McCance & Huether’s Pathophysiology
The Biologic Basis for Disease in Adults
and Children
9th Edition
Author(s)Julia Rogers
TEST BANK
Q1. A 6-year-old child is diagnosed with a mitochondrial
DNA disorder after presenting with exercise intolerance,
lactic acidosis, and progressive neuromuscular weakness.
, The primary defect most directly impairs which cellular
function?
A. Packaging of proteins into secretory vesicles
B. Generation of ATP through oxidative phosphorylation
C. Digestion of intracellular debris by hydrolytic enzymes
D. Synthesis of membrane phospholipids
E. Assembly of ribosomal subunits
Correct Answer: B
Rationale:
• Clinical Clue: Exercise intolerance and lactic acidosis
indicate failure of aerobic energy production.
• Mechanism: Mitochondria generate ATP via the electron
transport chain and oxidative phosphorylation.
• Why the Correct Answer Is Right: Defective mitochondrial
respiration reduces ATP synthesis and forces cells to rely
on anaerobic glycolysis, producing excess lactate.
• Why the Other Options Are Wrong:
o A. The Golgi apparatus modifies and packages
proteins but does not generate ATP.
o C. Lysosomes degrade macromolecules and damaged
organelles.
o D. Smooth endoplasmic reticulum contributes to lipid
synthesis.
, o E. The nucleolus participates in ribosome assembly.
• Exam Trap: Lactic acidosis in the setting of muscle
weakness strongly suggests mitochondrial dysfunction.
• High-Yield Clinical Correlation: Organs with high metabolic
demands—brain, heart, and skeletal muscle—are
particularly vulnerable.
• Memory Anchor: Mitochondria are the cell’s “power
plants.”
Q2. A microbiologist identifies an organism that contains
DNA and ribosomes but lacks a membrane-bound nucleus
and reproduces by binary fission. Which structural feature
most directly distinguishes this organism from a human
cell?
A. Presence of a plasma membrane
B. Presence of ribosomes
C. Lack of membrane-bound organelles
D. Presence of chromosomal DNA
E. Ability to synthesize proteins
Correct Answer: C
Rationale:
• Clinical Clue: Binary fission and absence of a nucleus
define a prokaryote.
, • Mechanism: Prokaryotes lack internal membrane-bound
structures such as mitochondria, Golgi apparatus, and
nuclei.
• Why the Correct Answer Is Right: The absence of
membrane-bound organelles is the hallmark structural
difference from eukaryotic cells.
• Why the Other Options Are Wrong:
o A. All cells possess a plasma membrane.
o B. Ribosomes are present in both prokaryotes and
eukaryotes.
o D. Both cell types contain DNA.
o E. Both synthesize proteins.
• Exam Trap: Prokaryotes do contain ribosomes, just smaller
70S ribosomes.
• High-Yield Clinical Correlation: Many antibiotics exploit
differences between bacterial and human ribosomes.
• Memory Anchor: Prokaryotes are “pre-nucleus” cells.
Q3. A 52-year-old man develops jaundice and elevated
serum alkaline phosphatase after chronic alcohol use.
Hepatocyte biopsy demonstrates distention of stacked
The Biologic Basis for Disease in Adults
and Children
9th Edition
Author(s)Julia Rogers
TEST BANK
Q1. A 6-year-old child is diagnosed with a mitochondrial
DNA disorder after presenting with exercise intolerance,
lactic acidosis, and progressive neuromuscular weakness.
, The primary defect most directly impairs which cellular
function?
A. Packaging of proteins into secretory vesicles
B. Generation of ATP through oxidative phosphorylation
C. Digestion of intracellular debris by hydrolytic enzymes
D. Synthesis of membrane phospholipids
E. Assembly of ribosomal subunits
Correct Answer: B
Rationale:
• Clinical Clue: Exercise intolerance and lactic acidosis
indicate failure of aerobic energy production.
• Mechanism: Mitochondria generate ATP via the electron
transport chain and oxidative phosphorylation.
• Why the Correct Answer Is Right: Defective mitochondrial
respiration reduces ATP synthesis and forces cells to rely
on anaerobic glycolysis, producing excess lactate.
• Why the Other Options Are Wrong:
o A. The Golgi apparatus modifies and packages
proteins but does not generate ATP.
o C. Lysosomes degrade macromolecules and damaged
organelles.
o D. Smooth endoplasmic reticulum contributes to lipid
synthesis.
, o E. The nucleolus participates in ribosome assembly.
• Exam Trap: Lactic acidosis in the setting of muscle
weakness strongly suggests mitochondrial dysfunction.
• High-Yield Clinical Correlation: Organs with high metabolic
demands—brain, heart, and skeletal muscle—are
particularly vulnerable.
• Memory Anchor: Mitochondria are the cell’s “power
plants.”
Q2. A microbiologist identifies an organism that contains
DNA and ribosomes but lacks a membrane-bound nucleus
and reproduces by binary fission. Which structural feature
most directly distinguishes this organism from a human
cell?
A. Presence of a plasma membrane
B. Presence of ribosomes
C. Lack of membrane-bound organelles
D. Presence of chromosomal DNA
E. Ability to synthesize proteins
Correct Answer: C
Rationale:
• Clinical Clue: Binary fission and absence of a nucleus
define a prokaryote.
, • Mechanism: Prokaryotes lack internal membrane-bound
structures such as mitochondria, Golgi apparatus, and
nuclei.
• Why the Correct Answer Is Right: The absence of
membrane-bound organelles is the hallmark structural
difference from eukaryotic cells.
• Why the Other Options Are Wrong:
o A. All cells possess a plasma membrane.
o B. Ribosomes are present in both prokaryotes and
eukaryotes.
o D. Both cell types contain DNA.
o E. Both synthesize proteins.
• Exam Trap: Prokaryotes do contain ribosomes, just smaller
70S ribosomes.
• High-Yield Clinical Correlation: Many antibiotics exploit
differences between bacterial and human ribosomes.
• Memory Anchor: Prokaryotes are “pre-nucleus” cells.
Q3. A 52-year-old man develops jaundice and elevated
serum alkaline phosphatase after chronic alcohol use.
Hepatocyte biopsy demonstrates distention of stacked
