PCB3023C Cell Biology Final Exam Prep 2026 – FGCU
1. Which molecule is primarily responsible for maintaining the fluidity of the
plasma membrane in animal cells at various temperatures?
A. Phospholipids
B. Cholesterol
C. Glycoproteins
D. Peripheral proteins
Answer: B
Rationale: Cholesterol acts as a fluidity buffer, preventing the membrane from becoming
too fluid at high temperatures and too rigid at low temperatures.
2. In which part of the eukaryotic cell does the Citric Acid (Krebs) Cycle take
place?
A. Cytosol
B. Mitochondrial matrix
C. Inner mitochondrial membrane
D. Intermembrane space
Answer: B
Rationale: While glycolysis occurs in the cytosol, the Krebs Cycle occurs within the matrix
of the mitochondria.
,3. Which cytoskeletal filament is composed of actin subunits and is involved in
muscle contraction and cell crawling?
A. Microtubules
B. Microfilaments
C. Intermediate filaments
D. Myosin filaments
Answer: B
Rationale: Microfilaments are made of actin and are essential for movements like
cytokinesis and cell crawling.
4. What is the net gain of ATP molecules produced during glycolysis from a
single molecule of glucose?
A. 4 ATP
B. 2 ATP
C. 32 ATP
D. 36 ATP
Answer: B
Rationale: Glycolysis produces 4 ATP but consumes 2 ATP, resulting in a net gain of 2 ATP.
5. How do enzymes increase the rate of a chemical reaction?
A. By lowering the activation energy barrier
B. By increasing the free energy of the products
C. By increasing the temperature of the reaction
D. By changing the equilibrium constant
Answer: A
Rationale: Enzymes act as catalysts by lowering the activation energy required for a
reaction to proceed.
, 6. Which organelle is responsible for the synthesis of lipids and the
detoxification of drugs?
A. Rough Endoplasmic Reticulum
B. Smooth Endoplasmic Reticulum
C. Golgi Apparatus
D. Lysosome
Answer: B
Rationale: The Smooth ER is specialized for lipid synthesis, calcium storage, and
detoxification, whereas the Rough ER is for protein synthesis.
7. During which phase of the cell cycle does DNA replication occur?
A. G1 phase
B. M phase
C. G2 phase
D. S phase
Answer: D
Rationale: The S phase (Synthesis phase) is dedicated to the replication of the cell’s genetic
material.
8. Which protein complex serves as the ‘sorting center’ of the cell, modifying
and packaging proteins for secretion?
A. Nucleus
B. Ribosome
C. Golgi apparatus
D. Peroxisome
Answer: C
Rationale: The Golgi apparatus receives proteins from the ER and modifies, sorts, and
packages them into vesicles.
1. Which molecule is primarily responsible for maintaining the fluidity of the
plasma membrane in animal cells at various temperatures?
A. Phospholipids
B. Cholesterol
C. Glycoproteins
D. Peripheral proteins
Answer: B
Rationale: Cholesterol acts as a fluidity buffer, preventing the membrane from becoming
too fluid at high temperatures and too rigid at low temperatures.
2. In which part of the eukaryotic cell does the Citric Acid (Krebs) Cycle take
place?
A. Cytosol
B. Mitochondrial matrix
C. Inner mitochondrial membrane
D. Intermembrane space
Answer: B
Rationale: While glycolysis occurs in the cytosol, the Krebs Cycle occurs within the matrix
of the mitochondria.
,3. Which cytoskeletal filament is composed of actin subunits and is involved in
muscle contraction and cell crawling?
A. Microtubules
B. Microfilaments
C. Intermediate filaments
D. Myosin filaments
Answer: B
Rationale: Microfilaments are made of actin and are essential for movements like
cytokinesis and cell crawling.
4. What is the net gain of ATP molecules produced during glycolysis from a
single molecule of glucose?
A. 4 ATP
B. 2 ATP
C. 32 ATP
D. 36 ATP
Answer: B
Rationale: Glycolysis produces 4 ATP but consumes 2 ATP, resulting in a net gain of 2 ATP.
5. How do enzymes increase the rate of a chemical reaction?
A. By lowering the activation energy barrier
B. By increasing the free energy of the products
C. By increasing the temperature of the reaction
D. By changing the equilibrium constant
Answer: A
Rationale: Enzymes act as catalysts by lowering the activation energy required for a
reaction to proceed.
, 6. Which organelle is responsible for the synthesis of lipids and the
detoxification of drugs?
A. Rough Endoplasmic Reticulum
B. Smooth Endoplasmic Reticulum
C. Golgi Apparatus
D. Lysosome
Answer: B
Rationale: The Smooth ER is specialized for lipid synthesis, calcium storage, and
detoxification, whereas the Rough ER is for protein synthesis.
7. During which phase of the cell cycle does DNA replication occur?
A. G1 phase
B. M phase
C. G2 phase
D. S phase
Answer: D
Rationale: The S phase (Synthesis phase) is dedicated to the replication of the cell’s genetic
material.
8. Which protein complex serves as the ‘sorting center’ of the cell, modifying
and packaging proteins for secretion?
A. Nucleus
B. Ribosome
C. Golgi apparatus
D. Peroxisome
Answer: C
Rationale: The Golgi apparatus receives proteins from the ER and modifies, sorts, and
packages them into vesicles.
