WGU C190 INTRODUCTION TO
BIOLOGY FINAL EXAM PREP
QUESTIONS AND ANSWERS
1. Which of the following best describes the structural arrangement of the plasma
membrane?
A. A single layer of proteins with embedded phospholipids
B. A solid wall of cellulose with protein pores
C. A phospholipid bilayer with hydrophobic tails facing inward and hydrophilic heads
facing outward
D. A triple layer of carbohydrates and lipids
Answer: C
Conceptual Explanation: The plasma membrane is a fluid mosaic consisting of a
phospholipid bilayer where the hydrophobic tails are shielded from water and the
hydrophilic heads interact with the aqueous environment.
2. In the process of DNA replication, what is the specific function of the enzyme Helicase?
A. Synthesizing RNA primers
,B. Unwinding the DNA double helix by breaking hydrogen bonds
C. Relieving torsional strain ahead of the replication fork
D. Joining Okazaki fragments on the lagging strand
Answer: B
Conceptual Explanation: Helicase is responsible for ‘unzipping’ the DNA molecule by
breaking the hydrogen bonds between complementary base pairs.
3. During which phase of the cell cycle does DNA replication occur?
A. G1 Phase
B. G2 Phase
C. S Phase
D. M Phase
Answer: C
Conceptual Explanation: The S phase (Synthesis phase) of interphase is specifically when
DNA is replicated to ensure daughter cells receive a full set of chromosomes.
4. Which molecule serves as the primary electron carrier in the electron transport chain
during cellular respiration?
A. ATP
B. Glucose
, C. NADH
D. Pyruvate
Answer: C
Conceptual Explanation: NADH and FADH2 carry high-energy electrons to the electron
transport chain to facilitate the production of ATP.
5. Which of the following statements about the Calvin Cycle is correct?
A. It occurs in the thylakoid membrane and produces oxygen
B. It requires light directly to split water molecules
C. It is the first step of cellular respiration in mitochondria
D. It occurs in the stroma and uses ATP and NADPH to fix carbon dioxide into sugar
Answer: D
Conceptual Explanation: The Calvin Cycle (light-independent reactions) takes place in the
stroma of the chloroplast, using energy from the light reactions to synthesize G3P.
6. An organism that has two different alleles for a specific trait is referred to as:
A. Homozygous dominant
B. Homozygous recessive
C. Heterozygous
D. Hemizygous
BIOLOGY FINAL EXAM PREP
QUESTIONS AND ANSWERS
1. Which of the following best describes the structural arrangement of the plasma
membrane?
A. A single layer of proteins with embedded phospholipids
B. A solid wall of cellulose with protein pores
C. A phospholipid bilayer with hydrophobic tails facing inward and hydrophilic heads
facing outward
D. A triple layer of carbohydrates and lipids
Answer: C
Conceptual Explanation: The plasma membrane is a fluid mosaic consisting of a
phospholipid bilayer where the hydrophobic tails are shielded from water and the
hydrophilic heads interact with the aqueous environment.
2. In the process of DNA replication, what is the specific function of the enzyme Helicase?
A. Synthesizing RNA primers
,B. Unwinding the DNA double helix by breaking hydrogen bonds
C. Relieving torsional strain ahead of the replication fork
D. Joining Okazaki fragments on the lagging strand
Answer: B
Conceptual Explanation: Helicase is responsible for ‘unzipping’ the DNA molecule by
breaking the hydrogen bonds between complementary base pairs.
3. During which phase of the cell cycle does DNA replication occur?
A. G1 Phase
B. G2 Phase
C. S Phase
D. M Phase
Answer: C
Conceptual Explanation: The S phase (Synthesis phase) of interphase is specifically when
DNA is replicated to ensure daughter cells receive a full set of chromosomes.
4. Which molecule serves as the primary electron carrier in the electron transport chain
during cellular respiration?
A. ATP
B. Glucose
, C. NADH
D. Pyruvate
Answer: C
Conceptual Explanation: NADH and FADH2 carry high-energy electrons to the electron
transport chain to facilitate the production of ATP.
5. Which of the following statements about the Calvin Cycle is correct?
A. It occurs in the thylakoid membrane and produces oxygen
B. It requires light directly to split water molecules
C. It is the first step of cellular respiration in mitochondria
D. It occurs in the stroma and uses ATP and NADPH to fix carbon dioxide into sugar
Answer: D
Conceptual Explanation: The Calvin Cycle (light-independent reactions) takes place in the
stroma of the chloroplast, using energy from the light reactions to synthesize G3P.
6. An organism that has two different alleles for a specific trait is referred to as:
A. Homozygous dominant
B. Homozygous recessive
C. Heterozygous
D. Hemizygous
