1
A&P 1 101 MODULE 2 EXAM CELL BIOLOGY HISTOLOGY &
TISSUES 2026/2027 | Portage Learning | Graded A | 100%
Correct | Pass Guaranteed
[Section 1: Cell Structure & Organelles (Q1-18)]
Q1. A cell biologist isolates an organelle with a double membrane structure: an outer
smooth membrane and an inner membrane folded into cristae, containing its own
circular DNA and ribosomes. Which organelle is described?
A. Nucleus B. Golgi apparatus C. Mitochondrion D. Lysosome
Correct Answer: C
Rationale: Mitochondria possess a double membrane with inner cristae for electron
transport chain localization, contain mitochondrial DNA (mtDNA) and mitochondrial
ribosomes (55S), and are the site of ATP production via oxidative phosphorylation.
The nucleus also has a double membrane but lacks cristae and produces ATP;
lysosomes and Golgi lack DNA entirely.
Q2. A patient with chronic alcohol abuse shows hepatocyte swelling with
proliferation of smooth membranes involved in detoxification. Which organelle is
hypertrophying in response to ethanol metabolism?
A. Rough endoplasmic reticulum B. Smooth endoplasmic reticulum C. Golgi
apparatus D. Peroxisome
Correct Answer: B
,2
Rationale: The smooth endoplasmic reticulum (SER) contains cytochrome P450
enzymes that detoxify drugs, alcohol, and toxins; chronic alcohol exposure induces
SER proliferation (enzyme induction), increasing metabolic capacity but also
tolerance. The rough ER synthesizes proteins, not detoxification enzymes;
peroxisomes oxidize fatty acids and break down H₂O₂ but are not the primary alcohol
detoxification site.
Q3. During protein synthesis, a ribosome translating mRNA for a secreted hormone is
observed attached to the membrane of an organelle studded with ribosomes. This
organelle is the:
A. Smooth endoplasmic reticulum B. Rough endoplasmic reticulum C. Golgi
apparatus D. Mitochondrion
Correct Answer: B
Rationale: The rough endoplasmic reticulum (RER) is characterized by bound
ribosomes on its cytosolic surface and functions in synthesis, folding, and initial
modification of proteins destined for secretion, membrane insertion, or lysosomal
delivery. Free ribosomes synthesize cytosolic proteins; the Golgi modifies but does
not synthesize proteins; mitochondria have their own ribosomes for mtDNA-encoded
proteins.
Q4. A cell biologist observes an organelle containing acid hydrolases capable of
digesting macromolecules, carbohydrates, lipids, proteins, and nucleic acids at pH
~5.0. This organelle is the:
A. Peroxisome B. Lysosome C. Proteasome D. Mitochondrion
Correct Answer: B
Rationale: Lysosomes are membrane-bound vesicles containing acid hydrolases that
function optimally at acidic pH (~5.0), maintained by V-type H⁺-ATPase proton
pumps; they digest material via phagocytosis, autophagy, and autolysis. Peroxisomes
, 3
contain oxidases and catalase (not acid hydrolases); proteasomes degrade
ubiquitinated proteins in the cytosol at neutral pH.
Q5. A child with Tay-Sachs disease lacks hexosaminidase A activity. In which
organelle would this enzyme normally function to degrade GM2 ganglioside?
A. Peroxisome B. Lysosome C. Golgi apparatus D. Mitochondrion
Correct Answer: B
Rationale: Hexosaminidase A is a lysosomal acid hydrolase that degrades GM2
ganglioside; its deficiency causes accumulation of this substrate in lysosomes,
producing progressive neurodegeneration, cherry-red macula, and death by age 4.
Lysosomal storage diseases result from single enzyme deficiencies; peroxisomal
disorders (e.g., Zellweger syndrome) involve different metabolic pathways.
Q6. An electron micrograph reveals an organelle with flattened, membrane-bound
cisternae arranged in a stack with cis (forming), medial, and trans (maturing) faces.
Vesicles are visible budding from the trans face. This organelle is the:
A. Rough endoplasmic reticulum B. Golgi apparatus C. Lysosome D. Smooth
endoplasmic reticulum
Correct Answer: B
Rationale: The Golgi apparatus consists of cis, medial, and trans cisternae that
modify, package, and sort proteins and lipids received from the ER; vesicles bud from
the trans-Golgi network for delivery to lysosomes, secretory vesicles, or plasma
membrane. The RER and SER are tubular/reticular networks, not stacked cisternae;
lysosomes are individual vesicles.
A&P 1 101 MODULE 2 EXAM CELL BIOLOGY HISTOLOGY &
TISSUES 2026/2027 | Portage Learning | Graded A | 100%
Correct | Pass Guaranteed
[Section 1: Cell Structure & Organelles (Q1-18)]
Q1. A cell biologist isolates an organelle with a double membrane structure: an outer
smooth membrane and an inner membrane folded into cristae, containing its own
circular DNA and ribosomes. Which organelle is described?
A. Nucleus B. Golgi apparatus C. Mitochondrion D. Lysosome
Correct Answer: C
Rationale: Mitochondria possess a double membrane with inner cristae for electron
transport chain localization, contain mitochondrial DNA (mtDNA) and mitochondrial
ribosomes (55S), and are the site of ATP production via oxidative phosphorylation.
The nucleus also has a double membrane but lacks cristae and produces ATP;
lysosomes and Golgi lack DNA entirely.
Q2. A patient with chronic alcohol abuse shows hepatocyte swelling with
proliferation of smooth membranes involved in detoxification. Which organelle is
hypertrophying in response to ethanol metabolism?
A. Rough endoplasmic reticulum B. Smooth endoplasmic reticulum C. Golgi
apparatus D. Peroxisome
Correct Answer: B
,2
Rationale: The smooth endoplasmic reticulum (SER) contains cytochrome P450
enzymes that detoxify drugs, alcohol, and toxins; chronic alcohol exposure induces
SER proliferation (enzyme induction), increasing metabolic capacity but also
tolerance. The rough ER synthesizes proteins, not detoxification enzymes;
peroxisomes oxidize fatty acids and break down H₂O₂ but are not the primary alcohol
detoxification site.
Q3. During protein synthesis, a ribosome translating mRNA for a secreted hormone is
observed attached to the membrane of an organelle studded with ribosomes. This
organelle is the:
A. Smooth endoplasmic reticulum B. Rough endoplasmic reticulum C. Golgi
apparatus D. Mitochondrion
Correct Answer: B
Rationale: The rough endoplasmic reticulum (RER) is characterized by bound
ribosomes on its cytosolic surface and functions in synthesis, folding, and initial
modification of proteins destined for secretion, membrane insertion, or lysosomal
delivery. Free ribosomes synthesize cytosolic proteins; the Golgi modifies but does
not synthesize proteins; mitochondria have their own ribosomes for mtDNA-encoded
proteins.
Q4. A cell biologist observes an organelle containing acid hydrolases capable of
digesting macromolecules, carbohydrates, lipids, proteins, and nucleic acids at pH
~5.0. This organelle is the:
A. Peroxisome B. Lysosome C. Proteasome D. Mitochondrion
Correct Answer: B
Rationale: Lysosomes are membrane-bound vesicles containing acid hydrolases that
function optimally at acidic pH (~5.0), maintained by V-type H⁺-ATPase proton
pumps; they digest material via phagocytosis, autophagy, and autolysis. Peroxisomes
, 3
contain oxidases and catalase (not acid hydrolases); proteasomes degrade
ubiquitinated proteins in the cytosol at neutral pH.
Q5. A child with Tay-Sachs disease lacks hexosaminidase A activity. In which
organelle would this enzyme normally function to degrade GM2 ganglioside?
A. Peroxisome B. Lysosome C. Golgi apparatus D. Mitochondrion
Correct Answer: B
Rationale: Hexosaminidase A is a lysosomal acid hydrolase that degrades GM2
ganglioside; its deficiency causes accumulation of this substrate in lysosomes,
producing progressive neurodegeneration, cherry-red macula, and death by age 4.
Lysosomal storage diseases result from single enzyme deficiencies; peroxisomal
disorders (e.g., Zellweger syndrome) involve different metabolic pathways.
Q6. An electron micrograph reveals an organelle with flattened, membrane-bound
cisternae arranged in a stack with cis (forming), medial, and trans (maturing) faces.
Vesicles are visible budding from the trans face. This organelle is the:
A. Rough endoplasmic reticulum B. Golgi apparatus C. Lysosome D. Smooth
endoplasmic reticulum
Correct Answer: B
Rationale: The Golgi apparatus consists of cis, medial, and trans cisternae that
modify, package, and sort proteins and lipids received from the ER; vesicles bud from
the trans-Golgi network for delivery to lysosomes, secretory vesicles, or plasma
membrane. The RER and SER are tubular/reticular networks, not stacked cisternae;
lysosomes are individual vesicles.
