WGU D849 General Biology I – 100
OA Practice Questions with Answers
& Rationales
Below are 100 original practice questions covering cells, genetics, photosynthesis,
respiration, evolution, and ecology for the WGU D849 Objective Assessment.
SECTION 1: CELL STRUCTURE & FUNCTION (Questions 1–20)
Question 1
Which of the following is NOT part of the cell theory?
• A) All living things are composed of one or more cells
• B) All new cells are created by preexisting cells dividing
• C) All cells contain a nucleus
• D) The cell is the most basic unit of structure and function in all living
organisms
Answer: C
Rationale: Cell theory states that all living things are composed of cells, all new cells
come from preexisting cells, and the cell is the basic unit of life. Prokaryotic cells lack a
nucleus, so not all cells contain a nucleus .
Question 2
Which of the following is a key difference between prokaryotic and eukaryotic cells?
, • A) Prokaryotic cells have a nucleus; eukaryotic cells do not
• B) Prokaryotic cells lack membrane-bound organelles; eukaryotic cells
have them
• C) Prokaryotic cells are larger than eukaryotic cells
• D) Prokaryotic cells have mitochondria; eukaryotic cells do not
Answer: B
Rationale: Prokaryotic cells lack membrane-bound organelles and a true nucleus.
Eukaryotic cells have a defined nucleus and membrane-bound organelles .
Question 3
Which organelle is responsible for producing ATP through cellular respiration?
• A) Ribosome
• B) Nucleus
• C) Mitochondria
• D) Golgi apparatus
Answer: C
Rationale: Mitochondria are the site of cellular respiration and ATP production, often
called the "powerhouse" of the cell .
Question 4
Which organelle is the site of protein synthesis?
• A) Ribosome
, • B) Mitochondria
• C) Chloroplast
• D) Lysosome
Answer: A
Rationale: Ribosomes synthesize proteins by translating mRNA. They can be free-
floating or attached to the rough endoplasmic reticulum .
Question 5
Which of the following is found in plant cells but NOT in animal cells?
• A) Mitochondria
• B) Ribosomes
• C) Chloroplasts
• D) Cell membrane
Answer: C
Rationale: Chloroplasts are the site of photosynthesis and are found in plant cells and
some algae, but not in animal cells .
Question 6
What is the function of the cell membrane?
• A) Producing ATP
• B) Synthesizing proteins
• C) Regulating movement of substances in and out of the cell
, • D) Storing genetic material
Answer: C
Rationale: The cell membrane is selectively permeable and regulates what enters and
exits the cell .
Question 7
Which of the following correctly describes the phospholipid bilayer?
• A) Hydrophilic tails face outward; hydrophobic heads face inward
• B) Hydrophilic heads face outward; hydrophobic tails face inward
• C) Both heads and tails are hydrophobic
• D) Both heads and tails are hydrophilic
Answer: B
Rationale: The phospholipid bilayer has hydrophilic (water-loving) heads facing
outward toward water and hydrophobic (water-fearing) tails facing inward, away from
water .
Question 8
Which organelle modifies, sorts, and packages proteins?
• A) Nucleus
• B) Ribosome
• C) Golgi apparatus
• D) Mitochondria
OA Practice Questions with Answers
& Rationales
Below are 100 original practice questions covering cells, genetics, photosynthesis,
respiration, evolution, and ecology for the WGU D849 Objective Assessment.
SECTION 1: CELL STRUCTURE & FUNCTION (Questions 1–20)
Question 1
Which of the following is NOT part of the cell theory?
• A) All living things are composed of one or more cells
• B) All new cells are created by preexisting cells dividing
• C) All cells contain a nucleus
• D) The cell is the most basic unit of structure and function in all living
organisms
Answer: C
Rationale: Cell theory states that all living things are composed of cells, all new cells
come from preexisting cells, and the cell is the basic unit of life. Prokaryotic cells lack a
nucleus, so not all cells contain a nucleus .
Question 2
Which of the following is a key difference between prokaryotic and eukaryotic cells?
, • A) Prokaryotic cells have a nucleus; eukaryotic cells do not
• B) Prokaryotic cells lack membrane-bound organelles; eukaryotic cells
have them
• C) Prokaryotic cells are larger than eukaryotic cells
• D) Prokaryotic cells have mitochondria; eukaryotic cells do not
Answer: B
Rationale: Prokaryotic cells lack membrane-bound organelles and a true nucleus.
Eukaryotic cells have a defined nucleus and membrane-bound organelles .
Question 3
Which organelle is responsible for producing ATP through cellular respiration?
• A) Ribosome
• B) Nucleus
• C) Mitochondria
• D) Golgi apparatus
Answer: C
Rationale: Mitochondria are the site of cellular respiration and ATP production, often
called the "powerhouse" of the cell .
Question 4
Which organelle is the site of protein synthesis?
• A) Ribosome
, • B) Mitochondria
• C) Chloroplast
• D) Lysosome
Answer: A
Rationale: Ribosomes synthesize proteins by translating mRNA. They can be free-
floating or attached to the rough endoplasmic reticulum .
Question 5
Which of the following is found in plant cells but NOT in animal cells?
• A) Mitochondria
• B) Ribosomes
• C) Chloroplasts
• D) Cell membrane
Answer: C
Rationale: Chloroplasts are the site of photosynthesis and are found in plant cells and
some algae, but not in animal cells .
Question 6
What is the function of the cell membrane?
• A) Producing ATP
• B) Synthesizing proteins
• C) Regulating movement of substances in and out of the cell
, • D) Storing genetic material
Answer: C
Rationale: The cell membrane is selectively permeable and regulates what enters and
exits the cell .
Question 7
Which of the following correctly describes the phospholipid bilayer?
• A) Hydrophilic tails face outward; hydrophobic heads face inward
• B) Hydrophilic heads face outward; hydrophobic tails face inward
• C) Both heads and tails are hydrophobic
• D) Both heads and tails are hydrophilic
Answer: B
Rationale: The phospholipid bilayer has hydrophilic (water-loving) heads facing
outward toward water and hydrophobic (water-fearing) tails facing inward, away from
water .
Question 8
Which organelle modifies, sorts, and packages proteins?
• A) Nucleus
• B) Ribosome
• C) Golgi apparatus
• D) Mitochondria
