WGU C190 Introduction to Biology
Actual Exam 2026/2027 Complete
Questions and Answers with
Detailed Rationales - Pass
Guaranteed - A+ Graded
Basic Chemistry & Biological Molecules – 8 questions
Q1: Water has a high specific heat capacity, which means it takes a lot of energy to
change its temperature. Which of the following is a biological benefit of this property?
A. It causes water to freeze from the top down, insulating liquid water below.
B. It allows water to act as a universal solvent for polar molecules.
C. It helps organisms maintain a relatively stable internal temperature despite
environmental changes.
D. It enables water molecules to stick to each other through hydrogen bonds (cohesion).
Correct Answer: C
Rationale: The best answer is stabilizing internal temperature because water's ability to
absorb or release large amounts of heat with minimal temperature change acts as a
buffer against thermal fluctuations in organisms and the environment.
Q2: A student is testing substances in the lab and finds that a solution has a pH of 3. Is
this solution acidic, basic, or neutral?
A. Basic
B. Neutral
C. Acidic
D. Neither acidic nor basic
Correct Answer: C
Rationale: This choice is correct because the pH scale runs from 0 to 14, where values
below 7 are acidic, 7 is neutral, and values above 7 are basic (alkaline).
Q3: Sodium chloride (NaCl) is a common table salt. Which type of chemical bond holds
the sodium and chlorine ions together in this compound?
A. Covalent bond
,B. Hydrogen bond
C. Ionic bond
D. Polar covalent bond
Correct Answer: C
Rationale: This aligns with ionic bonding because sodium (a metal) transfers an electron
to chlorine (a nonmetal), resulting in oppositely charged ions that attract each other to
form a stable crystal lattice.
Q4: Carbohydrates are a major source of energy for the body. Which of the following
best describes the monomer (building block) of carbohydrates like starch and glycogen?
A. Fatty acid
B. Amino acid
C. Monosaccharide (simple sugar)
D. Nucleotide
Correct Answer: C
Rationale: The best answer is monosaccharide because complex carbohydrates
(polysaccharides) are long chains of linked sugar units (monosaccharides) like glucose.
Q5: A dietitian advises a patient to limit their intake of saturated fats found in animal
products. What is the chemical difference between saturated and unsaturated fats?
A. Saturated fats contain double bonds between carbons; unsaturated fats have single
bonds.
B. Saturated fats are liquids at room temperature; unsaturated fats are solids.
C. Saturated fats have the maximum number of hydrogen atoms bonded to carbons;
unsaturated fats have fewer hydrogens due to double bonds.
D. Saturated fats are composed primarily of unsaturated fatty acids.
Correct Answer: C
Rationale: This choice is correct because "saturated" means the carbon chains are
holding as many hydrogen atoms as possible (all single bonds), which typically makes
them solid at room temperature, unlike unsaturated fats which have kinks from double
bonds.
Q6: Proteins have a complex structure that determines their function. Which level of
protein structure describes the linear sequence of amino acids linked by peptide bonds?
A. Primary structure
B. Secondary structure
C. Tertiary structure
D. Quaternary structure
Correct Answer: A
Rationale: The best answer is primary structure because it refers specifically to the
unique order of amino acids in a polypeptide chain, akin to letters spelling a word.
, Q7: Adenosine triphosphate (ATP) is often called the "energy currency" of the cell.
Which type of biological molecule does ATP belong to?
A. Protein
B. Lipid
C. Nucleic acid
D. Carbohydrate
Correct Answer: C
Rationale: This aligns with molecular classification because ATP is a nucleotide
composed of a nitrogenous base (adenine), a sugar (ribose), and three phosphate
groups, making it part of the nucleic acid family.
Q8: Water molecules exhibit cohesion, meaning they tend to stick to each other. Which
property of water is directly responsible for this behavior?
A. Polarity of the water molecule
B. High specific heat
C. Lower density as a solid than liquid
D. High surface tension
Correct Answer: A
Rationale: This choice is correct because cohesion is caused by the polar nature of
water molecules; the slightly positive hydrogen of one molecule is attracted to the
slightly negative oxygen of another, creating hydrogen bonds between them.
Cell Structure, Function & Membrane Transport – 10 questions
Q9: While observing a sample under a microscope, a student identifies a cell that has a
nucleus and membrane-bound organelles but lacks a cell wall. This cell is most likely
from a(n):
A. Plant
B. Fungus
C. Bacterium
D. Animal
Correct Answer: D
Rationale: The best answer is animal because eukaryotic animal cells possess a
nucleus and organelles but do not have the rigid cell wall found in plants, fungi, and
most bacteria.
Q10: Which cellular organelle is responsible for producing ATP through cellular
respiration?
A. Ribosome
B. Smooth endoplasmic reticulum
C. Mitochondria
Actual Exam 2026/2027 Complete
Questions and Answers with
Detailed Rationales - Pass
Guaranteed - A+ Graded
Basic Chemistry & Biological Molecules – 8 questions
Q1: Water has a high specific heat capacity, which means it takes a lot of energy to
change its temperature. Which of the following is a biological benefit of this property?
A. It causes water to freeze from the top down, insulating liquid water below.
B. It allows water to act as a universal solvent for polar molecules.
C. It helps organisms maintain a relatively stable internal temperature despite
environmental changes.
D. It enables water molecules to stick to each other through hydrogen bonds (cohesion).
Correct Answer: C
Rationale: The best answer is stabilizing internal temperature because water's ability to
absorb or release large amounts of heat with minimal temperature change acts as a
buffer against thermal fluctuations in organisms and the environment.
Q2: A student is testing substances in the lab and finds that a solution has a pH of 3. Is
this solution acidic, basic, or neutral?
A. Basic
B. Neutral
C. Acidic
D. Neither acidic nor basic
Correct Answer: C
Rationale: This choice is correct because the pH scale runs from 0 to 14, where values
below 7 are acidic, 7 is neutral, and values above 7 are basic (alkaline).
Q3: Sodium chloride (NaCl) is a common table salt. Which type of chemical bond holds
the sodium and chlorine ions together in this compound?
A. Covalent bond
,B. Hydrogen bond
C. Ionic bond
D. Polar covalent bond
Correct Answer: C
Rationale: This aligns with ionic bonding because sodium (a metal) transfers an electron
to chlorine (a nonmetal), resulting in oppositely charged ions that attract each other to
form a stable crystal lattice.
Q4: Carbohydrates are a major source of energy for the body. Which of the following
best describes the monomer (building block) of carbohydrates like starch and glycogen?
A. Fatty acid
B. Amino acid
C. Monosaccharide (simple sugar)
D. Nucleotide
Correct Answer: C
Rationale: The best answer is monosaccharide because complex carbohydrates
(polysaccharides) are long chains of linked sugar units (monosaccharides) like glucose.
Q5: A dietitian advises a patient to limit their intake of saturated fats found in animal
products. What is the chemical difference between saturated and unsaturated fats?
A. Saturated fats contain double bonds between carbons; unsaturated fats have single
bonds.
B. Saturated fats are liquids at room temperature; unsaturated fats are solids.
C. Saturated fats have the maximum number of hydrogen atoms bonded to carbons;
unsaturated fats have fewer hydrogens due to double bonds.
D. Saturated fats are composed primarily of unsaturated fatty acids.
Correct Answer: C
Rationale: This choice is correct because "saturated" means the carbon chains are
holding as many hydrogen atoms as possible (all single bonds), which typically makes
them solid at room temperature, unlike unsaturated fats which have kinks from double
bonds.
Q6: Proteins have a complex structure that determines their function. Which level of
protein structure describes the linear sequence of amino acids linked by peptide bonds?
A. Primary structure
B. Secondary structure
C. Tertiary structure
D. Quaternary structure
Correct Answer: A
Rationale: The best answer is primary structure because it refers specifically to the
unique order of amino acids in a polypeptide chain, akin to letters spelling a word.
, Q7: Adenosine triphosphate (ATP) is often called the "energy currency" of the cell.
Which type of biological molecule does ATP belong to?
A. Protein
B. Lipid
C. Nucleic acid
D. Carbohydrate
Correct Answer: C
Rationale: This aligns with molecular classification because ATP is a nucleotide
composed of a nitrogenous base (adenine), a sugar (ribose), and three phosphate
groups, making it part of the nucleic acid family.
Q8: Water molecules exhibit cohesion, meaning they tend to stick to each other. Which
property of water is directly responsible for this behavior?
A. Polarity of the water molecule
B. High specific heat
C. Lower density as a solid than liquid
D. High surface tension
Correct Answer: A
Rationale: This choice is correct because cohesion is caused by the polar nature of
water molecules; the slightly positive hydrogen of one molecule is attracted to the
slightly negative oxygen of another, creating hydrogen bonds between them.
Cell Structure, Function & Membrane Transport – 10 questions
Q9: While observing a sample under a microscope, a student identifies a cell that has a
nucleus and membrane-bound organelles but lacks a cell wall. This cell is most likely
from a(n):
A. Plant
B. Fungus
C. Bacterium
D. Animal
Correct Answer: D
Rationale: The best answer is animal because eukaryotic animal cells possess a
nucleus and organelles but do not have the rigid cell wall found in plants, fungi, and
most bacteria.
Q10: Which cellular organelle is responsible for producing ATP through cellular
respiration?
A. Ribosome
B. Smooth endoplasmic reticulum
C. Mitochondria
