has chemotherapy-resistant tumor cells. Which
mechanism most likely contributes to multidrug resistance?
A. Increased drug uptake into cells
,B. Overexpression of P-glycoprotein (MDR1) efflux pump [CORRECT]
C. Decreased DNA repair capacity
D. Enhanced apoptosis signaling
Correct Answer: B
Rationale: Correct because P-glycoprotein, encoded by the MDR1 gene, is an
ATP-dependent efflux pump that actively transports chemotherapeutic agents out of
cells, reducing intracellular drug concentrations and conferring resistance.
Q4: Which molecular mechanism characterizes the transition from reversible to
irreversible cell injury?
A. Decreased intracellular calcium
B. Mitochondrial permeability transition pore opening and ATP depletion [CORRECT]
C. Increased intracellular pH
D. Enhanced protein synthesis
Correct Answer: B
Rationale: Correct because opening of the mitochondrial permeability transition pore
causes loss of mitochondrial membrane potential, cessation of oxidative
phosphorylation, and ATP depletion, committing the cell to death.
Q5: Epigenetic modifications that silence tumor suppressor genes without altering
the DNA sequence include:
A. Point mutations
B. DNA hypermethylation and histone deacetylation [CORRECT]
C. Chromosomal translocations
D. Gene duplications
Correct Answer: B
Rationale: Correct because DNA hypermethylation of CpG islands in promoter
regions and histone deacetylation compact chromatin, silencing tumor suppressor
gene expression without changing the underlying DNA sequence.
Q6: A patient has a genetic disorder caused by expansion of a trinucleotide repeat.
Which disease follows this mechanism?
A. Sickle cell anemia
B. Huntington's disease [CORRECT]
C. Cystic fibrosis
D. Hemophilia A
Correct Answer: B
, Rationale: Correct because Huntington's disease is caused by CAG trinucleotide
repeat expansion in the HTT gene, leading to polyglutamine tract expansion and
toxic gain-of-function in the huntingtin protein.
Q7: Which cellular process is characterized by controlled, energy-dependent
self-destruction without inflammation?
A. Necrosis
B. Apoptosis [CORRECT]
C. Autophagy
D. Pyroptosis
Correct Answer: B
Rationale: Correct because apoptosis is a programmed cell death pathway requiring
ATP, characterized by cell shrinkage, chromatin condensation, membrane blebbing,
and phagocytosis without triggering inflammation.
Q8: A mutation in the BRCA1 gene increases susceptibility to breast and ovarian
cancer. Which cellular function is primarily impaired?
A. Cell cycle regulation
B. Homologous recombination DNA repair [CORRECT]
C. Telomere maintenance
D. Growth factor signaling
Correct Answer: B
Rationale: Correct because BRCA1 is essential for homologous recombination repair
of DNA double-strand breaks; loss of function results in genomic instability and
increased cancer susceptibility.
Q9: Which oncogene is most commonly activated in pancreatic adenocarcinoma?
A. MYC
B. KRAS [CORRECT]
C. EGFR
D. HER2
Correct Answer: B
Rationale: Correct because KRAS mutations are present in over 90% of pancreatic
ductal adenocarcinomas, constitutively activating downstream signaling pathways
that drive proliferation and survival.
Actual 2024/2025 with Detailed Rationales | 100%
Verified | Pass Guaranteed – A+ Graded
SECTION 1: Cellular & Molecular Pathophysiology
(Questions 1–12)
Q1: A mutation in the p53 tumor suppressor gene results in uncontrolled cellular
proliferation. Which cellular process is primarily disrupted?
A. DNA repair and cell cycle checkpoint control [CORRECT]
B. Telomerase activation
C. Growth factor signal amplification
D. Apoptosis inhibition only
Correct Answer: A
Rationale: Correct because p53 functions as the "guardian of the genome" by
initiating cell cycle arrest, DNA repair, or apoptosis in response to cellular stress; loss
of p53 function allows damaged cells to proliferate uncontrollably.
Q2: Which signal transduction pathway is most commonly hyperactivated in human
cancers?
A. cAMP-dependent pathway
B. Receptor tyrosine kinase/RAS/MAPK pathway [CORRECT]
C. G-protein coupled receptor pathway
D. JAK-STAT pathway only
Correct Answer: B
Rationale: Correct because the RTK-RAS-MAPK pathway regulates cell proliferation,
survival, and differentiation; mutations in RAS, BRAF, or receptor tyrosine kinases
drive oncogenesis in approximately 30% of all cancers.
Q3: A patient with cancer has chemotherapy-resistant tumor cells. Which
mechanism most likely contributes to multidrug resistance?
A. Increased drug uptake into cells
,B. Overexpression of P-glycoprotein (MDR1) efflux pump [CORRECT]
C. Decreased DNA repair capacity
D. Enhanced apoptosis signaling
Correct Answer: B
Rationale: Correct because P-glycoprotein, encoded by the MDR1 gene, is an
ATP-dependent efflux pump that actively transports chemotherapeutic agents out of
cells, reducing intracellular drug concentrations and conferring resistance.
Q4: Which molecular mechanism characterizes the transition from reversible to
irreversible cell injury?
A. Decreased intracellular calcium
B. Mitochondrial permeability transition pore opening and ATP depletion [CORRECT]
C. Increased intracellular pH
D. Enhanced protein synthesis
Correct Answer: B
Rationale: Correct because opening of the mitochondrial permeability transition pore
causes loss of mitochondrial membrane potential, cessation of oxidative
phosphorylation, and ATP depletion, committing the cell to death.
Q5: Epigenetic modifications that silence tumor suppressor genes without altering
the DNA sequence include:
A. Point mutations
B. DNA hypermethylation and histone deacetylation [CORRECT]
C. Chromosomal translocations
D. Gene duplications
Correct Answer: B
Rationale: Correct because DNA hypermethylation of CpG islands in promoter
regions and histone deacetylation compact chromatin, silencing tumor suppressor
gene expression without changing the underlying DNA sequence.
Q6: A patient has a genetic disorder caused by expansion of a trinucleotide repeat.
Which disease follows this mechanism?
A. Sickle cell anemia
B. Huntington's disease [CORRECT]
C. Cystic fibrosis
D. Hemophilia A
Correct Answer: B
, Rationale: Correct because Huntington's disease is caused by CAG trinucleotide
repeat expansion in the HTT gene, leading to polyglutamine tract expansion and
toxic gain-of-function in the huntingtin protein.
Q7: Which cellular process is characterized by controlled, energy-dependent
self-destruction without inflammation?
A. Necrosis
B. Apoptosis [CORRECT]
C. Autophagy
D. Pyroptosis
Correct Answer: B
Rationale: Correct because apoptosis is a programmed cell death pathway requiring
ATP, characterized by cell shrinkage, chromatin condensation, membrane blebbing,
and phagocytosis without triggering inflammation.
Q8: A mutation in the BRCA1 gene increases susceptibility to breast and ovarian
cancer. Which cellular function is primarily impaired?
A. Cell cycle regulation
B. Homologous recombination DNA repair [CORRECT]
C. Telomere maintenance
D. Growth factor signaling
Correct Answer: B
Rationale: Correct because BRCA1 is essential for homologous recombination repair
of DNA double-strand breaks; loss of function results in genomic instability and
increased cancer susceptibility.
Q9: Which oncogene is most commonly activated in pancreatic adenocarcinoma?
A. MYC
B. KRAS [CORRECT]
C. EGFR
D. HER2
Correct Answer: B
Rationale: Correct because KRAS mutations are present in over 90% of pancreatic
ductal adenocarcinomas, constitutively activating downstream signaling pathways
that drive proliferation and survival.
