Walden University NURS 6501 Exam 1 (docx) |
2026/2027 | Cellular Biology & Cellular Injury Q&A |
Nursing
1. What structural feature gives the plasma membrane selective permeability?
A) A phospholipid bilayer with embedded proteins
B) A rigid cellulose wall
C) A freely permeable protein sheet
D) A nuclear envelope
Correct Answer: A phospholipid bilayer with embedded proteins
Rationale: Its hydrophobic core limits passage of charged solutes while transport proteins regulate
specific movement. In cell membrane, recognizing this mechanism helps distinguish the underlying
process from superficially similar findings and connects molecular changes with tissue-level
consequences. The alternative choices describe different structures, pathways, or responses and
therefore do not account for the specific mechanism tested in this scenario.
2. Which process moves a solute down its concentration gradient without ATP through a carrier?
A) Primary active transport
B) Facilitated diffusion
C) Endocytosis
D) Exocytosis
Correct Answer: Facilitated diffusion
Rationale: A carrier permits passive movement of a specific solute without directly consuming
cellular energy. In membrane transport, recognizing this mechanism helps distinguish the underlying
process from superficially similar findings and connects molecular changes with tissue-level
consequences. The alternative choices describe different structures, pathways, or responses and
therefore do not account for the specific mechanism tested in this scenario.
3. How does the sodium–potassium ATPase normally move ions per ATP hydrolyzed?
A) Two sodium ions out and three potassium ions in
B) Three sodium ions in and two potassium ions out
C) Three sodium ions out and two potassium ions in
D) Equal sodium and potassium ions outward
,Correct Answer: Three sodium ions out and two potassium ions in
Rationale: The electrogenic pump preserves gradients essential for resting membrane potential and
cell volume. In ion gradients, recognizing this mechanism helps distinguish the underlying process
from superficially similar findings and connects molecular changes with tissue-level consequences.
The alternative choices describe different structures, pathways, or responses and therefore do not
account for the specific mechanism tested in this scenario.
4. A red blood cell placed in a markedly hypotonic solution is expected to undergo what change?
A) Water efflux and shrinkage
B) No net water movement
C) Immediate protein synthesis
D) Water influx and swelling
Correct Answer: Water influx and swelling
Rationale: Water moves toward the compartment with higher effective solute concentration across
its membrane. In osmosis, recognizing this mechanism helps distinguish the underlying process
from superficially similar findings and connects molecular changes with tissue-level consequences.
The alternative choices describe different structures, pathways, or responses and therefore do not
account for the specific mechanism tested in this scenario.
5. Which organelle produces most ATP during aerobic respiration?
A) Mitochondrion
B) Lysosome
C) Golgi apparatus
D) Nucleolus
Correct Answer: Mitochondrion
Rationale: Oxidative phosphorylation across the inner mitochondrial membrane supplies most ATP
in oxygenated cells. In mitochondria, recognizing this mechanism helps distinguish the underlying
process from superficially similar findings and connects molecular changes with tissue-level
consequences. The alternative choices describe different structures, pathways, or responses and
therefore do not account for the specific mechanism tested in this scenario.
6. A cell synthesizing large quantities of secreted proteins would have abundant which structure?
A) Smooth endoplasmic reticulum only
B) Rough endoplasmic reticulum
C) Peroxisomes only
,D) Centrioles only
Correct Answer: Rough endoplasmic reticulum
Rationale: Ribosome-studded rough endoplasmic reticulum translates proteins destined for
secretion and membranes. In rough er, recognizing this mechanism helps distinguish the underlying
process from superficially similar findings and connects molecular changes with tissue-level
consequences. The alternative choices describe different structures, pathways, or responses and
therefore do not account for the specific mechanism tested in this scenario.
7. Following synthesis in rough endoplasmic reticulum, where are secretory proteins modified and
sorted?
A) Nucleus
B) Peroxisome
C) Golgi apparatus
D) Mitochondrial matrix
Correct Answer: Golgi apparatus
Rationale: The Golgi modifies and packages proteins for their appropriate intracellular or
extracellular destinations. In golgi, recognizing this mechanism helps distinguish the underlying
process from superficially similar findings and connects molecular changes with tissue-level
consequences. The alternative choices describe different structures, pathways, or responses and
therefore do not account for the specific mechanism tested in this scenario.
8. Loss of lysosomal membrane integrity most directly causes which consequence?
A) Increased nuclear DNA replication
B) Accelerated ATP synthesis
C) Enhanced ribosome assembly
D) Release of hydrolytic enzymes into cytosol
Correct Answer: Release of hydrolytic enzymes into cytosol
Rationale: Lysosomal hydrolases digest macromolecules and can contribute to cellular destruction
when released. In lysosomes, recognizing this mechanism helps distinguish the underlying process
from superficially similar findings and connects molecular changes with tissue-level consequences.
The alternative choices describe different structures, pathways, or responses and therefore do not
account for the specific mechanism tested in this scenario.
9. Which function is especially associated with peroxisomes?
A) Oxidation of very-long-chain fatty acids
B) Assembly of ribosomal RNA
, C) Packaging of secreted insulin
D) Spindle fiber formation
Correct Answer: Oxidation of very-long-chain fatty acids
Rationale: Peroxisomes contain oxidative enzymes and catalase that process selected lipids and
hydrogen peroxide. In peroxisomes, recognizing this mechanism helps distinguish the underlying
process from superficially similar findings and connects molecular changes with tissue-level
consequences. The alternative choices describe different structures, pathways, or responses and
therefore do not account for the specific mechanism tested in this scenario.
10. What cellular component is primarily responsible for mitotic spindle formation?
A) Collagen fibers
B) Microtubules
C) Plasma proteins
D) Glycogen granules
Correct Answer: Microtubules
Rationale: Tubulin-based microtubules organize chromosomes during mitosis and also support
intracellular transport. In cytoskeleton, recognizing this mechanism helps distinguish the underlying
process from superficially similar findings and connects molecular changes with tissue-level
consequences. The alternative choices describe different structures, pathways, or responses and
therefore do not account for the specific mechanism tested in this scenario.
11. During DNA replication, which principle preserves genetic information?
A) Random nucleotide pairing
B) Protein-directed RNA copying
C) Complementary base pairing
D) Lipid-mediated strand separation
Correct Answer: Complementary base pairing
Rationale: Each parental strand serves as a template for synthesis of its complementary daughter
strand. In dna replication, recognizing this mechanism helps distinguish the underlying process from
superficially similar findings and connects molecular changes with tissue-level consequences. The
alternative choices describe different structures, pathways, or responses and therefore do not
account for the specific mechanism tested in this scenario.
12. Which molecule is produced directly by transcription of a protein-coding gene?
A) Polypeptide
2026/2027 | Cellular Biology & Cellular Injury Q&A |
Nursing
1. What structural feature gives the plasma membrane selective permeability?
A) A phospholipid bilayer with embedded proteins
B) A rigid cellulose wall
C) A freely permeable protein sheet
D) A nuclear envelope
Correct Answer: A phospholipid bilayer with embedded proteins
Rationale: Its hydrophobic core limits passage of charged solutes while transport proteins regulate
specific movement. In cell membrane, recognizing this mechanism helps distinguish the underlying
process from superficially similar findings and connects molecular changes with tissue-level
consequences. The alternative choices describe different structures, pathways, or responses and
therefore do not account for the specific mechanism tested in this scenario.
2. Which process moves a solute down its concentration gradient without ATP through a carrier?
A) Primary active transport
B) Facilitated diffusion
C) Endocytosis
D) Exocytosis
Correct Answer: Facilitated diffusion
Rationale: A carrier permits passive movement of a specific solute without directly consuming
cellular energy. In membrane transport, recognizing this mechanism helps distinguish the underlying
process from superficially similar findings and connects molecular changes with tissue-level
consequences. The alternative choices describe different structures, pathways, or responses and
therefore do not account for the specific mechanism tested in this scenario.
3. How does the sodium–potassium ATPase normally move ions per ATP hydrolyzed?
A) Two sodium ions out and three potassium ions in
B) Three sodium ions in and two potassium ions out
C) Three sodium ions out and two potassium ions in
D) Equal sodium and potassium ions outward
,Correct Answer: Three sodium ions out and two potassium ions in
Rationale: The electrogenic pump preserves gradients essential for resting membrane potential and
cell volume. In ion gradients, recognizing this mechanism helps distinguish the underlying process
from superficially similar findings and connects molecular changes with tissue-level consequences.
The alternative choices describe different structures, pathways, or responses and therefore do not
account for the specific mechanism tested in this scenario.
4. A red blood cell placed in a markedly hypotonic solution is expected to undergo what change?
A) Water efflux and shrinkage
B) No net water movement
C) Immediate protein synthesis
D) Water influx and swelling
Correct Answer: Water influx and swelling
Rationale: Water moves toward the compartment with higher effective solute concentration across
its membrane. In osmosis, recognizing this mechanism helps distinguish the underlying process
from superficially similar findings and connects molecular changes with tissue-level consequences.
The alternative choices describe different structures, pathways, or responses and therefore do not
account for the specific mechanism tested in this scenario.
5. Which organelle produces most ATP during aerobic respiration?
A) Mitochondrion
B) Lysosome
C) Golgi apparatus
D) Nucleolus
Correct Answer: Mitochondrion
Rationale: Oxidative phosphorylation across the inner mitochondrial membrane supplies most ATP
in oxygenated cells. In mitochondria, recognizing this mechanism helps distinguish the underlying
process from superficially similar findings and connects molecular changes with tissue-level
consequences. The alternative choices describe different structures, pathways, or responses and
therefore do not account for the specific mechanism tested in this scenario.
6. A cell synthesizing large quantities of secreted proteins would have abundant which structure?
A) Smooth endoplasmic reticulum only
B) Rough endoplasmic reticulum
C) Peroxisomes only
,D) Centrioles only
Correct Answer: Rough endoplasmic reticulum
Rationale: Ribosome-studded rough endoplasmic reticulum translates proteins destined for
secretion and membranes. In rough er, recognizing this mechanism helps distinguish the underlying
process from superficially similar findings and connects molecular changes with tissue-level
consequences. The alternative choices describe different structures, pathways, or responses and
therefore do not account for the specific mechanism tested in this scenario.
7. Following synthesis in rough endoplasmic reticulum, where are secretory proteins modified and
sorted?
A) Nucleus
B) Peroxisome
C) Golgi apparatus
D) Mitochondrial matrix
Correct Answer: Golgi apparatus
Rationale: The Golgi modifies and packages proteins for their appropriate intracellular or
extracellular destinations. In golgi, recognizing this mechanism helps distinguish the underlying
process from superficially similar findings and connects molecular changes with tissue-level
consequences. The alternative choices describe different structures, pathways, or responses and
therefore do not account for the specific mechanism tested in this scenario.
8. Loss of lysosomal membrane integrity most directly causes which consequence?
A) Increased nuclear DNA replication
B) Accelerated ATP synthesis
C) Enhanced ribosome assembly
D) Release of hydrolytic enzymes into cytosol
Correct Answer: Release of hydrolytic enzymes into cytosol
Rationale: Lysosomal hydrolases digest macromolecules and can contribute to cellular destruction
when released. In lysosomes, recognizing this mechanism helps distinguish the underlying process
from superficially similar findings and connects molecular changes with tissue-level consequences.
The alternative choices describe different structures, pathways, or responses and therefore do not
account for the specific mechanism tested in this scenario.
9. Which function is especially associated with peroxisomes?
A) Oxidation of very-long-chain fatty acids
B) Assembly of ribosomal RNA
, C) Packaging of secreted insulin
D) Spindle fiber formation
Correct Answer: Oxidation of very-long-chain fatty acids
Rationale: Peroxisomes contain oxidative enzymes and catalase that process selected lipids and
hydrogen peroxide. In peroxisomes, recognizing this mechanism helps distinguish the underlying
process from superficially similar findings and connects molecular changes with tissue-level
consequences. The alternative choices describe different structures, pathways, or responses and
therefore do not account for the specific mechanism tested in this scenario.
10. What cellular component is primarily responsible for mitotic spindle formation?
A) Collagen fibers
B) Microtubules
C) Plasma proteins
D) Glycogen granules
Correct Answer: Microtubules
Rationale: Tubulin-based microtubules organize chromosomes during mitosis and also support
intracellular transport. In cytoskeleton, recognizing this mechanism helps distinguish the underlying
process from superficially similar findings and connects molecular changes with tissue-level
consequences. The alternative choices describe different structures, pathways, or responses and
therefore do not account for the specific mechanism tested in this scenario.
11. During DNA replication, which principle preserves genetic information?
A) Random nucleotide pairing
B) Protein-directed RNA copying
C) Complementary base pairing
D) Lipid-mediated strand separation
Correct Answer: Complementary base pairing
Rationale: Each parental strand serves as a template for synthesis of its complementary daughter
strand. In dna replication, recognizing this mechanism helps distinguish the underlying process from
superficially similar findings and connects molecular changes with tissue-level consequences. The
alternative choices describe different structures, pathways, or responses and therefore do not
account for the specific mechanism tested in this scenario.
12. Which molecule is produced directly by transcription of a protein-coding gene?
A) Polypeptide
