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 how a cell maintains the information needed
to produce its proteins and regulate its functions. Which cellular
structure contains most of the cell's genomic DNA?
A. Lysosome
B. Nucleus
C. Golgi apparatus
D. Peroxisome
,Correct Answer: B. Nucleus
Rationale: The nucleus contains most of the cell's genomic DNA and
provides the major site for DNA replication and transcription.
Lysosomes digest intracellular material, the Golgi apparatus modifies
and sorts proteins, and peroxisomes participate in oxidative reactions
and lipid metabolism.
Question 2
A patient has a mutation affecting a gene that normally encodes a
structural protein. Which consequence is most directly expected from
a mutation that alters the DNA sequence of that gene?
A. Altered production or structure of the encoded protein
B. Immediate destruction of all cellular membranes
C. Complete inhibition of mitochondrial ATP synthesis
D. Permanent activation of every cellular receptor
Correct Answer: A. Altered production or structure of the encoded
protein
Rationale: Genetic information is expressed through RNA and
ultimately determines protein production and structure, so a mutation
can change the amount or function of a protein. The other choices
describe effects that are not universal consequences of a single gene
mutation.
Question 3
A cell is synthesizing a secreted protein that will be released into the
extracellular space. Which organelle is primarily responsible for
synthesizing proteins destined for secretion?
, A. Smooth endoplasmic reticulum
B. Rough endoplasmic reticulum
C. Lysosome
D. Peroxisome
Correct Answer: B. Rough endoplasmic reticulum
Rationale: Ribosomes attached to the rough endoplasmic reticulum
synthesize proteins destined for secretion, insertion into membranes,
or delivery to certain organelles. The smooth endoplasmic reticulum is
involved in lipid synthesis and other functions, lysosomes digest
cellular material, and peroxisomes participate in oxidative
metabolism.
Question 4
Which organelle is most directly responsible for generating much of
the ATP required to support cellular activities?
A. Mitochondrion
B. Golgi apparatus
C. Lysosome
D. Nucleus
Correct Answer: A. Mitochondrion
Rationale: Mitochondria generate most cellular ATP through oxidative
phosphorylation and also participate in other metabolic processes.
The Golgi apparatus processes and sorts proteins, lysosomes degrade
materials, and the nucleus primarily stores genetic information and
regulates gene expression.
Question 5
A cell must rapidly increase its functional activity in response to a