PCB3023C Cell Biology Exam 1 Practice 2026 |FGCU
1. Where is the specific site of ribosomal RNA (rRNA) synthesis in a eukaryotic
cell?
A. Cytoplasm
B. Rough Endoplasmic Reticulum
C. Golgi Apparatus
D. Nucleolus
Answer: D
Rationale: The nucleolus is a non-membrane bound structure within the nucleus
responsible for the transcription of rRNA and the assembly of ribosome subunits.
2. Which molecule is the primary structural component of the cell membrane’s
lipid bilayer?
A. Triglycerides
B. Glycoproteins
C. Cholesterol
D. Phospholipids
Answer: D
Rationale: Phospholipids are amphipathic molecules with hydrophilic heads and
hydrophobic tails that spontaneously form the bilayer structure of the cell membrane.
,3. Which organelle is primarily responsible for lipid synthesis and the
detoxification of drugs?
A. Ribosomes
B. Lysosomes
C. Nucleus
D. Smooth Endoplasmic Reticulum
Answer: D
Rationale: The Smooth ER lacks ribosomes and is involved in various metabolic processes,
including lipid synthesis, carbohydrate metabolism, and detoxification.
4. Where does the Electron Transport Chain take place in eukaryotes?
A. Cytosol
B. Inner Mitochondrial Membrane
C. Outer Mitochondrial Membrane
D. Mitochondrial Matrix
Answer: B
Rationale: The Electron Transport Chain is located in the inner mitochondrial membrane
(cristae) where it creates a proton gradient for ATP production.
5. What is the primary function of lysosomes?
A. Protein synthesis
B. Intracellular digestion via hydrolytic enzymes
C. Storage of genetic information
D. Energy production
Answer: B
Rationale: Lysosomes contain acid hydrolases that break down macromolecules, old
organelles, and foreign substances via phagocytosis or autophagy.
, 6. The ‘shipping and receiving’ center of the cell, responsible for modifying
proteins, is the:
A. Nucleus
B. Rough ER
C. Peroxisome
D. Golgi Apparatus
Answer: D
Rationale: The Golgi apparatus receives proteins from the ER, modifies them (e.g.,
glycosylation), and sorts them for their final destination.
7. Which process involves the movement of water across a semi-permeable
membrane?
A. Simple Diffusion
B. Active Transport
C. Endocytosis
D. Osmosis
Answer: D
Rationale: Osmosis is the specific term for the diffusion of water from an area of low solute
concentration to high solute concentration.
8. How many Sodium (Na+) and Potassium (K+) ions are moved by the Na+/K+
ATPase pump per ATP cycle?
A. 2 Na+ out, 3 K+ in
B. 3 Na+ in, 2 K+ out
C. 2 Na+ in, 3 K+ out
D. 3 Na+ out, 2 K+ in
Answer: D
Rationale: The Na+/K+ pump moves three sodium ions out of the cell and two potassium
ions into the cell, using energy from one ATP molecule.
1. Where is the specific site of ribosomal RNA (rRNA) synthesis in a eukaryotic
cell?
A. Cytoplasm
B. Rough Endoplasmic Reticulum
C. Golgi Apparatus
D. Nucleolus
Answer: D
Rationale: The nucleolus is a non-membrane bound structure within the nucleus
responsible for the transcription of rRNA and the assembly of ribosome subunits.
2. Which molecule is the primary structural component of the cell membrane’s
lipid bilayer?
A. Triglycerides
B. Glycoproteins
C. Cholesterol
D. Phospholipids
Answer: D
Rationale: Phospholipids are amphipathic molecules with hydrophilic heads and
hydrophobic tails that spontaneously form the bilayer structure of the cell membrane.
,3. Which organelle is primarily responsible for lipid synthesis and the
detoxification of drugs?
A. Ribosomes
B. Lysosomes
C. Nucleus
D. Smooth Endoplasmic Reticulum
Answer: D
Rationale: The Smooth ER lacks ribosomes and is involved in various metabolic processes,
including lipid synthesis, carbohydrate metabolism, and detoxification.
4. Where does the Electron Transport Chain take place in eukaryotes?
A. Cytosol
B. Inner Mitochondrial Membrane
C. Outer Mitochondrial Membrane
D. Mitochondrial Matrix
Answer: B
Rationale: The Electron Transport Chain is located in the inner mitochondrial membrane
(cristae) where it creates a proton gradient for ATP production.
5. What is the primary function of lysosomes?
A. Protein synthesis
B. Intracellular digestion via hydrolytic enzymes
C. Storage of genetic information
D. Energy production
Answer: B
Rationale: Lysosomes contain acid hydrolases that break down macromolecules, old
organelles, and foreign substances via phagocytosis or autophagy.
, 6. The ‘shipping and receiving’ center of the cell, responsible for modifying
proteins, is the:
A. Nucleus
B. Rough ER
C. Peroxisome
D. Golgi Apparatus
Answer: D
Rationale: The Golgi apparatus receives proteins from the ER, modifies them (e.g.,
glycosylation), and sorts them for their final destination.
7. Which process involves the movement of water across a semi-permeable
membrane?
A. Simple Diffusion
B. Active Transport
C. Endocytosis
D. Osmosis
Answer: D
Rationale: Osmosis is the specific term for the diffusion of water from an area of low solute
concentration to high solute concentration.
8. How many Sodium (Na+) and Potassium (K+) ions are moved by the Na+/K+
ATPase pump per ATP cycle?
A. 2 Na+ out, 3 K+ in
B. 3 Na+ in, 2 K+ out
C. 2 Na+ in, 3 K+ out
D. 3 Na+ out, 2 K+ in
Answer: D
Rationale: The Na+/K+ pump moves three sodium ions out of the cell and two potassium
ions into the cell, using energy from one ATP molecule.
