Robbins Basic Pathology
10th Edition
Author(s)Vinay Kumar; MBBS; MD;
FRCPath; Abul K. Abbas; MBBS and
Jon C. Aster; MD; PhD
Print ISBN: 9780323353175
,Question 1
A researcher isolates a newly identified human cell and observes that its
DNA is enclosed within a membrane-bound nucleus. Which cellular
component is primarily responsible for housing the genetic material and
regulating access to genes?
A. Lysosome
B. Nucleus
C. Peroxisome
D. Golgi apparatus
,Correct Answer: B. Nucleus
Rationale:
The nucleus contains the cell's genomic DNA and regulates gene
expression through control of transcription and RNA processing. The
lysosome primarily degrades intracellular material, the peroxisome
participates in oxidative reactions, and the Golgi apparatus modifies
and sorts proteins.
Question 2
A patient has a genetic defect that prevents proper folding of newly
synthesized proteins in the endoplasmic reticulum. Which cellular
process is most directly affected?
A. Protein quality control
B. DNA replication
C. Glycogen breakdown
D. Extracellular matrix degradation
Correct Answer: A. Protein quality control
Rationale:
The endoplasmic reticulum contains mechanisms that monitor protein
folding and help identify misfolded proteins for appropriate processing
or degradation. DNA replication occurs primarily in the nucleus,
glycogen breakdown occurs largely in the cytosol, and extracellular
matrix degradation is mediated by extracellular and lysosomal
proteolytic systems.
Question 3
, A toxin selectively disrupts the function of mitochondria in hepatocytes.
Which immediate cellular activity is most directly reduced?
A. ATP production by oxidative phosphorylation
B. DNA transcription by RNA polymerase
C. Protein sorting by the Golgi apparatus
D. Phagolysosomal degradation
Correct Answer: A. ATP production by oxidative phosphorylation
Rationale:
Mitochondria generate most cellular ATP through oxidative
phosphorylation, making them essential for energy-dependent cellular
processes. Nuclear transcription, Golgi protein sorting, and
phagolysosomal degradation occur through other cellular structures
and pathways.
Question 4
A cell exposed to a growth factor increases its rate of DNA synthesis and
prepares to divide. Which type of molecule most directly receives the
extracellular growth signal at the cell surface?
A. Ribosome
B. Receptor
C. Lysosomal enzyme
D. Structural collagen
Correct Answer: B. Receptor
Rationale:
Cell-surface receptors detect extracellular signals such as growth factors
and initiate intracellular signaling pathways that alter cellular behavior,
10th Edition
Author(s)Vinay Kumar; MBBS; MD;
FRCPath; Abul K. Abbas; MBBS and
Jon C. Aster; MD; PhD
Print ISBN: 9780323353175
,Question 1
A researcher isolates a newly identified human cell and observes that its
DNA is enclosed within a membrane-bound nucleus. Which cellular
component is primarily responsible for housing the genetic material and
regulating access to genes?
A. Lysosome
B. Nucleus
C. Peroxisome
D. Golgi apparatus
,Correct Answer: B. Nucleus
Rationale:
The nucleus contains the cell's genomic DNA and regulates gene
expression through control of transcription and RNA processing. The
lysosome primarily degrades intracellular material, the peroxisome
participates in oxidative reactions, and the Golgi apparatus modifies
and sorts proteins.
Question 2
A patient has a genetic defect that prevents proper folding of newly
synthesized proteins in the endoplasmic reticulum. Which cellular
process is most directly affected?
A. Protein quality control
B. DNA replication
C. Glycogen breakdown
D. Extracellular matrix degradation
Correct Answer: A. Protein quality control
Rationale:
The endoplasmic reticulum contains mechanisms that monitor protein
folding and help identify misfolded proteins for appropriate processing
or degradation. DNA replication occurs primarily in the nucleus,
glycogen breakdown occurs largely in the cytosol, and extracellular
matrix degradation is mediated by extracellular and lysosomal
proteolytic systems.
Question 3
, A toxin selectively disrupts the function of mitochondria in hepatocytes.
Which immediate cellular activity is most directly reduced?
A. ATP production by oxidative phosphorylation
B. DNA transcription by RNA polymerase
C. Protein sorting by the Golgi apparatus
D. Phagolysosomal degradation
Correct Answer: A. ATP production by oxidative phosphorylation
Rationale:
Mitochondria generate most cellular ATP through oxidative
phosphorylation, making them essential for energy-dependent cellular
processes. Nuclear transcription, Golgi protein sorting, and
phagolysosomal degradation occur through other cellular structures
and pathways.
Question 4
A cell exposed to a growth factor increases its rate of DNA synthesis and
prepares to divide. Which type of molecule most directly receives the
extracellular growth signal at the cell surface?
A. Ribosome
B. Receptor
C. Lysosomal enzyme
D. Structural collagen
Correct Answer: B. Receptor
Rationale:
Cell-surface receptors detect extracellular signals such as growth factors
and initiate intracellular signaling pathways that alter cellular behavior,
