PCB3023 Exam 1: Molecular Cell Biology 2026 |UCF
1. Which organelle is responsible for the synthesis of lipids and the
detoxification of drugs?
A. Rough Endoplasmic Reticulum
B. Lysosome
C. Golgi Apparatus
D. Smooth Endoplasmic Reticulum
Answer: D
Rationale: The smooth ER is involved in lipid synthesis, carbohydrate metabolism, and
detoxification, unlike the rough ER which is studded with ribosomes for protein synthesis.
2. The limit of resolution of a standard light microscope is approximately:
A. 20 nanometers
B. 2.0 micrometers
C. 0.2 micrometers
D. 200 micrometers
Answer: C
Rationale: The resolution limit of light microscopy is roughly half the wavelength of visible
light, which is about 200 nm or 0.2 micrometers.
,3. Which of the following model organisms is commonly used to study the
genetics of development in a multicellular animal?
A. Escherichia coli
B. Drosophila melanogaster
C. Saccharomyces cerevisiae
D. Arabidopsis thaliana
Answer: B
Rationale: Drosophila melanogaster (the fruit fly) is a classic model for developmental
biology and genetics.
4. What type of bond is formed by the equal sharing of electrons between two
atoms?
A. Ionic bond
B. Nonpolar covalent bond
C. Hydrogen bond
D. Polar covalent bond
Answer: B
Rationale: Nonpolar covalent bonds occur when atoms share electrons equally, typically
between atoms of similar electronegativity.
5. Water molecules are polar because:
A. Oxygen and hydrogen have the same electronegativity
B. Hydrogen is more electronegative than oxygen
C. They contain ionic bonds
D. Oxygen is more electronegative than hydrogen
Answer: D
Rationale: The high electronegativity of oxygen causes an unequal distribution of charge,
making the molecule polar.
, 6. Which macromolecule is primarily responsible for the storage of genetic
information?
A. Proteins
B. Nucleic Acids
C. Carbohydrates
D. Lipids
Answer: B
Rationale: Nucleic acids (DNA and RNA) are the molecules that store and transmit genetic
information.
7. The primary structure of a protein refers to:
A. Alpha helices and beta sheets
B. The linear sequence of amino acids
C. The folding of the polypeptide chain
D. The interaction of multiple subunits
Answer: B
Rationale: Primary structure is defined as the specific order of amino acids in a
polypeptide chain.
8. Which of the following is a characteristic of prokaryotic cells?
A. Presence of a nucleus
B. Circular DNA located in a nucleoid
C. Membrane-bound organelles
D. Linear chromosomes
Answer: B
Rationale: Prokaryotes lack a nucleus and membrane-bound organelles, and typically have
a single circular chromosome.
1. Which organelle is responsible for the synthesis of lipids and the
detoxification of drugs?
A. Rough Endoplasmic Reticulum
B. Lysosome
C. Golgi Apparatus
D. Smooth Endoplasmic Reticulum
Answer: D
Rationale: The smooth ER is involved in lipid synthesis, carbohydrate metabolism, and
detoxification, unlike the rough ER which is studded with ribosomes for protein synthesis.
2. The limit of resolution of a standard light microscope is approximately:
A. 20 nanometers
B. 2.0 micrometers
C. 0.2 micrometers
D. 200 micrometers
Answer: C
Rationale: The resolution limit of light microscopy is roughly half the wavelength of visible
light, which is about 200 nm or 0.2 micrometers.
,3. Which of the following model organisms is commonly used to study the
genetics of development in a multicellular animal?
A. Escherichia coli
B. Drosophila melanogaster
C. Saccharomyces cerevisiae
D. Arabidopsis thaliana
Answer: B
Rationale: Drosophila melanogaster (the fruit fly) is a classic model for developmental
biology and genetics.
4. What type of bond is formed by the equal sharing of electrons between two
atoms?
A. Ionic bond
B. Nonpolar covalent bond
C. Hydrogen bond
D. Polar covalent bond
Answer: B
Rationale: Nonpolar covalent bonds occur when atoms share electrons equally, typically
between atoms of similar electronegativity.
5. Water molecules are polar because:
A. Oxygen and hydrogen have the same electronegativity
B. Hydrogen is more electronegative than oxygen
C. They contain ionic bonds
D. Oxygen is more electronegative than hydrogen
Answer: D
Rationale: The high electronegativity of oxygen causes an unequal distribution of charge,
making the molecule polar.
, 6. Which macromolecule is primarily responsible for the storage of genetic
information?
A. Proteins
B. Nucleic Acids
C. Carbohydrates
D. Lipids
Answer: B
Rationale: Nucleic acids (DNA and RNA) are the molecules that store and transmit genetic
information.
7. The primary structure of a protein refers to:
A. Alpha helices and beta sheets
B. The linear sequence of amino acids
C. The folding of the polypeptide chain
D. The interaction of multiple subunits
Answer: B
Rationale: Primary structure is defined as the specific order of amino acids in a
polypeptide chain.
8. Which of the following is a characteristic of prokaryotic cells?
A. Presence of a nucleus
B. Circular DNA located in a nucleoid
C. Membrane-bound organelles
D. Linear chromosomes
Answer: B
Rationale: Prokaryotes lack a nucleus and membrane-bound organelles, and typically have
a single circular chromosome.
