WGU C180 BIOLOGY COMPREHENSIVE
EXAM PREP QUESTIONS AND
ANSWERS
1. Which of the following describes the secondary structure of a protein?
A. The sequence of amino acids in a polypeptide chain.
B. Local folding patterns such as alpha-helices and beta-pleated sheets.
C. The three-dimensional folding due to side chain interactions.
D. The arrangement of multiple polypeptide subunits.
Answer: B
Conceptual Explanation: Secondary structure refers to local folded structures that form
within a polypeptide due to interactions between atoms of the backbone.
2. In the process of DNA replication, which enzyme is responsible for unwinding the double
helix?
A. Helicase
B. DNA Polymerase
C. Ligase
D. Primase
,Answer: A
Conceptual Explanation: Helicase is the enzyme that breaks the hydrogen bonds between
the nitrogenous bases to unzip the DNA strands.
3. Which organelle is responsible for the synthesis of lipids and the detoxification of harmful
substances?
A. Rough Endoplasmic Reticulum
B. Smooth Endoplasmic Reticulum
C. Golgi Apparatus
D. Lysosome
Answer: B
Conceptual Explanation: The Smooth ER is specialized for lipid synthesis, carbohydrate
metabolism, and detoxification.
4. During which phase of meiosis does crossing over occur?
A. Anaphase I
B. Metaphase I
C. Prophase II
D. Prophase I
Answer: D
, Conceptual Explanation: Crossing over, the exchange of genetic material between
homologous chromosomes, occurs during Prophase I.
5. What is the primary function of the Calvin Cycle in photosynthesis?
A. To fix carbon dioxide into organic sugar molecules.
B. To produce ATP and NADPH.
C. To split water and release oxygen.
D. To absorb light energy using chlorophyll.
Answer: A
Conceptual Explanation: The Calvin Cycle is the light-independent reaction that uses ATP
and NADPH to convert CO2 into G3P.
6. A solution with a higher solute concentration than the inside of a cell is described as:
A. Isotonic
B. Hypotonic
C. Equilibrium
D. Hypertonic
Answer: D
Conceptual Explanation: Hypertonic solutions have a higher concentration of solutes,
causing water to leave the cell via osmosis.
EXAM PREP QUESTIONS AND
ANSWERS
1. Which of the following describes the secondary structure of a protein?
A. The sequence of amino acids in a polypeptide chain.
B. Local folding patterns such as alpha-helices and beta-pleated sheets.
C. The three-dimensional folding due to side chain interactions.
D. The arrangement of multiple polypeptide subunits.
Answer: B
Conceptual Explanation: Secondary structure refers to local folded structures that form
within a polypeptide due to interactions between atoms of the backbone.
2. In the process of DNA replication, which enzyme is responsible for unwinding the double
helix?
A. Helicase
B. DNA Polymerase
C. Ligase
D. Primase
,Answer: A
Conceptual Explanation: Helicase is the enzyme that breaks the hydrogen bonds between
the nitrogenous bases to unzip the DNA strands.
3. Which organelle is responsible for the synthesis of lipids and the detoxification of harmful
substances?
A. Rough Endoplasmic Reticulum
B. Smooth Endoplasmic Reticulum
C. Golgi Apparatus
D. Lysosome
Answer: B
Conceptual Explanation: The Smooth ER is specialized for lipid synthesis, carbohydrate
metabolism, and detoxification.
4. During which phase of meiosis does crossing over occur?
A. Anaphase I
B. Metaphase I
C. Prophase II
D. Prophase I
Answer: D
, Conceptual Explanation: Crossing over, the exchange of genetic material between
homologous chromosomes, occurs during Prophase I.
5. What is the primary function of the Calvin Cycle in photosynthesis?
A. To fix carbon dioxide into organic sugar molecules.
B. To produce ATP and NADPH.
C. To split water and release oxygen.
D. To absorb light energy using chlorophyll.
Answer: A
Conceptual Explanation: The Calvin Cycle is the light-independent reaction that uses ATP
and NADPH to convert CO2 into G3P.
6. A solution with a higher solute concentration than the inside of a cell is described as:
A. Isotonic
B. Hypotonic
C. Equilibrium
D. Hypertonic
Answer: D
Conceptual Explanation: Hypertonic solutions have a higher concentration of solutes,
causing water to leave the cell via osmosis.
