The Biologic Basis for Disease in Adults and Children
9th Edition
• Author(s)Julia Rogers
TEST BANK
McCance & Huether — Pathophysiology, 9th Ed. — Chapter 1:
Cellular Biology.
Chapter Reference: Cellular Biology — Prokaryotes and
Eukaryotes
Stem: A hospitalized patient’s blood culture grows bacteria that
lack a nuclear membrane and 70S ribosomes. Which feature
most reliably distinguishes these organisms from the patient’s
own cells?
Options:
A. Presence of membrane-bound organelles
B. Lack of a true nucleus
C. Presence of histone-bound DNA
D. Presence of linear chromosomes
Correct Answer: B
Rationales:
, • Correct (B): Prokaryotes characteristically lack a true
(membrane-bound) nucleus; their genetic material is not
enclosed by a nuclear membrane, distinguishing them
from eukaryotic human cells.
• Incorrect (A): Membrane-bound organelles are absent in
prokaryotes, but this is broader; the nuclear membrane
specifically differentiates them.
• Incorrect (C): Histone-bound DNA is typical of eukaryotes;
prokaryotes generally lack histones, but some have
histone-like proteins—less reliable as a single
distinguishing feature.
• Incorrect (D): Linear chromosomes are characteristic of
eukaryotes; many prokaryotes have circular chromosomes,
but chromosome shape alone is less immediately
diagnostic.
Teaching Point: Prokaryotes lack a membrane-bound
nucleus — the clearest cellular distinction.
Stem Rules: Clear, concise clinical stem; avoids negatives;
mechanism-focused.
2.
Chapter Reference: Cellular Biology — Cellular Functions
(Homeostasis)
Stem: A patient with dehydration has concentrated plasma and
decreased tissue perfusion. Which cellular process is primarily
,threatened first by reduced extracellular volume?
Options:
A. Oxidative phosphorylation
B. Protein synthesis
C. Membrane receptor synthesis
D. Phagocytosis
Correct Answer: A
Rationales:
• Correct (A): Reduced perfusion decreases oxygen delivery
to cells, impairing oxidative phosphorylation in
mitochondria and rapidly reducing ATP production.
• Incorrect (B): Protein synthesis depends on ATP and will be
affected downstream, but oxidative phosphorylation fails
earlier.
• Incorrect (C): Membrane receptor synthesis is energy-
dependent and affected later; not the immediate primary
threat.
• Incorrect (D): Phagocytosis is ATP-dependent and may be
impaired, but energy failure from reduced oxidative
phosphorylation is the primary initial event.
Teaching Point: Oxygen delivery loss first impairs oxidative
phosphorylation, dropping cellular ATP.
Stem Rules: Short clinical vignette linking systemic
perfusion to cellular metabolism.
, 3.
Chapter Reference: Cellular Biology — Structure and Function
of Cellular Components (Mitochondria)
Stem: A patient’s muscle biopsy shows ragged-red fibers and a
maternally inherited myopathy. Which organelle dysfunction
best explains these findings?
Options:
A. Lysosomal enzyme deficiency
B. Mitochondrial oxidative phosphorylation defect
C. Dysfunctional rough endoplasmic reticulum
D. Defective Golgi glycosylation
Correct Answer: B
Rationales:
• Correct (B): Ragged-red fibers and maternal inheritance
point to mitochondrial DNA mutations that impair
oxidative phosphorylation, causing muscle weakness and
lactic acidosis.
• Incorrect (A): Lysosomal enzyme deficiencies produce
storage disorders with different histology and inheritance
patterns.
• Incorrect (C): Rough ER dysfunction affects protein
synthesis broadly, not specifically maternal inheritance or
ragged-red fibers.
• Incorrect (D): Golgi glycosylation defects cause congenital
disorders of glycosylation with different clinical features.