): Advanced
Pathophysiology | Questions and
Verified Answers | 100% Correct |
Grade A - Wilkes
Question 1
A cell is exposed to a toxin that damages mitochondrial DNA. Which cellular
function will be most immediately impaired?
A) Protein synthesis
B) ATP production
C) Lipid synthesis
D) DNA replication
Correct Answer: B
Rationale: Mitochondria are the primary site of oxidative phosphorylation and ATP
production. Damage to mitochondrial DNA impairs the electron transport chain,
reducing ATP synthesis .
,Question 2
Which of the following are the three major components of eukaryotic cells?
A) Nucleus, ribosomes, and cell membrane
B) Nucleus, cytoplasm, and mitochondria
C) Nucleus, cytoplasm, and cell membrane
D) Cell membrane, mitochondria, and Golgi apparatus
Correct Answer: C
Rationale: The three major components of eukaryotic cells are the nucleus (control
center containing DNA), cytoplasm (contains water, electrolytes, proteins, and fats), and
cell membrane (semipermeable phospholipid bilayer with protein receptor sites) .
Question 3
Which organelle is responsible for creating ATP and is known as the "powerhouse
of the cell"?
A) Ribosomes
B) Golgi apparatus
C) Lysosomes
D) Mitochondria
Correct Answer: D
Rationale: Mitochondria are responsible for cellular respiration and ATP production
through oxidative phosphorylation. Ribosomes synthesize proteins, the Golgi apparatus
packages substances for excretion, and lysosomes break down substances for reuse .
Question 4
,During which phase of the cell cycle does DNA replication occur?
A) Prophase
B) G1 phase
C) S phase
D) Telophase
Correct Answer: C
Rationale: The S phase (synthesis phase) of interphase is when DNA replication occurs,
duplicating the genetic material in preparation for cell division. During G1, the cell
grows and performs normal functions; during G2, it prepares for mitosis .
Question 5
What is the function of lysosomes within the cell?
A) Protein synthesis
B) Energy production
C) Breakdown of substances to be used again
D) Packaging of excreted substances
Correct Answer: C
Rationale: Lysosomes contain hydrolytic enzymes that break down cellular waste,
damaged organelles, and foreign materials through phagocytosis and autophagy. They
recycle cellular components for reuse .
Question 6
Ribosomes are the site of:
A) ATP production
B) Protein synthesis
C) Lipid synthesis
D) DNA replication
, Correct Answer: B
Rationale: Ribosomes, composed of rRNA and protein, translate messenger RNA
(mRNA) sequences into polypeptide chains during protein synthesis. Free ribosomes
synthesize intracellular proteins, while rough ER-bound ribosomes synthesize proteins
for secretion .
Question 7
Which of the following best describes the cell membrane?
A) A rigid, impermeable barrier
B) A semipermeable phospholipid bilayer
C) A single layer of proteins
D) A carbohydrate-based structure
Correct Answer: B
Rationale: The cell membrane consists of a phospholipid bilayer with embedded
proteins. The hydrophobic tails face inward, while hydrophilic heads face the aqueous
environments. This structure allows selective permeability .
Question 8
What is the function of membrane receptors?
A) Protein synthesis
B) Energy production
C) Open and close channels allowing substances to pass through
D) DNA replication
Correct Answer: C
Rationale: Membrane receptors are protein structures that bind specific ligands
(hormones, neurotransmitters), triggering conformational changes that open or close
ion channels or activate intracellular signaling cascades .