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 analyzes a human cell with a normal diploid
chromosome complement. Which cellular structure contains the
majority of the cell's genomic DNA?
A. Lysosome
B. Nucleus
C. Golgi apparatus
D. Peroxisome
,Correct Answer: B. Nucleus
Rationale: The nucleus contains the cell's primary genome organized
into chromosomes. Lysosomes and the Golgi apparatus do not contain
genomic DNA, while mitochondria contain only a small, separate
mitochondrial genome.
Question 2
A mutation alters the promoter region of a gene, preventing
transcription factors from binding effectively. Which cellular process is
most directly impaired?
A. DNA replication
B. mRNA transcription
C. Protein folding
D. Lysosomal degradation
Correct Answer: B. mRNA transcription
Rationale: Promoter regions regulate initiation of transcription, so
impaired transcription-factor binding reduces formation of the
corresponding RNA transcript. DNA replication, protein folding, and
lysosomal degradation occur through different mechanisms.
Question 3
A patient has a hereditary disorder caused by a mutation that results
in an abnormal amino acid sequence within a structural protein.
Which process best explains how the DNA alteration produces the
abnormal protein?
A. DNA mutation changes RNA coding information used during
translation
B. Lysosomes directly convert DNA into protein
, C. Mitochondria remove the mutation before translation
D. The extracellular matrix translates DNA into protein
Correct Answer: A. DNA mutation changes RNA coding information
used during translation
Rationale: A DNA sequence change can alter the RNA transcript and
consequently the amino acid sequence produced during translation.
Lysosomes and extracellular matrix do not translate DNA, and
mitochondria do not routinely remove nuclear DNA mutations.
Question 4
A cell continuously removes damaged or unwanted proteins to
maintain normal intracellular function. Which organelle is primarily
responsible for degrading many proteins that have been tagged for
destruction?
A. Proteasome
B. Ribosome
C. Centriole
D. Nucleolus
Correct Answer: A. Proteasome
Rationale: The ubiquitin-proteasome system selectively degrades
many intracellular proteins after they are tagged with ubiquitin.
Ribosomes synthesize proteins, centrioles participate in cytoskeletal
organization, and the nucleolus is involved in ribosomal RNA
production and ribosome assembly.
Question 5
A secretory protein is synthesized by a cell and must be transported
through the secretory pathway before being released outside the cell.
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 analyzes a human cell with a normal diploid
chromosome complement. Which cellular structure contains the
majority of the cell's genomic DNA?
A. Lysosome
B. Nucleus
C. Golgi apparatus
D. Peroxisome
,Correct Answer: B. Nucleus
Rationale: The nucleus contains the cell's primary genome organized
into chromosomes. Lysosomes and the Golgi apparatus do not contain
genomic DNA, while mitochondria contain only a small, separate
mitochondrial genome.
Question 2
A mutation alters the promoter region of a gene, preventing
transcription factors from binding effectively. Which cellular process is
most directly impaired?
A. DNA replication
B. mRNA transcription
C. Protein folding
D. Lysosomal degradation
Correct Answer: B. mRNA transcription
Rationale: Promoter regions regulate initiation of transcription, so
impaired transcription-factor binding reduces formation of the
corresponding RNA transcript. DNA replication, protein folding, and
lysosomal degradation occur through different mechanisms.
Question 3
A patient has a hereditary disorder caused by a mutation that results
in an abnormal amino acid sequence within a structural protein.
Which process best explains how the DNA alteration produces the
abnormal protein?
A. DNA mutation changes RNA coding information used during
translation
B. Lysosomes directly convert DNA into protein
, C. Mitochondria remove the mutation before translation
D. The extracellular matrix translates DNA into protein
Correct Answer: A. DNA mutation changes RNA coding information
used during translation
Rationale: A DNA sequence change can alter the RNA transcript and
consequently the amino acid sequence produced during translation.
Lysosomes and extracellular matrix do not translate DNA, and
mitochondria do not routinely remove nuclear DNA mutations.
Question 4
A cell continuously removes damaged or unwanted proteins to
maintain normal intracellular function. Which organelle is primarily
responsible for degrading many proteins that have been tagged for
destruction?
A. Proteasome
B. Ribosome
C. Centriole
D. Nucleolus
Correct Answer: A. Proteasome
Rationale: The ubiquitin-proteasome system selectively degrades
many intracellular proteins after they are tagged with ubiquitin.
Ribosomes synthesize proteins, centrioles participate in cytoskeletal
organization, and the nucleolus is involved in ribosomal RNA
production and ribosome assembly.
Question 5
A secretory protein is synthesized by a cell and must be transported
through the secretory pathway before being released outside the cell.
