WGU C190 BIOLOGY COMPREHENSIVE
EXAM QUESTIONS AND ANSWERS
1. Which of the following best describes the difference between a hypothesis and a scientific
theory?
A. A hypothesis is a proven fact, while a theory is an educated guess.
B. There is no difference; the terms are used interchangeably in the scientific community.
C. A hypothesis is used only in biology, while theories are used in all sciences.
D. A hypothesis is a narrow, testable explanation for a specific phenomenon, while a theory
is a broad explanation supported by a large body of evidence.
Answer: D
Conceptual Explanation: Hypotheses are specific, testable predictions. Theories are
comprehensive frameworks that have been rigorously tested and confirmed through
multiple lines of evidence.
2. Which property of water allows it to move upward through a plant’s xylem against gravity?
A. Cohesion and adhesion
B. Low density as a solid
,C. High specific heat
D. Universal solvent properties
Answer: A
Conceptual Explanation: Cohesion (water molecules sticking to each other) and adhesion
(water sticking to other surfaces) combine to create capillary action, enabling water to
climb through plant tissues.
3. Which macromolecule is primarily responsible for long-term energy storage and insulating
organs?
A. Lipids
B. Carbohydrates
C. Nucleic acids
D. Proteins
Answer: A
Conceptual Explanation: Lipids (fats) provide high-density energy storage and act as
thermal insulators and shock absorbers for internal organs.
4. What is the primary function of the rough endoplasmic reticulum (RER)?
A. ATP production
B. Detoxification of chemicals
C. Lipid metabolism
, D. Protein synthesis and modification
Answer: D
Conceptual Explanation: The RER is ‘rough’ because it is studded with ribosomes, which
synthesize proteins that are then processed within the RER.
5. Which level of protein structure involves the folding of the polypeptide chain into alpha-
helices and beta-pleated sheets?
A. Primary structure
B. Secondary structure
C. Tertiary structure
D. Quaternary structure
Answer: B
Conceptual Explanation: Secondary structure results from hydrogen bonding between
the peptide backbone, creating localized patterns like helices and sheets.
6. During which phase of the cell cycle is DNA replicated?
A. S phase
B. G1 phase
C. G2 phase
D. M phase
EXAM QUESTIONS AND ANSWERS
1. Which of the following best describes the difference between a hypothesis and a scientific
theory?
A. A hypothesis is a proven fact, while a theory is an educated guess.
B. There is no difference; the terms are used interchangeably in the scientific community.
C. A hypothesis is used only in biology, while theories are used in all sciences.
D. A hypothesis is a narrow, testable explanation for a specific phenomenon, while a theory
is a broad explanation supported by a large body of evidence.
Answer: D
Conceptual Explanation: Hypotheses are specific, testable predictions. Theories are
comprehensive frameworks that have been rigorously tested and confirmed through
multiple lines of evidence.
2. Which property of water allows it to move upward through a plant’s xylem against gravity?
A. Cohesion and adhesion
B. Low density as a solid
,C. High specific heat
D. Universal solvent properties
Answer: A
Conceptual Explanation: Cohesion (water molecules sticking to each other) and adhesion
(water sticking to other surfaces) combine to create capillary action, enabling water to
climb through plant tissues.
3. Which macromolecule is primarily responsible for long-term energy storage and insulating
organs?
A. Lipids
B. Carbohydrates
C. Nucleic acids
D. Proteins
Answer: A
Conceptual Explanation: Lipids (fats) provide high-density energy storage and act as
thermal insulators and shock absorbers for internal organs.
4. What is the primary function of the rough endoplasmic reticulum (RER)?
A. ATP production
B. Detoxification of chemicals
C. Lipid metabolism
, D. Protein synthesis and modification
Answer: D
Conceptual Explanation: The RER is ‘rough’ because it is studded with ribosomes, which
synthesize proteins that are then processed within the RER.
5. Which level of protein structure involves the folding of the polypeptide chain into alpha-
helices and beta-pleated sheets?
A. Primary structure
B. Secondary structure
C. Tertiary structure
D. Quaternary structure
Answer: B
Conceptual Explanation: Secondary structure results from hydrogen bonding between
the peptide backbone, creating localized patterns like helices and sheets.
6. During which phase of the cell cycle is DNA replicated?
A. S phase
B. G1 phase
C. G2 phase
D. M phase
