TEST BANK FOR KARP’S CELL AND MOLECULAR
BIOLOGY 2025/2026 | 235+ VERIFIED QUESTIONS WITH
CORRECT ANSWERS & DETAILED RATIONALES |
COMPLETE STUDY GUIDE & EXAM PREP RESOURCE
QUESTION 1:
Which structure is responsible for the synthesis of ATP in eukaryotic cells?
A) Nucleus
B) Golgi apparatus
C) Mitochondria
D) Ribosomes
ANSWER: C - "Mitochondria."
Rationale: Mitochondria are known as the powerhouses of the cell and are responsible
for ATP synthesis through oxidative phosphorylation.
QUESTION 2:
What is the primary function of the rough endoplasmic reticulum?
A) Lipid synthesis
B) Protein synthesis
C) Carbohydrate metabolism
D) DNA replication
ANSWER: B - "Protein synthesis."
Rationale: The rough endoplasmic reticulum is studded with ribosomes, which are
sites of protein synthesis, particularly for proteins destined for secretion or for use in
membranes.
QUESTION 3:
Which of the following is true about prokaryotic cells?
A) They contain a nucleus.
B) They have membrane-bound organelles.
C) They are generally smaller than eukaryotic cells.
D) They replicate via mitosis.
ANSWER: C - "They are generally smaller than eukaryotic cells."
Rationale: Prokaryotic cells are typically smaller and simpler than eukaryotic cells,
lacking a nucleus and membrane-bound organelles.
,QUESTION 4:
What is the function of lysosomes in a cell?
A) Energy production
B) Protein synthesis
C) Digestion of macromolecules
D) DNA replication
ANSWER: C - "Digestion of macromolecules."
Rationale: Lysosomes contain hydrolytic enzymes that break down macromolecules,
old cell parts, and microorganisms.
QUESTION 5:
Which process involves the movement of water across a selectively permeable
membrane?
A) Osmosis
B) Diffusion
C) Active transport
D) Facilitated diffusion
ANSWER: A - "Osmosis."
Rationale: Osmosis is the movement of water molecules through a selectively
permeable membrane from an area of lower solute concentration to an area of higher
solute concentration.
QUESTION 6:
What is the role of ribosomes in the cell?
A) Energy production
B) Lipid synthesis
C) Protein synthesis
D) DNA replication
ANSWER: C - "Protein synthesis."
Rationale: Ribosomes are the cellular machinery responsible for translating mRNA into
proteins.
QUESTION 7:
Which component of the cytoskeleton is primarily involved in maintaining cell shape
and enabling cell movement?
,A) Microfilaments
B) Intermediate filaments
C) Microtubules
D) Centrioles
ANSWER: A - "Microfilaments."
Rationale: Microfilaments are involved in maintaining cell shape and are essential for
cellular movements, including muscle contraction and cell division.
QUESTION 8:
Which type of RNA carries amino acids to the ribosome during protein synthesis?
A) mRNA
B) rRNA
C) tRNA
D) snRNA
ANSWER: C - "tRNA."
Rationale: Transfer RNA (tRNA) transports specific amino acids to the ribosome, where
proteins are synthesized based on the sequence of mRNA.
QUESTION 9:
What is the function of the Golgi apparatus?
A) Protein synthesis
B) Modification and packaging of proteins
C) Energy production
D) DNA replication
ANSWER: B - "Modification and packaging of proteins."
Rationale: The Golgi apparatus modifies, sorts, and packages proteins and lipids for
secretion or delivery to other organelles.
QUESTION 10:
What is the primary function of the plasma membrane?
A) Energy production
B) Regulation of substance entry and exit
C) Protein synthesis
D) DNA replication
, ANSWER: B - "Regulation of substance entry and exit."
Rationale: The plasma membrane controls the movement of substances in and out of
the cell, maintaining homeostasis.
QUESTION 11:
Which of the following is a characteristic of eukaryotic cells?
A) Lack of a nucleus
B) Smaller size compared to prokaryotic cells
C) Presence of membrane-bound organelles
D) Reproduction by binary fission
ANSWER: C - "Presence of membrane-bound organelles."
Rationale: Eukaryotic cells have a defined nucleus and membrane-bound organelles,
distinguishing them from prokaryotic cells.
QUESTION 12:
What is the primary role of the nucleolus in the cell?
A) DNA replication
B) Ribosome production
C) Protein synthesis
D) Lipid metabolism
ANSWER: B - "Ribosome production."
Rationale: The nucleolus is responsible for synthesizing ribosomal RNA (rRNA) and
assembling ribosome subunits.
QUESTION 13:
What type of bond holds the two strands of DNA together?
A) Ionic bonds
B) Covalent bonds
C) Hydrogen bonds
D) Peptide bonds
ANSWER: C - "Hydrogen bonds."
Rationale: Hydrogen bonds form between the nitrogenous bases of the two DNA
strands, stabilizing the double helix structure.
QUESTION 14:
Which phase of the cell cycle involves DNA replication?
BIOLOGY 2025/2026 | 235+ VERIFIED QUESTIONS WITH
CORRECT ANSWERS & DETAILED RATIONALES |
COMPLETE STUDY GUIDE & EXAM PREP RESOURCE
QUESTION 1:
Which structure is responsible for the synthesis of ATP in eukaryotic cells?
A) Nucleus
B) Golgi apparatus
C) Mitochondria
D) Ribosomes
ANSWER: C - "Mitochondria."
Rationale: Mitochondria are known as the powerhouses of the cell and are responsible
for ATP synthesis through oxidative phosphorylation.
QUESTION 2:
What is the primary function of the rough endoplasmic reticulum?
A) Lipid synthesis
B) Protein synthesis
C) Carbohydrate metabolism
D) DNA replication
ANSWER: B - "Protein synthesis."
Rationale: The rough endoplasmic reticulum is studded with ribosomes, which are
sites of protein synthesis, particularly for proteins destined for secretion or for use in
membranes.
QUESTION 3:
Which of the following is true about prokaryotic cells?
A) They contain a nucleus.
B) They have membrane-bound organelles.
C) They are generally smaller than eukaryotic cells.
D) They replicate via mitosis.
ANSWER: C - "They are generally smaller than eukaryotic cells."
Rationale: Prokaryotic cells are typically smaller and simpler than eukaryotic cells,
lacking a nucleus and membrane-bound organelles.
,QUESTION 4:
What is the function of lysosomes in a cell?
A) Energy production
B) Protein synthesis
C) Digestion of macromolecules
D) DNA replication
ANSWER: C - "Digestion of macromolecules."
Rationale: Lysosomes contain hydrolytic enzymes that break down macromolecules,
old cell parts, and microorganisms.
QUESTION 5:
Which process involves the movement of water across a selectively permeable
membrane?
A) Osmosis
B) Diffusion
C) Active transport
D) Facilitated diffusion
ANSWER: A - "Osmosis."
Rationale: Osmosis is the movement of water molecules through a selectively
permeable membrane from an area of lower solute concentration to an area of higher
solute concentration.
QUESTION 6:
What is the role of ribosomes in the cell?
A) Energy production
B) Lipid synthesis
C) Protein synthesis
D) DNA replication
ANSWER: C - "Protein synthesis."
Rationale: Ribosomes are the cellular machinery responsible for translating mRNA into
proteins.
QUESTION 7:
Which component of the cytoskeleton is primarily involved in maintaining cell shape
and enabling cell movement?
,A) Microfilaments
B) Intermediate filaments
C) Microtubules
D) Centrioles
ANSWER: A - "Microfilaments."
Rationale: Microfilaments are involved in maintaining cell shape and are essential for
cellular movements, including muscle contraction and cell division.
QUESTION 8:
Which type of RNA carries amino acids to the ribosome during protein synthesis?
A) mRNA
B) rRNA
C) tRNA
D) snRNA
ANSWER: C - "tRNA."
Rationale: Transfer RNA (tRNA) transports specific amino acids to the ribosome, where
proteins are synthesized based on the sequence of mRNA.
QUESTION 9:
What is the function of the Golgi apparatus?
A) Protein synthesis
B) Modification and packaging of proteins
C) Energy production
D) DNA replication
ANSWER: B - "Modification and packaging of proteins."
Rationale: The Golgi apparatus modifies, sorts, and packages proteins and lipids for
secretion or delivery to other organelles.
QUESTION 10:
What is the primary function of the plasma membrane?
A) Energy production
B) Regulation of substance entry and exit
C) Protein synthesis
D) DNA replication
, ANSWER: B - "Regulation of substance entry and exit."
Rationale: The plasma membrane controls the movement of substances in and out of
the cell, maintaining homeostasis.
QUESTION 11:
Which of the following is a characteristic of eukaryotic cells?
A) Lack of a nucleus
B) Smaller size compared to prokaryotic cells
C) Presence of membrane-bound organelles
D) Reproduction by binary fission
ANSWER: C - "Presence of membrane-bound organelles."
Rationale: Eukaryotic cells have a defined nucleus and membrane-bound organelles,
distinguishing them from prokaryotic cells.
QUESTION 12:
What is the primary role of the nucleolus in the cell?
A) DNA replication
B) Ribosome production
C) Protein synthesis
D) Lipid metabolism
ANSWER: B - "Ribosome production."
Rationale: The nucleolus is responsible for synthesizing ribosomal RNA (rRNA) and
assembling ribosome subunits.
QUESTION 13:
What type of bond holds the two strands of DNA together?
A) Ionic bonds
B) Covalent bonds
C) Hydrogen bonds
D) Peptide bonds
ANSWER: C - "Hydrogen bonds."
Rationale: Hydrogen bonds form between the nitrogenous bases of the two DNA
strands, stabilizing the double helix structure.
QUESTION 14:
Which phase of the cell cycle involves DNA replication?
