MULTIPLE-CHOICE QUESTIONS WITH ANSWERS AND
RATIONALES
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EXAM 1: Cellular Biology, Injury, Adaptation, Fluid Balance, and Genetics
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**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
**Answer: B) ATP production**
*Rationale: Mitochondria are the primary site of oxidative phosphorylation and
ATP production. Damage to mitochondrial DNA impairs the electron transport
,chain, reducing ATP synthesis. Cells with high energy demands (neurons, cardiac
muscle) are most vulnerable .*
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**Question 2**
Which type of cellular adaptation involves an increase in the number of cells in a
tissue?
A) Hypertrophy
B) Hyperplasia
C) Atrophy
D) Metaplasia
**Answer: B) Hyperplasia**
*Rationale: Hyperplasia is an increase in cell number due to increased mitotic
division. It occurs in tissues capable of mitosis (e.g., endometrium during the
menstrual cycle, liver regeneration). Hypertrophy is an increase in cell size,
atrophy is a decrease in cell size, and metaplasia is replacement of one cell type
with another .*
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**Question 3**
,Which statement best describes the cellular function of metabolic absorption?
A) Cells can produce proteins.
B) Cells can secrete digestive enzymes.
C) Cells can take in and use nutrients.
D) Cells can synthesize fats.
**Answer: C) Cells can take in and use nutrients.**
*Rationale: Metabolic absorption is the cellular function by which cells take in and
utilize nutrients for energy and growth. This is a fundamental function of all cells,
particularly epithelial cells lining the intestine .*
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**Question 4**
Most of a cell's genetic information, including RNA and DNA, is contained in which
structure?
A) Mitochondria
B) Ribosome
C) Nucleolus
D) Lysosome
, **Answer: C) Nucleolus**
*Rationale: The nucleolus is the site of rRNA synthesis and contains most of the
cell's genetic information. It is located within the nucleus and is essential for
protein synthesis .*
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**Question 5**
Which component of the cell produces hydrogen peroxide (H₂O₂) by using oxygen
to remove hydrogen atoms from specific substrates?
A) Lysosomes
B) Peroxisomes
C) Ribosomes
D) Oxyhydrosomes
**Answer: B) Peroxisomes**
*Rationale: Peroxisomes contain oxidative enzymes that produce hydrogen
peroxide as a byproduct of removing hydrogen atoms from substrates. They are
important for detoxification reactions .*
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