WGU C190 Introduction to Biology –
Comprehensive Actual Exam | 150 Verified
Questions & Answers | 2026 Edition | Concept
Mastery with Rationales | INSTANT
DOWNLOAND PDF
Overview:
This Real exam is designed to help students prepare for the WGU C190 Objective Assessment
(OA) by covering all major domains of the course:
Cell & Molecular Biology – Cell structure, organelles, macromolecules, DNA/RNA,
protein synthesis, enzymes, membranes.
Genetics & Inheritance – Mendelian genetics, inheritance patterns, mutations,
molecular techniques, population genetics.
Evolution, Ecology & Behavior – Natural selection, speciation, population dynamics,
ecosystems, biomes, behavior, adaptation.
Physiology & Anatomy – Human organ systems, homeostasis, hormones, muscles,
nervous system, circulation, respiration, excretion.
Microbiology & Immunology – Microbial structure, growth, pathogens, immune
responses, vaccines, lab techniques.
Energy, Photosynthesis, Respiration & Lab Skills – Metabolic pathways, energy
production, photosynthesis, experimental design, lab safety, data interpretation.
Cell & Molecular Biology (1–30)
1. Which organelle is primarily responsible for ATP production in
eukaryotic cells?
A) Golgi apparatus
B) Mitochondrion
C) Lysosome
D) Endoplasmic reticulum
, Answer: B. Rationale: Mitochondria perform oxidative
phosphorylation to synthesize ATP.
2. The fluid mosaic model describes which cell component?
A) Cytoskeleton
B) Plasma membrane
C) Nucleus
D) Endoplasmic reticulum
Answer: B. Rationale: Plasma membrane is a fluid lipid bilayer
with embedded proteins.
3. Which bond stabilizes the secondary structure (α-helix, β-sheet)
of proteins?
A) Peptide bonds
B) Ionic bonds
C) Hydrogen bonds
D) Disulfide bonds
Answer: C. Rationale: Hydrogen bonds between backbone groups
stabilize secondary structure.
4. During DNA replication, which enzyme synthesizes the new DNA
strand?
A) DNA ligase
B) DNA polymerase
C) RNA polymerase
D) Topoisomerase
Answer: B. Rationale: DNA polymerase adds nucleotides
complementary to the template.
5. Which RNA type carries amino acids to the ribosome?
A) mRNA
B) rRNA
C) tRNA
, D) snRNA
Answer: C. Rationale: tRNA has the anticodon and carries specific
amino acids.
6. What is the central dogma of molecular biology?
A) DNA → RNA → Protein
B) Protein → RNA → DNA
C) RNA → DNA → Protein
D) DNA → Protein → RNA
Answer: A. Rationale: Genetic information is transcribed to RNA
and translated to protein.
7. A noncompetitive inhibitor decreases enzyme activity by:
A) Binding the active site permanently
B) Increasing substrate concentration
C) Binding to an allosteric site changing enzyme shape
D) Acting as a reversible substrate analog
Answer: C. Rationale: Noncompetitive inhibitors bind elsewhere
to alter conformation.
8. Which process occurs in the nucleus of eukaryotes?
A) Translation
B) Glycolysis
C) Transcription
D) Electron transport chain
Answer: C. Rationale: Transcription (DNA → RNA) occurs in the
nucleus.
9. The bond between two monosaccharides is called a:
A) Peptide bond
B) Glycosidic bond
C) Ester bond
, D) Phosphodiester bond
Answer: B. Rationale: Glycosidic bonds link sugar monomers.
10. Which statement about prokaryotes is true?
A) They have membrane-bound nuclei.
B) They contain mitochondria.
C) Their DNA is circular and not in a nucleus.
D) They always have multiple linear chromosomes.
Answer: C. Rationale: Prokaryotic DNA is typically circular and
cytoplasmic.
11. Osmosis is the movement of:
A) Solute down its concentration gradient
B) Water across a semipermeable membrane toward higher
solute concentration
C) Water toward lower solute concentration
D) Ions via active transport
Answer: B. Rationale: Osmosis moves water to equalize solute
concentration.
12. Which structure is present in plant but not animal cells?
A) Ribosome
B) Cell wall
C) Golgi apparatus
D) Plasma membrane
Answer: B. Rationale: Plant cells have a rigid cell wall (cellulose).
13. An observer sees a cell undergoing metaphase. Which is
true?
A) Chromosomes are at spindle poles
B) Chromosomes align at metaphase plate
C) Sister chromatids separate
D) Nuclear envelope reforms
Comprehensive Actual Exam | 150 Verified
Questions & Answers | 2026 Edition | Concept
Mastery with Rationales | INSTANT
DOWNLOAND PDF
Overview:
This Real exam is designed to help students prepare for the WGU C190 Objective Assessment
(OA) by covering all major domains of the course:
Cell & Molecular Biology – Cell structure, organelles, macromolecules, DNA/RNA,
protein synthesis, enzymes, membranes.
Genetics & Inheritance – Mendelian genetics, inheritance patterns, mutations,
molecular techniques, population genetics.
Evolution, Ecology & Behavior – Natural selection, speciation, population dynamics,
ecosystems, biomes, behavior, adaptation.
Physiology & Anatomy – Human organ systems, homeostasis, hormones, muscles,
nervous system, circulation, respiration, excretion.
Microbiology & Immunology – Microbial structure, growth, pathogens, immune
responses, vaccines, lab techniques.
Energy, Photosynthesis, Respiration & Lab Skills – Metabolic pathways, energy
production, photosynthesis, experimental design, lab safety, data interpretation.
Cell & Molecular Biology (1–30)
1. Which organelle is primarily responsible for ATP production in
eukaryotic cells?
A) Golgi apparatus
B) Mitochondrion
C) Lysosome
D) Endoplasmic reticulum
, Answer: B. Rationale: Mitochondria perform oxidative
phosphorylation to synthesize ATP.
2. The fluid mosaic model describes which cell component?
A) Cytoskeleton
B) Plasma membrane
C) Nucleus
D) Endoplasmic reticulum
Answer: B. Rationale: Plasma membrane is a fluid lipid bilayer
with embedded proteins.
3. Which bond stabilizes the secondary structure (α-helix, β-sheet)
of proteins?
A) Peptide bonds
B) Ionic bonds
C) Hydrogen bonds
D) Disulfide bonds
Answer: C. Rationale: Hydrogen bonds between backbone groups
stabilize secondary structure.
4. During DNA replication, which enzyme synthesizes the new DNA
strand?
A) DNA ligase
B) DNA polymerase
C) RNA polymerase
D) Topoisomerase
Answer: B. Rationale: DNA polymerase adds nucleotides
complementary to the template.
5. Which RNA type carries amino acids to the ribosome?
A) mRNA
B) rRNA
C) tRNA
, D) snRNA
Answer: C. Rationale: tRNA has the anticodon and carries specific
amino acids.
6. What is the central dogma of molecular biology?
A) DNA → RNA → Protein
B) Protein → RNA → DNA
C) RNA → DNA → Protein
D) DNA → Protein → RNA
Answer: A. Rationale: Genetic information is transcribed to RNA
and translated to protein.
7. A noncompetitive inhibitor decreases enzyme activity by:
A) Binding the active site permanently
B) Increasing substrate concentration
C) Binding to an allosteric site changing enzyme shape
D) Acting as a reversible substrate analog
Answer: C. Rationale: Noncompetitive inhibitors bind elsewhere
to alter conformation.
8. Which process occurs in the nucleus of eukaryotes?
A) Translation
B) Glycolysis
C) Transcription
D) Electron transport chain
Answer: C. Rationale: Transcription (DNA → RNA) occurs in the
nucleus.
9. The bond between two monosaccharides is called a:
A) Peptide bond
B) Glycosidic bond
C) Ester bond
, D) Phosphodiester bond
Answer: B. Rationale: Glycosidic bonds link sugar monomers.
10. Which statement about prokaryotes is true?
A) They have membrane-bound nuclei.
B) They contain mitochondria.
C) Their DNA is circular and not in a nucleus.
D) They always have multiple linear chromosomes.
Answer: C. Rationale: Prokaryotic DNA is typically circular and
cytoplasmic.
11. Osmosis is the movement of:
A) Solute down its concentration gradient
B) Water across a semipermeable membrane toward higher
solute concentration
C) Water toward lower solute concentration
D) Ions via active transport
Answer: B. Rationale: Osmosis moves water to equalize solute
concentration.
12. Which structure is present in plant but not animal cells?
A) Ribosome
B) Cell wall
C) Golgi apparatus
D) Plasma membrane
Answer: B. Rationale: Plant cells have a rigid cell wall (cellulose).
13. An observer sees a cell undergoing metaphase. Which is
true?
A) Chromosomes are at spindle poles
B) Chromosomes align at metaphase plate
C) Sister chromatids separate
D) Nuclear envelope reforms
