TEST BANK For Functional Histology: A Text
and Colour Atlas (Paul R. Wheater et al.).
National Board–Style MCQs with 100%
Correct Answers and Explanations
,Topic 1: The Cell
1. A 4-year-old child presents with chronic diarrhea and failure to thrive. A biopsy of
the small intestine is performed. Electron microscopy of the luminal surface of the
enterocytes reveals a significantly reduced "fuzzy coat" or polysaccharide layer.
Which of the following best describes the likely function of the affected structure?
A. Facilitating active transport of sodium ions via ATP expenditure
B. Providing a template for the synthesis of messenger RNA
C. Cell recognition phenomena and adsorption of molecules to the cell surface
D. Generating ATP via the tricarboxylic acid cycle
E. Anchoring the contractile ring during cytokinesis
Correct Answer: C
Explanation: The "fuzzy coat" refers to the glycocalyx, a polysaccharide layer on the
external surface of the plasma membrane. It is involved in cell recognition, intercellular
adhesions, and the adsorption of molecules, and is particularly prominent in the small
intestine.
2. An 80-year-old male undergoes a routine autopsy. Examination of the cardiac
myocytes and neurons reveals numerous brown, granular cytoplasmic inclusions.
These "wear and tear" pigments are most likely the result of which process?
A. Accumulation of indigestible products within residual bodies
B. Excessive synthesis of steroid hormones in the smooth endoplasmic reticulum
C. Failure of the Golgi apparatus to package lysosomal enzymes
D. Rapid replication of mitochondrial DNA during the S-phase of the cell cycle
E. Accumulation of zymogen granules due to inhibited exocytosis
Correct Answer: A
Explanation: Lipofuscin granules are brown "wear and tear" pigments that accumulate in
long-lived cells with age. They represent residual bodies containing indigestible products of
autophagy or lysosomal digestion.
3. In a laboratory experiment, a cell is treated with a drug that specifically inhibits the
"sodium pump." As a result, the cell begins to swell. Which of the following
mechanisms is primarily responsible for the normal maintenance of this ionic
gradient, and what does it require?
A. Passive diffusion; requires a concentration gradient only
,B. Facilitated diffusion; requires specific carrier proteins but no energy
C. Active transport; requires the expenditure of energy in the form of ATP
D. Pinocytosis; requires the engulfment of small vacuoles
E. Exocytosis; requires fusion of vesicles with the plasma membrane
Correct Answer: C Explanation: The "sodium pump" is a classic example of active
transport. It operates against extreme concentration gradients and requires the expenditure
of energy provided by ATP.
4. A patient is diagnosed with a lysosomal storage disease. Histological analysis of
liver cells shows an abundance of primary lysosomes but a failure to form secondary
lysosomes. This suggests a defect in which of the following stages of endocytosis?
A. Formation of pseudopodia for particle recognition
B. Fusion of a phagosome with a primary lysosome
C. The discharge of undigested material via exocytosis
D. Synthesis of lysosomal enzymes on free ribosomes
E. Replication of the circular DNA strand within the lysosomal matrix
Correct Answer: B
Explanation: In the process of phagocytosis, a phagosome (or endocytotic vesicle) is
recognized and fuses with one or more primary lysosomes to form a secondary
lysosome, exposing the contents to hydrolytic enzymes.
5. A researcher observes a cell with a large, pale-stained nucleus containing a
prominent, dense nucleolus. This appearance most likely indicates which of the
following functional states?
A. The cell is in the G0 phase and is metabolically inactive
B. The cell is highly active in ribosomal RNA synthesis and protein production
C. The cell is undergoing apoptosis with condensed heterochromatin
D. The cell is specialized for lipid storage rather than protein synthesis
E. The cell is in the M phase of the cell cycle with visible chromosomes
Correct Answer: B
Explanation: Nucleoli are the sites of ribosomal RNA (rRNA) synthesis. Cells highly
active in protein synthesis typically have large nuclei with prominent nucleoli and abundant
euchromatin (the active portion of DNA).
, 6. Microscopic examination of a hormone-secreting cell from the adrenal cortex
reveals a prolific network of tubules and vesicles lacking attached ribosomes. This
organelle is primarily responsible for which of the following?
A. Transcription of DNA into messenger RNA
B. Synthesis of steroid hormones from cholesterol
C. Packaging of proteins into secretory granules
D. Synthesis of structural proteins for the cytoskeleton
E. Symmetrical distribution of chromatids during anaphase
Correct Answer: B
Explanation: Smooth endoplasmic reticulum (sER) is devoid of ribosomes and is the site
of lipid and cholesterol biosynthesis, as well as the synthesis of steroid hormones
derived from cholesterol.
7. During a study of the nuclear envelope, researchers use freeze-etching to visualize
"nuclear pores." Which statement best describes the relationship between the nuclear
envelope and the rest of the cell's membrane system?
A. It is a completely isolated compartment with no connections to other organelles
B. It is a specialized region of the endoplasmic reticulum, often studded with ribosomes
C. It is formed by the fusion of multiple Golgi cisternae during telophase
D. It is composed of a single layer of lipid-insoluble proteins
E. It is the site where translation of mRNA into polypeptide chains occurs
Correct Answer: B
Explanation: The nuclear envelope consists of two layers of membrane, the outer of which
is often studded with ribosomes and is continuous with the cisternae of the endoplasmic
reticulum.
8. In a cell specialized for the export of proteinaceous secretions, newly synthesized
proteins are transported from the rough ER to the Golgi apparatus. What is the
correct sequence of this "packaging" process?
A. Maturing face → Forming face → Secretory granule → Exocytosis
B. Transitional vesicle → Forming face → Maturing face → Secretory granule
C. Secretory granule → Maturing face → Forming face → Transitional vesicle
D. Forming face → Maturing face → Transitional vesicle → Rough ER
and Colour Atlas (Paul R. Wheater et al.).
National Board–Style MCQs with 100%
Correct Answers and Explanations
,Topic 1: The Cell
1. A 4-year-old child presents with chronic diarrhea and failure to thrive. A biopsy of
the small intestine is performed. Electron microscopy of the luminal surface of the
enterocytes reveals a significantly reduced "fuzzy coat" or polysaccharide layer.
Which of the following best describes the likely function of the affected structure?
A. Facilitating active transport of sodium ions via ATP expenditure
B. Providing a template for the synthesis of messenger RNA
C. Cell recognition phenomena and adsorption of molecules to the cell surface
D. Generating ATP via the tricarboxylic acid cycle
E. Anchoring the contractile ring during cytokinesis
Correct Answer: C
Explanation: The "fuzzy coat" refers to the glycocalyx, a polysaccharide layer on the
external surface of the plasma membrane. It is involved in cell recognition, intercellular
adhesions, and the adsorption of molecules, and is particularly prominent in the small
intestine.
2. An 80-year-old male undergoes a routine autopsy. Examination of the cardiac
myocytes and neurons reveals numerous brown, granular cytoplasmic inclusions.
These "wear and tear" pigments are most likely the result of which process?
A. Accumulation of indigestible products within residual bodies
B. Excessive synthesis of steroid hormones in the smooth endoplasmic reticulum
C. Failure of the Golgi apparatus to package lysosomal enzymes
D. Rapid replication of mitochondrial DNA during the S-phase of the cell cycle
E. Accumulation of zymogen granules due to inhibited exocytosis
Correct Answer: A
Explanation: Lipofuscin granules are brown "wear and tear" pigments that accumulate in
long-lived cells with age. They represent residual bodies containing indigestible products of
autophagy or lysosomal digestion.
3. In a laboratory experiment, a cell is treated with a drug that specifically inhibits the
"sodium pump." As a result, the cell begins to swell. Which of the following
mechanisms is primarily responsible for the normal maintenance of this ionic
gradient, and what does it require?
A. Passive diffusion; requires a concentration gradient only
,B. Facilitated diffusion; requires specific carrier proteins but no energy
C. Active transport; requires the expenditure of energy in the form of ATP
D. Pinocytosis; requires the engulfment of small vacuoles
E. Exocytosis; requires fusion of vesicles with the plasma membrane
Correct Answer: C Explanation: The "sodium pump" is a classic example of active
transport. It operates against extreme concentration gradients and requires the expenditure
of energy provided by ATP.
4. A patient is diagnosed with a lysosomal storage disease. Histological analysis of
liver cells shows an abundance of primary lysosomes but a failure to form secondary
lysosomes. This suggests a defect in which of the following stages of endocytosis?
A. Formation of pseudopodia for particle recognition
B. Fusion of a phagosome with a primary lysosome
C. The discharge of undigested material via exocytosis
D. Synthesis of lysosomal enzymes on free ribosomes
E. Replication of the circular DNA strand within the lysosomal matrix
Correct Answer: B
Explanation: In the process of phagocytosis, a phagosome (or endocytotic vesicle) is
recognized and fuses with one or more primary lysosomes to form a secondary
lysosome, exposing the contents to hydrolytic enzymes.
5. A researcher observes a cell with a large, pale-stained nucleus containing a
prominent, dense nucleolus. This appearance most likely indicates which of the
following functional states?
A. The cell is in the G0 phase and is metabolically inactive
B. The cell is highly active in ribosomal RNA synthesis and protein production
C. The cell is undergoing apoptosis with condensed heterochromatin
D. The cell is specialized for lipid storage rather than protein synthesis
E. The cell is in the M phase of the cell cycle with visible chromosomes
Correct Answer: B
Explanation: Nucleoli are the sites of ribosomal RNA (rRNA) synthesis. Cells highly
active in protein synthesis typically have large nuclei with prominent nucleoli and abundant
euchromatin (the active portion of DNA).
, 6. Microscopic examination of a hormone-secreting cell from the adrenal cortex
reveals a prolific network of tubules and vesicles lacking attached ribosomes. This
organelle is primarily responsible for which of the following?
A. Transcription of DNA into messenger RNA
B. Synthesis of steroid hormones from cholesterol
C. Packaging of proteins into secretory granules
D. Synthesis of structural proteins for the cytoskeleton
E. Symmetrical distribution of chromatids during anaphase
Correct Answer: B
Explanation: Smooth endoplasmic reticulum (sER) is devoid of ribosomes and is the site
of lipid and cholesterol biosynthesis, as well as the synthesis of steroid hormones
derived from cholesterol.
7. During a study of the nuclear envelope, researchers use freeze-etching to visualize
"nuclear pores." Which statement best describes the relationship between the nuclear
envelope and the rest of the cell's membrane system?
A. It is a completely isolated compartment with no connections to other organelles
B. It is a specialized region of the endoplasmic reticulum, often studded with ribosomes
C. It is formed by the fusion of multiple Golgi cisternae during telophase
D. It is composed of a single layer of lipid-insoluble proteins
E. It is the site where translation of mRNA into polypeptide chains occurs
Correct Answer: B
Explanation: The nuclear envelope consists of two layers of membrane, the outer of which
is often studded with ribosomes and is continuous with the cisternae of the endoplasmic
reticulum.
8. In a cell specialized for the export of proteinaceous secretions, newly synthesized
proteins are transported from the rough ER to the Golgi apparatus. What is the
correct sequence of this "packaging" process?
A. Maturing face → Forming face → Secretory granule → Exocytosis
B. Transitional vesicle → Forming face → Maturing face → Secretory granule
C. Secretory granule → Maturing face → Forming face → Transitional vesicle
D. Forming face → Maturing face → Transitional vesicle → Rough ER
