1|Page
UWL BIO 315 Exam 2026-2027 BANK QUESTIONS WITH
DETAILED VERIFIED ANSWERS EXAM QUESTIONS WILL
COME FROM HERE (100% Latest Already Graded A+
Question 1
The endosymbiotic theory proposes that mitochondria and chloroplasts
originated from:
A) Viruses that infected ancient eukaryotic cells
B) Free-living prokaryotes that were engulfed by ancestral eukaryotic
cells
C) Nuclei that escaped from adjacent cells
D) Vesicles formed from the plasma membrane
Answer: B
Explanation: The endosymbiotic theory, supported by the presence of
circular DNA, double membranes, and ribosomes similar to bacteria in
mitochondria and chloroplasts, states that these organelles evolved
from free-living bacteria that entered into a symbiotic relationship with
a host cell.
Question 2
In a typical animal cell, the organelle primarily responsible for the
modification, sorting, and packaging of proteins for secretion is the:
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A) Rough endoplasmic reticulum
B) Smooth endoplasmic reticulum
C) Golgi apparatus
D) Lysosome
Answer: C
Explanation: The Golgi apparatus receives proteins from the ER,
modifies them (e.g., glycosylation), and packages them into vesicles for
transport to their final destinations, including the plasma membrane for
secretion.
Question 3
Which of the following is NOT a function of the smooth endoplasmic
reticulum?
A) Lipid synthesis
B) Detoxification of drugs
C) Calcium ion storage
D) Protein synthesis
Answer: D
Explanation: Protein synthesis is the primary function of the rough ER,
which is studded with ribosomes. The smooth ER is involved in lipid
metabolism, detoxification, and calcium storage.
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Question 4
The fluid mosaic model describes the plasma membrane as:
A) A static, rigid layer of phospholipids and proteins
B) A bilayer of phospholipids in which proteins are embedded and can
move laterally
C) A monolayer of glycolipids with peripheral proteins
D) A trilaminar structure with a central protein layer
Answer: B
Explanation: The fluid mosaic model, proposed by Singer and Nicolson,
depicts the membrane as a fluid phospholipid bilayer with embedded
proteins that can move laterally, allowing for dynamic function.
Question 5
Cholesterol in animal cell membranes functions to:
A) Increase membrane permeability to all solutes
B) Decrease membrane fluidity at high temperatures and prevent
crystallization at low temperatures
C) Act as a primary energy source
D) Synthesize phospholipids
Answer: B
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Explanation: Cholesterol inserts between phospholipid tails, reducing
fluidity at higher temperatures by restricting movement, and preventing
packing at lower temperatures, thus maintaining membrane stability.
Question 6
Osmosis is the movement of:
A) Solutes across a selectively permeable membrane from high to low
concentration
B) Water across a selectively permeable membrane from high water
potential to low water potential
C) Water across a membrane from low solute concentration to high
solute concentration using ATP
D) Solutes against their concentration gradient using protein pumps
Answer: B
Explanation: Osmosis is the passive movement of water across a
selectively permeable membrane driven by differences in water
potential (or solute concentration), moving from areas of higher water
potential to lower.
Question 7
A cell placed in a hypertonic solution will:
A) Swell and possibly burst
B) Remain unchanged
UWL BIO 315 Exam 2026-2027 BANK QUESTIONS WITH
DETAILED VERIFIED ANSWERS EXAM QUESTIONS WILL
COME FROM HERE (100% Latest Already Graded A+
Question 1
The endosymbiotic theory proposes that mitochondria and chloroplasts
originated from:
A) Viruses that infected ancient eukaryotic cells
B) Free-living prokaryotes that were engulfed by ancestral eukaryotic
cells
C) Nuclei that escaped from adjacent cells
D) Vesicles formed from the plasma membrane
Answer: B
Explanation: The endosymbiotic theory, supported by the presence of
circular DNA, double membranes, and ribosomes similar to bacteria in
mitochondria and chloroplasts, states that these organelles evolved
from free-living bacteria that entered into a symbiotic relationship with
a host cell.
Question 2
In a typical animal cell, the organelle primarily responsible for the
modification, sorting, and packaging of proteins for secretion is the:
,2|Page
A) Rough endoplasmic reticulum
B) Smooth endoplasmic reticulum
C) Golgi apparatus
D) Lysosome
Answer: C
Explanation: The Golgi apparatus receives proteins from the ER,
modifies them (e.g., glycosylation), and packages them into vesicles for
transport to their final destinations, including the plasma membrane for
secretion.
Question 3
Which of the following is NOT a function of the smooth endoplasmic
reticulum?
A) Lipid synthesis
B) Detoxification of drugs
C) Calcium ion storage
D) Protein synthesis
Answer: D
Explanation: Protein synthesis is the primary function of the rough ER,
which is studded with ribosomes. The smooth ER is involved in lipid
metabolism, detoxification, and calcium storage.
,3|Page
Question 4
The fluid mosaic model describes the plasma membrane as:
A) A static, rigid layer of phospholipids and proteins
B) A bilayer of phospholipids in which proteins are embedded and can
move laterally
C) A monolayer of glycolipids with peripheral proteins
D) A trilaminar structure with a central protein layer
Answer: B
Explanation: The fluid mosaic model, proposed by Singer and Nicolson,
depicts the membrane as a fluid phospholipid bilayer with embedded
proteins that can move laterally, allowing for dynamic function.
Question 5
Cholesterol in animal cell membranes functions to:
A) Increase membrane permeability to all solutes
B) Decrease membrane fluidity at high temperatures and prevent
crystallization at low temperatures
C) Act as a primary energy source
D) Synthesize phospholipids
Answer: B
, 4|Page
Explanation: Cholesterol inserts between phospholipid tails, reducing
fluidity at higher temperatures by restricting movement, and preventing
packing at lower temperatures, thus maintaining membrane stability.
Question 6
Osmosis is the movement of:
A) Solutes across a selectively permeable membrane from high to low
concentration
B) Water across a selectively permeable membrane from high water
potential to low water potential
C) Water across a membrane from low solute concentration to high
solute concentration using ATP
D) Solutes against their concentration gradient using protein pumps
Answer: B
Explanation: Osmosis is the passive movement of water across a
selectively permeable membrane driven by differences in water
potential (or solute concentration), moving from areas of higher water
potential to lower.
Question 7
A cell placed in a hypertonic solution will:
A) Swell and possibly burst
B) Remain unchanged
