WGU C190 Intro to Biology OA Exam 2026–2027 | Western
Governors University Introduction to Biology Objective
Assessment Study Guide, Biology Practice Questions with
Answers and Rationales, Cell Biology, Genetics, Evolution,
Ecology, Chemistry of Life and Scientific Method Review
Question 1: Which subatomic particle carries a negative charge and is found in
shells outside the atomic nucleus?
A. Proton
B. Neutron
C. Electron
D. Positron
CORRECT ANSWER: C. Electron
Rationale: Electrons are negatively charged subatomic particles that occupy
energy shells surrounding the nucleus. Protons are positively charged and located
in the nucleus, while neutrons are neutral and also reside in the nucleus.
Question 2: Which type of chemical bond is formed when one atom transfers an
electron to another atom?
A. Covalent bond
B. Ionic bond
C. Hydrogen bond
D. Peptide bond
CORRECT ANSWER: B. Ionic bond
Rationale: Ionic bonds result from the complete transfer of electrons from one
atom to another, creating oppositely charged ions that attract each other.
Covalent bonds involve electron sharing, hydrogen bonds are weak attractions
between partial charges, and peptide bonds link amino acids.
Question 3: Which property of water is responsible for the formation of droplets
on a leaf's surface?
A. Adhesion
B. Cohesion
C. High specific heat
D. Universal solvent capability
,CORRECT ANSWER: B. Cohesion
Rationale: Cohesion refers to the attraction between water molecules
themselves, which causes water to form beads or droplets. Adhesion is the
attraction between water and other surfaces, while high specific heat relates to
temperature stability.
Question 4: A biological polymer consists of 358 amino acids linked together
covalently. What is this polymer?
A. Polysaccharide
B. Nucleic acid
C. Protein
D. Lipid
CORRECT ANSWER: C. Protein
Rationale: Proteins are polymers composed of amino acid monomers linked by
peptide bonds. Polysaccharides are made of sugars, nucleic acids of nucleotides,
and lipids are not typically classified as polymers of amino acids.
Question 5: Which organelle is responsible for producing the majority of ATP in
a eukaryotic cell?
A. Nucleus
B. Ribosome
C. Mitochondrion
D. Golgi apparatus
CORRECT ANSWER: C. Mitochondrion
Rationale: The mitochondrion is the site of aerobic cellular respiration and
oxidative phosphorylation, producing most of the cell's ATP. Ribosomes
synthesize proteins, and the Golgi apparatus modifies and packages proteins.
Question 6: What is the primary function of chloroplasts in plant cells?
A. Cellular respiration
B. Protein synthesis
C. Photosynthesis
D. Lipid storage
,CORRECT ANSWER: C. Photosynthesis
Rationale: Chloroplasts capture light energy and convert it into chemical energy
through photosynthesis, producing glucose. Mitochondria perform cellular
respiration, and ribosomes handle protein synthesis.
Question 7: Which characteristic of living organisms is demonstrated when a
sunflower turns its head to face the sun?
A. Reproduction
B. Growth and development
C. Response to stimuli
D. Energy utilization
CORRECT ANSWER: C. Response to stimuli
Rationale: The sunflower's movement in response to light direction is an example
of responding to environmental stimuli (phototropism). This behavior allows the
plant to maximize light absorption for photosynthesis.
Question 8: What is the independent variable in an experiment testing the
effect of light intensity on flower size?
A. Flower size
B. Light intensity
C. Orchid species
D. Soil type
CORRECT ANSWER: B. Light intensity
Rationale: The independent variable is the factor that the researcher manipulates
to observe its effect. Light intensity is being varied, while flower size is the
dependent variable being measured. Orchid species and soil type would be
controlled variables.
Question 9: Which of the following is an example of a qualitative observation?
A. The plant grew 15 centimeters in one month
B. The solution has a temperature of 37 degrees Celsius
C. The leaves turned yellow and wilted
D. The fish weighs 200 grams
, CORRECT ANSWER: C. The leaves turned yellow and wilted
Rationale: Qualitative observations are descriptive and non-numerical, focusing
on qualities or characteristics. "Yellow and wilted" describes the condition of the
leaves without using measurements. The other options are quantitative
observations.
Question 10: A hypothesis is best described as:
A. An educated guess that has been proven
B. A tentative explanation for an observation that can be tested
C. A fact that is universally accepted
D. The final conclusion of an experiment
CORRECT ANSWER: B. A tentative explanation for an observation that can be
tested
Rationale: A hypothesis is a proposed explanation for a phenomenon that is
testable through experimentation or further observation. It is not proven, nor is it
a fact or final conclusion. Hypotheses are refined or rejected based on
experimental results.
Question 11: What is the basic unit of matter?
A. Molecule
B. Cell
C. Atom
D. Electron
CORRECT ANSWER: C. Atom
Rationale: The atom is the smallest unit of matter that retains the properties of an
element. Cells are the basic unit of life, while molecules are two or more atoms
bonded together.
Question 12: Which level of biological organization consists of all individuals of a
species living within a specific area?
A. Community
B. Population
Governors University Introduction to Biology Objective
Assessment Study Guide, Biology Practice Questions with
Answers and Rationales, Cell Biology, Genetics, Evolution,
Ecology, Chemistry of Life and Scientific Method Review
Question 1: Which subatomic particle carries a negative charge and is found in
shells outside the atomic nucleus?
A. Proton
B. Neutron
C. Electron
D. Positron
CORRECT ANSWER: C. Electron
Rationale: Electrons are negatively charged subatomic particles that occupy
energy shells surrounding the nucleus. Protons are positively charged and located
in the nucleus, while neutrons are neutral and also reside in the nucleus.
Question 2: Which type of chemical bond is formed when one atom transfers an
electron to another atom?
A. Covalent bond
B. Ionic bond
C. Hydrogen bond
D. Peptide bond
CORRECT ANSWER: B. Ionic bond
Rationale: Ionic bonds result from the complete transfer of electrons from one
atom to another, creating oppositely charged ions that attract each other.
Covalent bonds involve electron sharing, hydrogen bonds are weak attractions
between partial charges, and peptide bonds link amino acids.
Question 3: Which property of water is responsible for the formation of droplets
on a leaf's surface?
A. Adhesion
B. Cohesion
C. High specific heat
D. Universal solvent capability
,CORRECT ANSWER: B. Cohesion
Rationale: Cohesion refers to the attraction between water molecules
themselves, which causes water to form beads or droplets. Adhesion is the
attraction between water and other surfaces, while high specific heat relates to
temperature stability.
Question 4: A biological polymer consists of 358 amino acids linked together
covalently. What is this polymer?
A. Polysaccharide
B. Nucleic acid
C. Protein
D. Lipid
CORRECT ANSWER: C. Protein
Rationale: Proteins are polymers composed of amino acid monomers linked by
peptide bonds. Polysaccharides are made of sugars, nucleic acids of nucleotides,
and lipids are not typically classified as polymers of amino acids.
Question 5: Which organelle is responsible for producing the majority of ATP in
a eukaryotic cell?
A. Nucleus
B. Ribosome
C. Mitochondrion
D. Golgi apparatus
CORRECT ANSWER: C. Mitochondrion
Rationale: The mitochondrion is the site of aerobic cellular respiration and
oxidative phosphorylation, producing most of the cell's ATP. Ribosomes
synthesize proteins, and the Golgi apparatus modifies and packages proteins.
Question 6: What is the primary function of chloroplasts in plant cells?
A. Cellular respiration
B. Protein synthesis
C. Photosynthesis
D. Lipid storage
,CORRECT ANSWER: C. Photosynthesis
Rationale: Chloroplasts capture light energy and convert it into chemical energy
through photosynthesis, producing glucose. Mitochondria perform cellular
respiration, and ribosomes handle protein synthesis.
Question 7: Which characteristic of living organisms is demonstrated when a
sunflower turns its head to face the sun?
A. Reproduction
B. Growth and development
C. Response to stimuli
D. Energy utilization
CORRECT ANSWER: C. Response to stimuli
Rationale: The sunflower's movement in response to light direction is an example
of responding to environmental stimuli (phototropism). This behavior allows the
plant to maximize light absorption for photosynthesis.
Question 8: What is the independent variable in an experiment testing the
effect of light intensity on flower size?
A. Flower size
B. Light intensity
C. Orchid species
D. Soil type
CORRECT ANSWER: B. Light intensity
Rationale: The independent variable is the factor that the researcher manipulates
to observe its effect. Light intensity is being varied, while flower size is the
dependent variable being measured. Orchid species and soil type would be
controlled variables.
Question 9: Which of the following is an example of a qualitative observation?
A. The plant grew 15 centimeters in one month
B. The solution has a temperature of 37 degrees Celsius
C. The leaves turned yellow and wilted
D. The fish weighs 200 grams
, CORRECT ANSWER: C. The leaves turned yellow and wilted
Rationale: Qualitative observations are descriptive and non-numerical, focusing
on qualities or characteristics. "Yellow and wilted" describes the condition of the
leaves without using measurements. The other options are quantitative
observations.
Question 10: A hypothesis is best described as:
A. An educated guess that has been proven
B. A tentative explanation for an observation that can be tested
C. A fact that is universally accepted
D. The final conclusion of an experiment
CORRECT ANSWER: B. A tentative explanation for an observation that can be
tested
Rationale: A hypothesis is a proposed explanation for a phenomenon that is
testable through experimentation or further observation. It is not proven, nor is it
a fact or final conclusion. Hypotheses are refined or rejected based on
experimental results.
Question 11: What is the basic unit of matter?
A. Molecule
B. Cell
C. Atom
D. Electron
CORRECT ANSWER: C. Atom
Rationale: The atom is the smallest unit of matter that retains the properties of an
element. Cells are the basic unit of life, while molecules are two or more atoms
bonded together.
Question 12: Which level of biological organization consists of all individuals of a
species living within a specific area?
A. Community
B. Population
