WGU C190 INTRO TO BIOLOGY FINAL & PRE-
ASSESSMENT EXAM 2026 | 300 VERIFIED
QUESTIONS & DETAILED RATIONALES |
COMPLETE BIOLOGY OA STUDY GUIDE
• This document contains 200 verified questions with detailed EXPERT RATIONALE
designed to prepare you for the WGU C190 Introduction to Biology OA — use it by
reading each question, selecting your answer, then checking the highlighted correct
option and EXPERT RATIONALE below it.
• Each question follows a consistent format: bolded question, five options (A–E),
bolded correct answer, and a clear EXPERT RATIONALE — ideal for active recall,
timed practice, or final review sessions.
1. What is the basic unit of life?
A. Tissue
B. Organ
C. Nucleus
D. Cell
E. Molecule
Correct Answer: D. Cell
EXPERT RATIONALE: The cell is the smallest structural and functional unit of life. All
living organisms are made of one or more cells, and all cells arise from pre-existing cells,
as stated in cell theory.
2. Which organelle is known as the powerhouse of the cell?
A. Ribosome
B. Nucleus
C. Golgi apparatus
D. Mitochondrion
,E. Endoplasmic reticulum
Correct Answer: D. Mitochondrion
EXPERT RATIONALE: The mitochondrion produces ATP through cellular respiration,
supplying the cell with usable energy. This is why it is commonly called the powerhouse
of the cell.
3. What is the process by which plants make their own food using sunlight?
A. Cellular respiration
B. Fermentation
C. Transpiration
D. Photosynthesis
E. Glycolysis
Correct Answer: D. Photosynthesis
EXPERT RATIONALE: Photosynthesis occurs in the chloroplasts of plant cells, where light
energy is used to convert carbon dioxide and water into glucose and oxygen.
4. Which macromolecule carries genetic information in most organisms?
A. Protein
B. Lipid
C. Carbohydrate
D. DNA
E. RNA
Correct Answer: D. DNA
EXPERT RATIONALE: DNA (deoxyribonucleic acid) is the hereditary material in most
organisms. It stores genetic information that is passed from parent to offspring.
,5. What type of bond holds the two strands of a DNA double helix together?
A. Covalent bonds
B. Ionic bonds
C. Peptide bonds
D. Hydrogen bonds
E. Phosphodiester bonds
Correct Answer: D. Hydrogen bonds
EXPERT RATIONALE: The two strands of DNA are held together by hydrogen bonds
between complementary base pairs — adenine with thymine, and cytosine with guanine.
6. Which of the following best describes a prokaryotic cell?
A. Has a nucleus and membrane-bound organelles
B. Contains chloroplasts and mitochondria
C. Found only in animals
D. Lacks a membrane-bound nucleus
E. Has a cell wall made of cellulose
Correct Answer: D. Lacks a membrane-bound nucleus
EXPERT RATIONALE: Prokaryotic cells, such as bacteria, do not have a membrane-
bound nucleus. Their genetic material floats freely in the cytoplasm in a region called the
nucleoid.
7. Which organelle is responsible for protein synthesis?
A. Lysosome
B. Vacuole
, C. Mitochondrion
D. Ribosome
E. Centrosome
Correct Answer: D. Ribosome
EXPERT RATIONALE: Ribosomes are the sites of protein synthesis. They read mRNA
sequences and assemble amino acids into polypeptide chains through a process called
translation.
8. What is the term for the diffusion of water across a selectively permeable
membrane?
A. Active transport
B. Endocytosis
C. Facilitated diffusion
D. Osmosis
E. Exocytosis
Correct Answer: D. Osmosis
EXPERT RATIONALE: Osmosis is the movement of water molecules from an area of
lower solute concentration to an area of higher solute concentration across a selectively
permeable membrane.
9. Which phase of mitosis involves the alignment of chromosomes at the cell's
equatorial plate?
A. Prophase
B. Anaphase
C. Telophase
D. Metaphase
ASSESSMENT EXAM 2026 | 300 VERIFIED
QUESTIONS & DETAILED RATIONALES |
COMPLETE BIOLOGY OA STUDY GUIDE
• This document contains 200 verified questions with detailed EXPERT RATIONALE
designed to prepare you for the WGU C190 Introduction to Biology OA — use it by
reading each question, selecting your answer, then checking the highlighted correct
option and EXPERT RATIONALE below it.
• Each question follows a consistent format: bolded question, five options (A–E),
bolded correct answer, and a clear EXPERT RATIONALE — ideal for active recall,
timed practice, or final review sessions.
1. What is the basic unit of life?
A. Tissue
B. Organ
C. Nucleus
D. Cell
E. Molecule
Correct Answer: D. Cell
EXPERT RATIONALE: The cell is the smallest structural and functional unit of life. All
living organisms are made of one or more cells, and all cells arise from pre-existing cells,
as stated in cell theory.
2. Which organelle is known as the powerhouse of the cell?
A. Ribosome
B. Nucleus
C. Golgi apparatus
D. Mitochondrion
,E. Endoplasmic reticulum
Correct Answer: D. Mitochondrion
EXPERT RATIONALE: The mitochondrion produces ATP through cellular respiration,
supplying the cell with usable energy. This is why it is commonly called the powerhouse
of the cell.
3. What is the process by which plants make their own food using sunlight?
A. Cellular respiration
B. Fermentation
C. Transpiration
D. Photosynthesis
E. Glycolysis
Correct Answer: D. Photosynthesis
EXPERT RATIONALE: Photosynthesis occurs in the chloroplasts of plant cells, where light
energy is used to convert carbon dioxide and water into glucose and oxygen.
4. Which macromolecule carries genetic information in most organisms?
A. Protein
B. Lipid
C. Carbohydrate
D. DNA
E. RNA
Correct Answer: D. DNA
EXPERT RATIONALE: DNA (deoxyribonucleic acid) is the hereditary material in most
organisms. It stores genetic information that is passed from parent to offspring.
,5. What type of bond holds the two strands of a DNA double helix together?
A. Covalent bonds
B. Ionic bonds
C. Peptide bonds
D. Hydrogen bonds
E. Phosphodiester bonds
Correct Answer: D. Hydrogen bonds
EXPERT RATIONALE: The two strands of DNA are held together by hydrogen bonds
between complementary base pairs — adenine with thymine, and cytosine with guanine.
6. Which of the following best describes a prokaryotic cell?
A. Has a nucleus and membrane-bound organelles
B. Contains chloroplasts and mitochondria
C. Found only in animals
D. Lacks a membrane-bound nucleus
E. Has a cell wall made of cellulose
Correct Answer: D. Lacks a membrane-bound nucleus
EXPERT RATIONALE: Prokaryotic cells, such as bacteria, do not have a membrane-
bound nucleus. Their genetic material floats freely in the cytoplasm in a region called the
nucleoid.
7. Which organelle is responsible for protein synthesis?
A. Lysosome
B. Vacuole
, C. Mitochondrion
D. Ribosome
E. Centrosome
Correct Answer: D. Ribosome
EXPERT RATIONALE: Ribosomes are the sites of protein synthesis. They read mRNA
sequences and assemble amino acids into polypeptide chains through a process called
translation.
8. What is the term for the diffusion of water across a selectively permeable
membrane?
A. Active transport
B. Endocytosis
C. Facilitated diffusion
D. Osmosis
E. Exocytosis
Correct Answer: D. Osmosis
EXPERT RATIONALE: Osmosis is the movement of water molecules from an area of
lower solute concentration to an area of higher solute concentration across a selectively
permeable membrane.
9. Which phase of mitosis involves the alignment of chromosomes at the cell's
equatorial plate?
A. Prophase
B. Anaphase
C. Telophase
D. Metaphase
