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 examining a normal human cell and wants to identify
the structure that contains most of the cell's genetic material. Which
structure is primarily responsible?
A. Lysosome
B. Nucleus
C. Golgi apparatus
D. Peroxisome
Correct Answer: B. Nucleus
,Rationale: The nucleus contains the majority of the cell's genomic DNA
organized into chromosomes and regulates gene expression. Lysosomes
digest cellular material, the Golgi apparatus modifies and packages
proteins, and peroxisomes participate in oxidative reactions.
Question 2
A patient has a mutation that prevents a newly synthesized protein
from being properly transported to its intended intracellular location.
Which cellular system is most directly involved in determining the
protein's final destination?
A. Protein sorting and trafficking machinery
B. Glycolytic pathway
C. Mitochondrial electron transport chain
D. Cytoskeletal degradation system
Correct Answer: A. Protein sorting and trafficking machinery
Rationale: Proteins contain targeting signals that direct them to specific
cellular compartments, and intracellular trafficking machinery
recognizes these signals. Glycolysis and electron transport generate
energy, while cytoskeletal degradation does not primarily determine
protein localization.
Question 3
Which organelle is primarily responsible for degrading intracellular
proteins and damaged organelles through an acidic, enzyme-rich
environment?
A. Ribosome
B. Lysosome
, C. Nucleolus
D. Smooth endoplasmic reticulum
Correct Answer: B. Lysosome
Rationale: Lysosomes contain acid hydrolases that degrade proteins,
lipids, nucleic acids, and cellular debris delivered to them. Ribosomes
synthesize proteins, the nucleolus produces ribosomal components, and
the smooth endoplasmic reticulum has important roles in lipid synthesis
and detoxification.
Question 4
A cell requires a continuous supply of adenosine triphosphate (ATP) to
support active membrane transport. Which organelle generates most
ATP under normal aerobic conditions?
A. Golgi apparatus
B. Lysosome
C. Mitochondrion
D. Nucleus
Correct Answer: C. Mitochondrion
Rationale: Mitochondria generate most cellular ATP through oxidative
phosphorylation using the electron transport chain and ATP synthase.
The other organelles perform essential functions but are not the major
source of ATP production under aerobic conditions.
Question 5
A hepatocyte increases its production of a specific enzyme after
exposure to a hormone that activates intracellular signaling. Which