BIOL180 Lesson 2 Quiz Cell Structure
and Function Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
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1. Which statement best describes the cell theory?
A. All cells contain a nucleus.
B. All organisms are composed only of tissues.
C. Cells arise spontaneously from nonliving material.
D. All living organisms are composed of one or more cells.
Answer: D. All living organisms are composed of one or more cells.
Rationale: Cell theory states that all living organisms are made of one
or more cells, the cell is the basic unit of life, and new cells arise from
preexisting cells. Not every cell has a nucleus because prokaryotic cells
lack membrane-bound nuclei.
2. Which structure is present in both prokaryotic and eukaryotic
cells?
A. Plasma membrane
B. Nucleus
C. Golgi apparatus
D. Mitochondrion
Answer: A. Plasma membrane
,Rationale: Both prokaryotic and eukaryotic cells have plasma
membranes that regulate movement of substances into and out of the
cell. Eukaryotes additionally contain membrane-bound organelles
such as nuclei, mitochondria, and Golgi apparatuses, whereas
prokaryotes do not.
3. What is the primary function of the plasma membrane?
A. Produce ribosomes
B. Store genetic information
C. Regulate movement of substances into and out of the cell
D. Generate most cellular ATP
Answer: C. Regulate movement of substances into and out of the cell
Rationale: The plasma membrane forms a selectively permeable
boundary around the cell. It controls the movement of ions, nutrients,
waste products, and other molecules while also participating in cell
signaling and recognition.
4. Which component makes up the basic structural framework of a
biological membrane?
A. DNA
B. Phospholipid bilayer
C. Cellulose layer
D. Protein capsule
Answer: B. Phospholipid bilayer
Rationale: The plasma membrane is primarily organized as a
phospholipid bilayer. Phospholipids have hydrophilic heads that
interact with water and hydrophobic tails that avoid water, creating a
stable membrane structure.
5. Which part of a phospholipid is hydrophilic?
,A. Fatty acid tails
B. Hydrocarbon chains
C. Glycerol-free region
D. Phosphate-containing head
Answer: D. Phosphate-containing head
Rationale: The phosphate-containing head of a phospholipid is polar
and hydrophilic, meaning it interacts readily with water. The fatty acid
tails are nonpolar and hydrophobic and therefore orient toward the
interior of the bilayer.
6. Which component of the membrane contributes significantly to its
fluidity?
A. Cholesterol
B. DNA
C. Cellulose
D. RNA
Answer: A. Cholesterol
Rationale: Cholesterol is embedded among phospholipids and helps
regulate membrane fluidity. It can prevent phospholipids from packing
too tightly at lower temperatures while limiting excessive movement at
higher temperatures.
7. Which statement correctly describes integral membrane proteins?
A. They are found exclusively outside cells.
B. They are permanently attached to DNA.
C. They are embedded within the membrane.
D. They are composed entirely of carbohydrates.
Answer: C. They are embedded within the membrane.
, Rationale: Integral membrane proteins are embedded in the lipid
bilayer, and many span the entire membrane. They perform functions
including transport, signaling, enzymatic activity, and cell recognition.
8. Which structure contains the genetic material in a typical
eukaryotic cell?
A. Lysosome
B. Nucleus
C. Ribosome
D. Golgi apparatus
Answer: B. Nucleus
Rationale: The nucleus is a membrane-bound organelle that houses
most of the genetic material in eukaryotic cells. DNA within the
nucleus contains instructions used to regulate cellular activities and
protein production.
9. What is the primary function of ribosomes?
A. Digest cellular waste
B. Produce ATP
C. Modify lipids
D. Synthesize proteins
Answer: D. Synthesize proteins
Rationale: Ribosomes translate information carried by messenger RNA
into polypeptide chains. Ribosomes may be free in the cytoplasm or
attached to rough endoplasmic reticulum, depending on the
destination of the proteins being produced.
10. Which organelle is primarily responsible for modifying,
sorting, and packaging proteins?
and Function Questions And Correct
Answers (Verified Answers) Plus
Rationales 2026 Q&A | Instant
Download Pdf
1. Which statement best describes the cell theory?
A. All cells contain a nucleus.
B. All organisms are composed only of tissues.
C. Cells arise spontaneously from nonliving material.
D. All living organisms are composed of one or more cells.
Answer: D. All living organisms are composed of one or more cells.
Rationale: Cell theory states that all living organisms are made of one
or more cells, the cell is the basic unit of life, and new cells arise from
preexisting cells. Not every cell has a nucleus because prokaryotic cells
lack membrane-bound nuclei.
2. Which structure is present in both prokaryotic and eukaryotic
cells?
A. Plasma membrane
B. Nucleus
C. Golgi apparatus
D. Mitochondrion
Answer: A. Plasma membrane
,Rationale: Both prokaryotic and eukaryotic cells have plasma
membranes that regulate movement of substances into and out of the
cell. Eukaryotes additionally contain membrane-bound organelles
such as nuclei, mitochondria, and Golgi apparatuses, whereas
prokaryotes do not.
3. What is the primary function of the plasma membrane?
A. Produce ribosomes
B. Store genetic information
C. Regulate movement of substances into and out of the cell
D. Generate most cellular ATP
Answer: C. Regulate movement of substances into and out of the cell
Rationale: The plasma membrane forms a selectively permeable
boundary around the cell. It controls the movement of ions, nutrients,
waste products, and other molecules while also participating in cell
signaling and recognition.
4. Which component makes up the basic structural framework of a
biological membrane?
A. DNA
B. Phospholipid bilayer
C. Cellulose layer
D. Protein capsule
Answer: B. Phospholipid bilayer
Rationale: The plasma membrane is primarily organized as a
phospholipid bilayer. Phospholipids have hydrophilic heads that
interact with water and hydrophobic tails that avoid water, creating a
stable membrane structure.
5. Which part of a phospholipid is hydrophilic?
,A. Fatty acid tails
B. Hydrocarbon chains
C. Glycerol-free region
D. Phosphate-containing head
Answer: D. Phosphate-containing head
Rationale: The phosphate-containing head of a phospholipid is polar
and hydrophilic, meaning it interacts readily with water. The fatty acid
tails are nonpolar and hydrophobic and therefore orient toward the
interior of the bilayer.
6. Which component of the membrane contributes significantly to its
fluidity?
A. Cholesterol
B. DNA
C. Cellulose
D. RNA
Answer: A. Cholesterol
Rationale: Cholesterol is embedded among phospholipids and helps
regulate membrane fluidity. It can prevent phospholipids from packing
too tightly at lower temperatures while limiting excessive movement at
higher temperatures.
7. Which statement correctly describes integral membrane proteins?
A. They are found exclusively outside cells.
B. They are permanently attached to DNA.
C. They are embedded within the membrane.
D. They are composed entirely of carbohydrates.
Answer: C. They are embedded within the membrane.
, Rationale: Integral membrane proteins are embedded in the lipid
bilayer, and many span the entire membrane. They perform functions
including transport, signaling, enzymatic activity, and cell recognition.
8. Which structure contains the genetic material in a typical
eukaryotic cell?
A. Lysosome
B. Nucleus
C. Ribosome
D. Golgi apparatus
Answer: B. Nucleus
Rationale: The nucleus is a membrane-bound organelle that houses
most of the genetic material in eukaryotic cells. DNA within the
nucleus contains instructions used to regulate cellular activities and
protein production.
9. What is the primary function of ribosomes?
A. Digest cellular waste
B. Produce ATP
C. Modify lipids
D. Synthesize proteins
Answer: D. Synthesize proteins
Rationale: Ribosomes translate information carried by messenger RNA
into polypeptide chains. Ribosomes may be free in the cytoplasm or
attached to rough endoplasmic reticulum, depending on the
destination of the proteins being produced.
10. Which organelle is primarily responsible for modifying,
sorting, and packaging proteins?
