,1: Cell Physiology
Practice Test Bank – Cell Physiology
Question 1
Which organelle is primarily responsible for ATP production?
A. Nucleus
B. Mitochondria
C. Endoplasmic reticulum
D. Lysosome
Answer: B
Rationale: Mitochondria are the “powerhouses” of the cell, producing ATP via oxidative
phosphorylation.
Question 2
Which transport process requires energy input?
A. Simple diffusion
B. Facilitated diffusion
C. Osmosis
D. Active transport
Answer: D
Rationale: Active transport moves molecules against their gradient using ATP or ion gradients.
Question 3
Which ion is most critical for establishing resting membrane potential?
,A. Na⁺
B. K⁺
C. Ca²⁺
D. Cl⁻
Answer: B
Rationale: Potassium permeability dominates resting potential; K⁺ leak channels set the negative
interior.
Question 4
Which type of cell junction prevents paracellular movement of solutes?
A. Gap junctions
B. Tight junctions
C. Desmosomes
D. Hemidesmosomes
Answer: B
Rationale: Tight junctions seal epithelial cells together, preventing solute leakage between cells.
Question 5
Which signaling mechanism involves hormones traveling through the bloodstream?
A. Autocrine
B. Paracrine
C. Endocrine
D. Synaptic
, Answer: C
Rationale: Endocrine signaling uses hormones released into circulation to reach distant targets.
Question 6
Which phase of the cell cycle involves DNA replication?
A. G1
B. S
C. G2
D. M
Answer: B
Rationale: The S phase is where DNA synthesis occurs, preparing for cell division.
Question 7
Which enzyme is responsible for maintaining telomere length?
A. DNA polymerase
B. Telomerase
C. RNA polymerase
D. Ligase
Answer: B
Rationale: Telomerase adds repetitive sequences to chromosome ends, preventing shortening during
replication.
Question 8
Which type of feedback loop maintains homeostasis?
Practice Test Bank – Cell Physiology
Question 1
Which organelle is primarily responsible for ATP production?
A. Nucleus
B. Mitochondria
C. Endoplasmic reticulum
D. Lysosome
Answer: B
Rationale: Mitochondria are the “powerhouses” of the cell, producing ATP via oxidative
phosphorylation.
Question 2
Which transport process requires energy input?
A. Simple diffusion
B. Facilitated diffusion
C. Osmosis
D. Active transport
Answer: D
Rationale: Active transport moves molecules against their gradient using ATP or ion gradients.
Question 3
Which ion is most critical for establishing resting membrane potential?
,A. Na⁺
B. K⁺
C. Ca²⁺
D. Cl⁻
Answer: B
Rationale: Potassium permeability dominates resting potential; K⁺ leak channels set the negative
interior.
Question 4
Which type of cell junction prevents paracellular movement of solutes?
A. Gap junctions
B. Tight junctions
C. Desmosomes
D. Hemidesmosomes
Answer: B
Rationale: Tight junctions seal epithelial cells together, preventing solute leakage between cells.
Question 5
Which signaling mechanism involves hormones traveling through the bloodstream?
A. Autocrine
B. Paracrine
C. Endocrine
D. Synaptic
, Answer: C
Rationale: Endocrine signaling uses hormones released into circulation to reach distant targets.
Question 6
Which phase of the cell cycle involves DNA replication?
A. G1
B. S
C. G2
D. M
Answer: B
Rationale: The S phase is where DNA synthesis occurs, preparing for cell division.
Question 7
Which enzyme is responsible for maintaining telomere length?
A. DNA polymerase
B. Telomerase
C. RNA polymerase
D. Ligase
Answer: B
Rationale: Telomerase adds repetitive sequences to chromosome ends, preventing shortening during
replication.
Question 8
Which type of feedback loop maintains homeostasis?
