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 examines a normal human somatic cell and asks what
structure contains the majority of the cell's genetic information and
directs long-term cellular function. Which structure is primarily
responsible?
A. Lysosome
B. Nucleus
C. Golgi apparatus
D. Peroxisome
,Correct Answer: B. Nucleus
Rationale: The nucleus contains most of the cell's DNA and regulates
gene expression, replication, and many aspects of cellular function.
Lysosomes primarily digest intracellular material, the Golgi apparatus
modifies and sorts proteins, and peroxisomes participate in oxidative
reactions and lipid metabolism.
Question 2
A cell is exposed to a mild, reversible stress that causes it to increase in
size because of increased synthesis of structural proteins and
organelles. Which cellular response best describes this change?
A. Hypertrophy
B. Hyperplasia
C. Atrophy
D. Metaplasia
Correct Answer: A. Hypertrophy
Rationale: Hypertrophy is an increase in cell size that results in
enlargement of the affected tissue or organ. Hyperplasia is an increase
in cell number, atrophy is a decrease in cell size and functional capacity,
and metaplasia is a reversible change from one differentiated cell type
to another.
Question 3
A mutation occurs in a gene that codes for a protein required for DNA
replication. Which cellular function is most directly threatened?
A. Maintenance and transmission of genetic information
B. Protein packaging in the Golgi apparatus
, C. Digestion of damaged organelles by lysosomes
D. Oxidation of fatty acids in peroxisomes
Correct Answer: A. Maintenance and transmission of genetic
information
Rationale: DNA replication is essential for maintaining and transmitting
the genome during cell division. Golgi function is involved in protein
processing and trafficking, lysosomes digest cellular components, and
peroxisomes participate in oxidative metabolism rather than DNA
replication.
Question 4
A patient develops a disorder caused by accumulation of an abnormal
protein that cannot be properly folded and degraded. Which cellular
housekeeping process is most directly involved?
A. Protein quality control and degradation
B. DNA transcription
C. Extracellular matrix synthesis
D. Cell-cell recognition by adhesion molecules
Correct Answer: A. Protein quality control and degradation
Rationale: Cells continuously synthesize, fold, monitor, and remove
proteins to maintain cellular homeostasis. Failure of protein quality-
control mechanisms can result in accumulation of abnormal proteins
and cellular dysfunction. Transcription produces RNA from DNA,
extracellular matrix synthesis occurs outside the cell, and adhesion
molecules primarily mediate interactions between cells or with the
matrix.