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 is studying a human cell in which the DNA content of the
nucleus is normal, but a mutation prevents proper packaging of DNA
around histone proteins. Which cellular process would most directly be
impaired?
A. Formation of ribosomes in the nucleolus
B. Organization and regulation of chromatin
C. Translation of messenger RNA into protein
D. Degradation of proteins in lysosomes
,Correct Answer: B. Organization and regulation of chromatin
Rationale: DNA is organized into chromatin by association with histone
proteins, allowing the genome to be compacted and its accessibility to
be regulated. Option A is incorrect because ribosome production
primarily occurs in the nucleolus and is not the direct consequence of
defective histone packaging. Option C describes translation, which
occurs on ribosomes in the cytoplasm or rough endoplasmic reticulum.
Option D refers to lysosomal degradation, a cellular housekeeping
process unrelated to chromatin organization.
Question 2
A somatic cell acquires a mutation that causes inappropriate activation
of a gene controlling cell proliferation. Which consequence is most likely
if the abnormal gene expression persists?
A. Permanent suppression of protein synthesis
B. Uncontrolled cellular proliferation
C. Immediate lysosomal destruction of the cell
D. Complete cessation of mitochondrial activity
Correct Answer: B. Uncontrolled cellular proliferation
Rationale: Genes regulating cell growth and proliferation must be
appropriately controlled; persistent abnormal activation can drive
excessive cellular proliferation. Option A is incorrect because
inappropriate activation of a proliferative gene does not inherently stop
protein synthesis. Option C is not a typical direct consequence of
altered proliferative signaling. Option D is also incorrect because
mitochondrial function may remain active during abnormal proliferation
and is often increased to meet cellular energy demands.
, Question 3
A cell contains misfolded proteins that cannot be safely incorporated
into functional protein complexes. Which cellular system is primarily
responsible for recognizing and selectively degrading many damaged or
abnormal cytosolic proteins?
A. Proteasome system
B. Extracellular matrix
C. Golgi apparatus
D. Nucleolus
Correct Answer: A. Proteasome system
Rationale: The ubiquitin-proteasome system is an important
mechanism for degrading damaged, misfolded, or otherwise targeted
intracellular proteins. Option B is incorrect because the extracellular
matrix provides structural and signaling support outside cells rather
than degrading cytosolic proteins. Option C is involved in modifying and
sorting proteins and lipids, not primarily in cytosolic protein
degradation. Option D is involved mainly in ribosomal RNA synthesis
and ribosome assembly.
Question 4
A hepatocyte is exposed to prolonged nutrient deprivation. It increases
delivery of cytoplasmic components to lysosomes for degradation and
recycling. Which process best explains this response?
A. Apoptosis
B. Autophagy
C. Exocytosis
D. Endocytosis
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 is studying a human cell in which the DNA content of the
nucleus is normal, but a mutation prevents proper packaging of DNA
around histone proteins. Which cellular process would most directly be
impaired?
A. Formation of ribosomes in the nucleolus
B. Organization and regulation of chromatin
C. Translation of messenger RNA into protein
D. Degradation of proteins in lysosomes
,Correct Answer: B. Organization and regulation of chromatin
Rationale: DNA is organized into chromatin by association with histone
proteins, allowing the genome to be compacted and its accessibility to
be regulated. Option A is incorrect because ribosome production
primarily occurs in the nucleolus and is not the direct consequence of
defective histone packaging. Option C describes translation, which
occurs on ribosomes in the cytoplasm or rough endoplasmic reticulum.
Option D refers to lysosomal degradation, a cellular housekeeping
process unrelated to chromatin organization.
Question 2
A somatic cell acquires a mutation that causes inappropriate activation
of a gene controlling cell proliferation. Which consequence is most likely
if the abnormal gene expression persists?
A. Permanent suppression of protein synthesis
B. Uncontrolled cellular proliferation
C. Immediate lysosomal destruction of the cell
D. Complete cessation of mitochondrial activity
Correct Answer: B. Uncontrolled cellular proliferation
Rationale: Genes regulating cell growth and proliferation must be
appropriately controlled; persistent abnormal activation can drive
excessive cellular proliferation. Option A is incorrect because
inappropriate activation of a proliferative gene does not inherently stop
protein synthesis. Option C is not a typical direct consequence of
altered proliferative signaling. Option D is also incorrect because
mitochondrial function may remain active during abnormal proliferation
and is often increased to meet cellular energy demands.
, Question 3
A cell contains misfolded proteins that cannot be safely incorporated
into functional protein complexes. Which cellular system is primarily
responsible for recognizing and selectively degrading many damaged or
abnormal cytosolic proteins?
A. Proteasome system
B. Extracellular matrix
C. Golgi apparatus
D. Nucleolus
Correct Answer: A. Proteasome system
Rationale: The ubiquitin-proteasome system is an important
mechanism for degrading damaged, misfolded, or otherwise targeted
intracellular proteins. Option B is incorrect because the extracellular
matrix provides structural and signaling support outside cells rather
than degrading cytosolic proteins. Option C is involved in modifying and
sorting proteins and lipids, not primarily in cytosolic protein
degradation. Option D is involved mainly in ribosomal RNA synthesis
and ribosome assembly.
Question 4
A hepatocyte is exposed to prolonged nutrient deprivation. It increases
delivery of cytoplasmic components to lysosomes for degradation and
recycling. Which process best explains this response?
A. Apoptosis
B. Autophagy
C. Exocytosis
D. Endocytosis
