WGU C190 Introduction to Biology ACTUAL
EXAM 2025/2026 | Objective Assessment OA
Exam Review | Complete Test | Brand New |
Verified Q&A | Pass Guaranteed - A+ Graded
SECTION 1: THE NATURE OF SCIENCE AND BASIC CHEMISTRY
(25 Questions)
Q1: A scientist hypothesizes that a new drug will lower blood pressure. In a controlled experiment,
one group receives the drug and another group receives a placebo. What is the independent variable
in this experiment?
● A. Blood pressure
● B. The placebo
● C. The new drug [CORRECT]
● D. The participants
Rationale: The independent variable is the factor deliberately manipulated by the researcher (the drug
being tested). Blood pressure (A) is the dependent variable—the outcome being measured. The
placebo (B) serves as a control condition for comparison. Participants (D) are the experimental
subjects, not a variable.
WGU Note: Distinguishing independent vs. dependent variables appears on virtually every OA.
Remember: Independent = what YOU change; Dependent = what you MEASURE.
,Q2: A solution has a pH of 3. This solution is best described as:
● A. Neutral
● B. Strongly acidic [CORRECT]
● C. Weakly basic
● D. Strongly basic
Rationale: The pH scale ranges from 0 (most acidic) to 14 (most basic), with 7 being neutral. Values
below 7 indicate acidity, with lower numbers representing stronger acids. A pH of 3 is strongly acidic.
Neutral (A) is pH 7. Basic solutions (C, D) have pH values above 7.
Q3: Which of the following is NOT a characteristic of living organisms?
● A. Homeostasis
● B. Reproduction
● C. Growth and development
● D. Random movement [CORRECT]
Rationale: All living organisms display: organization, energy use, homeostasis (A), growth and
development (C), reproduction (B), response to stimuli, and adaptation/evolution. Random
movement (D) is not a defining characteristic—living things respond to specific stimuli purposefully,
not randomly.
Q4: Which level of biological organization is represented by a group of cells working together to
perform a specific function?
● A. Organ
, ● B. Tissue [CORRECT]
● C. Organ system
● D. Organism
Rationale: Biological organization progresses: atoms → molecules → organelles → cells → tissues
(groups of similar cells) → organs (B) → organ systems (C) → organisms (D). A tissue is specifically
defined as a group of cells working together to perform a specific function.
Q5: An atom has 8 protons, 8 neutrons, and 8 electrons. What is its mass number?
● A. 8
● B. 16 [CORRECT]
● C. 24
● D. 16
Rationale: Mass number = protons + neutrons. This atom has 8 protons + 8 neutrons = 16. Atomic
number (number of protons) is 8, identifying this as oxygen. Electrons do not contribute significantly
to atomic mass.
Q6: Isotopes of an element differ in their number of:
● A. Protons
● B. Electrons
● C. Neutrons [CORRECT]
● D. Shells
Rationale: Isotopes are variants of the same element (same atomic number/protons) with different
numbers of neutrons, resulting in different mass numbers. Changing protons (A) creates a different
element. Changing electrons (B) creates ions. Shells (D) are energy levels, not subatomic particles.
, Q7: Which type of chemical bond involves the sharing of electron pairs between atoms?
● A. Ionic bond
● B. Covalent bond [CORRECT]
● C. Hydrogen bond
● D. Van der Waals force
Rationale: Covalent bonds involve electron sharing between atoms to fill valence shells. Ionic bonds
(A) involve electron transfer creating ions. Hydrogen bonds (C) are weak attractions between
hydrogen and electronegative atoms. Van der Waals forces (D) are weak intermolecular attractions.
Q8: Water molecules exhibit cohesion due to:
● A. Ionic bonding between molecules
● B. Hydrogen bonding between molecules [CORRECT]
● C. Covalent bonding between molecules
● D. Peptide bonding between molecules
Rationale: Cohesion (water molecules sticking to each other) results from hydrogen bonds between
the slightly positive hydrogen of one water molecule and the slightly negative oxygen of another.
Covalent bonds (C) hold the H and O atoms together within each molecule, not between molecules.
Q9: Which property of water allows it to absorb significant heat without large temperature changes?
● A. High surface tension
● B. High specific heat capacity [CORRECT]
● C. Universal solvent properties
● D. Density anomaly
EXAM 2025/2026 | Objective Assessment OA
Exam Review | Complete Test | Brand New |
Verified Q&A | Pass Guaranteed - A+ Graded
SECTION 1: THE NATURE OF SCIENCE AND BASIC CHEMISTRY
(25 Questions)
Q1: A scientist hypothesizes that a new drug will lower blood pressure. In a controlled experiment,
one group receives the drug and another group receives a placebo. What is the independent variable
in this experiment?
● A. Blood pressure
● B. The placebo
● C. The new drug [CORRECT]
● D. The participants
Rationale: The independent variable is the factor deliberately manipulated by the researcher (the drug
being tested). Blood pressure (A) is the dependent variable—the outcome being measured. The
placebo (B) serves as a control condition for comparison. Participants (D) are the experimental
subjects, not a variable.
WGU Note: Distinguishing independent vs. dependent variables appears on virtually every OA.
Remember: Independent = what YOU change; Dependent = what you MEASURE.
,Q2: A solution has a pH of 3. This solution is best described as:
● A. Neutral
● B. Strongly acidic [CORRECT]
● C. Weakly basic
● D. Strongly basic
Rationale: The pH scale ranges from 0 (most acidic) to 14 (most basic), with 7 being neutral. Values
below 7 indicate acidity, with lower numbers representing stronger acids. A pH of 3 is strongly acidic.
Neutral (A) is pH 7. Basic solutions (C, D) have pH values above 7.
Q3: Which of the following is NOT a characteristic of living organisms?
● A. Homeostasis
● B. Reproduction
● C. Growth and development
● D. Random movement [CORRECT]
Rationale: All living organisms display: organization, energy use, homeostasis (A), growth and
development (C), reproduction (B), response to stimuli, and adaptation/evolution. Random
movement (D) is not a defining characteristic—living things respond to specific stimuli purposefully,
not randomly.
Q4: Which level of biological organization is represented by a group of cells working together to
perform a specific function?
● A. Organ
, ● B. Tissue [CORRECT]
● C. Organ system
● D. Organism
Rationale: Biological organization progresses: atoms → molecules → organelles → cells → tissues
(groups of similar cells) → organs (B) → organ systems (C) → organisms (D). A tissue is specifically
defined as a group of cells working together to perform a specific function.
Q5: An atom has 8 protons, 8 neutrons, and 8 electrons. What is its mass number?
● A. 8
● B. 16 [CORRECT]
● C. 24
● D. 16
Rationale: Mass number = protons + neutrons. This atom has 8 protons + 8 neutrons = 16. Atomic
number (number of protons) is 8, identifying this as oxygen. Electrons do not contribute significantly
to atomic mass.
Q6: Isotopes of an element differ in their number of:
● A. Protons
● B. Electrons
● C. Neutrons [CORRECT]
● D. Shells
Rationale: Isotopes are variants of the same element (same atomic number/protons) with different
numbers of neutrons, resulting in different mass numbers. Changing protons (A) creates a different
element. Changing electrons (B) creates ions. Shells (D) are energy levels, not subatomic particles.
, Q7: Which type of chemical bond involves the sharing of electron pairs between atoms?
● A. Ionic bond
● B. Covalent bond [CORRECT]
● C. Hydrogen bond
● D. Van der Waals force
Rationale: Covalent bonds involve electron sharing between atoms to fill valence shells. Ionic bonds
(A) involve electron transfer creating ions. Hydrogen bonds (C) are weak attractions between
hydrogen and electronegative atoms. Van der Waals forces (D) are weak intermolecular attractions.
Q8: Water molecules exhibit cohesion due to:
● A. Ionic bonding between molecules
● B. Hydrogen bonding between molecules [CORRECT]
● C. Covalent bonding between molecules
● D. Peptide bonding between molecules
Rationale: Cohesion (water molecules sticking to each other) results from hydrogen bonds between
the slightly positive hydrogen of one water molecule and the slightly negative oxygen of another.
Covalent bonds (C) hold the H and O atoms together within each molecule, not between molecules.
Q9: Which property of water allows it to absorb significant heat without large temperature changes?
● A. High surface tension
● B. High specific heat capacity [CORRECT]
● C. Universal solvent properties
● D. Density anomaly
