WGU C190 INTRODUCTION TO
BIOLOGY COMPREHENSIVE EXAM
2026/2027 QUESTIONS AND ANSWERS
1. Which property of water is primarily responsible for its ability to resist drastic temperature
changes, supporting homeostatic regulation in organisms?
A. High specific heat
B. High heat of vaporization
C. Cohesive strength
D. Surface tension
Answer: A
Conceptual Explanation: Water’s high specific heat capacity means it can absorb a large
amount of heat energy with only a slight change in temperature, which stabilizes internal
temperatures in living things.
2. In a dehydration synthesis reaction between two amino acids, which specific bond is
formed?
A. Glycosidic linkage
,B. Phosphodiester bond
C. Ester linkage
D. Peptide bond
Answer: D
Conceptual Explanation: A peptide bond is a covalent bond formed between the carboxyl
group of one amino acid and the amino group of another, releasing water.
3. Which level of protein structure is characterized by the formation of alpha-helices and
beta-pleated sheets via hydrogen bonding?
A. Primary structure
B. Quaternary structure
C. Tertiary structure
D. Secondary structure
Answer: D
Conceptual Explanation: Secondary structure refers to the local folding of the polypeptide
chain into shapes like helices or sheets, stabilized solely by hydrogen bonds along the
backbone.
4. An enzyme is inhibited by a molecule that binds to a site other than the active site,
changing the enzyme’s shape. This is an example of:
A. Competitive inhibition
, B. Allosteric (non-competitive) inhibition
C. Irreversible inhibition
D. Feedback activation
Answer: B
Conceptual Explanation: Non-competitive or allosteric inhibition occurs when an
inhibitor binds to an allosteric site, altering the enzyme’s conformation so the substrate
cannot bind efficiently.
5. What is the primary role of the nucleolus within a eukaryotic cell?
A. Synthesis of messenger RNA
B. Assembly of ribosomal subunits
C. Storage of genetic information
D. Regulation of nuclear transport
Answer: B
Conceptual Explanation: The nucleolus is a dense region within the nucleus where
ribosomal RNA (rRNA) is synthesized and combined with proteins to form ribosome
subunits.
6. Which organelle is responsible for the modification, sorting, and packaging of proteins for
secretion?
A. Endoplasmic Reticulum
BIOLOGY COMPREHENSIVE EXAM
2026/2027 QUESTIONS AND ANSWERS
1. Which property of water is primarily responsible for its ability to resist drastic temperature
changes, supporting homeostatic regulation in organisms?
A. High specific heat
B. High heat of vaporization
C. Cohesive strength
D. Surface tension
Answer: A
Conceptual Explanation: Water’s high specific heat capacity means it can absorb a large
amount of heat energy with only a slight change in temperature, which stabilizes internal
temperatures in living things.
2. In a dehydration synthesis reaction between two amino acids, which specific bond is
formed?
A. Glycosidic linkage
,B. Phosphodiester bond
C. Ester linkage
D. Peptide bond
Answer: D
Conceptual Explanation: A peptide bond is a covalent bond formed between the carboxyl
group of one amino acid and the amino group of another, releasing water.
3. Which level of protein structure is characterized by the formation of alpha-helices and
beta-pleated sheets via hydrogen bonding?
A. Primary structure
B. Quaternary structure
C. Tertiary structure
D. Secondary structure
Answer: D
Conceptual Explanation: Secondary structure refers to the local folding of the polypeptide
chain into shapes like helices or sheets, stabilized solely by hydrogen bonds along the
backbone.
4. An enzyme is inhibited by a molecule that binds to a site other than the active site,
changing the enzyme’s shape. This is an example of:
A. Competitive inhibition
, B. Allosteric (non-competitive) inhibition
C. Irreversible inhibition
D. Feedback activation
Answer: B
Conceptual Explanation: Non-competitive or allosteric inhibition occurs when an
inhibitor binds to an allosteric site, altering the enzyme’s conformation so the substrate
cannot bind efficiently.
5. What is the primary role of the nucleolus within a eukaryotic cell?
A. Synthesis of messenger RNA
B. Assembly of ribosomal subunits
C. Storage of genetic information
D. Regulation of nuclear transport
Answer: B
Conceptual Explanation: The nucleolus is a dense region within the nucleus where
ribosomal RNA (rRNA) is synthesized and combined with proteins to form ribosome
subunits.
6. Which organelle is responsible for the modification, sorting, and packaging of proteins for
secretion?
A. Endoplasmic Reticulum
