WGU C190 INTRO TO BIOLOGY
ADVANCED OA PREP QUESTIONS AND
ANSWERS
1. Which of the following best describes the role of a control group in a scientific experiment?
A. To represent the group that receives the treatment or intervention
B. To ensure that the hypothesis is proven correct by the end of the study
C. To allow the researcher to change multiple variables at once
D. To serve as a standard for comparison to see the effect of the independent variable
Answer: D
Conceptual Explanation: A control group is essential in experiments to establish a
baseline. By keeping all variables the same except for the one being tested, researchers can
determine if the independent variable caused the observed effect.
2. In a water molecule, the oxygen atom has a slight negative charge while the hydrogen
atoms have a slight positive charge. This property is known as:
A. Nonpolar covalence
B. Ionic bonding
,C. Polarity
D. Hydrophobicity
Answer: C
Conceptual Explanation: Polarity occurs when there is an uneven distribution of electron
density, leading to partial charges. This allows water to form hydrogen bonds and act as a
universal solvent.
3. Which macromolecule is primarily responsible for the long-term storage of energy and the
structure of cell membranes?
A. Lipids
B. Proteins
C. Nucleic Acids
D. Carbohydrates
Answer: A
Conceptual Explanation: Lipids, specifically fats and oils, store long-term energy.
Phospholipids are the primary components of the cell membrane’s bilayer.
4. An enzyme functions by lowering the:
A. Gibbs free energy of the reaction
B. Concentration of the substrate
C. Total heat released by the reaction
, D. Activation energy required for the reaction
Answer: D
Conceptual Explanation: Enzymes are biological catalysts that speed up reactions by
lowering the activation energy barrier, allowing the reaction to proceed faster at
physiological temperatures.
5. Which cellular organelle is responsible for the synthesis of ATP through aerobic
respiration?
A. Golgi apparatus
B. Mitochondria
C. Ribosome
D. Lysosome
Answer: B
Conceptual Explanation: Mitochondria are known as the powerhouses of the cell because
they produce ATP, the main energy currency, through the process of cellular respiration.
6. What is the primary structural difference between prokaryotic and eukaryotic cells?
A. Prokaryotes contain a nucleus, while eukaryotes do not
B. Eukaryotes lack DNA, while prokaryotes use RNA as their primary genetic material
C. Prokaryotes are always multicellular, while eukaryotes are unicellular
D. Eukaryotes contain membrane-bound organelles, while prokaryotes do not
ADVANCED OA PREP QUESTIONS AND
ANSWERS
1. Which of the following best describes the role of a control group in a scientific experiment?
A. To represent the group that receives the treatment or intervention
B. To ensure that the hypothesis is proven correct by the end of the study
C. To allow the researcher to change multiple variables at once
D. To serve as a standard for comparison to see the effect of the independent variable
Answer: D
Conceptual Explanation: A control group is essential in experiments to establish a
baseline. By keeping all variables the same except for the one being tested, researchers can
determine if the independent variable caused the observed effect.
2. In a water molecule, the oxygen atom has a slight negative charge while the hydrogen
atoms have a slight positive charge. This property is known as:
A. Nonpolar covalence
B. Ionic bonding
,C. Polarity
D. Hydrophobicity
Answer: C
Conceptual Explanation: Polarity occurs when there is an uneven distribution of electron
density, leading to partial charges. This allows water to form hydrogen bonds and act as a
universal solvent.
3. Which macromolecule is primarily responsible for the long-term storage of energy and the
structure of cell membranes?
A. Lipids
B. Proteins
C. Nucleic Acids
D. Carbohydrates
Answer: A
Conceptual Explanation: Lipids, specifically fats and oils, store long-term energy.
Phospholipids are the primary components of the cell membrane’s bilayer.
4. An enzyme functions by lowering the:
A. Gibbs free energy of the reaction
B. Concentration of the substrate
C. Total heat released by the reaction
, D. Activation energy required for the reaction
Answer: D
Conceptual Explanation: Enzymes are biological catalysts that speed up reactions by
lowering the activation energy barrier, allowing the reaction to proceed faster at
physiological temperatures.
5. Which cellular organelle is responsible for the synthesis of ATP through aerobic
respiration?
A. Golgi apparatus
B. Mitochondria
C. Ribosome
D. Lysosome
Answer: B
Conceptual Explanation: Mitochondria are known as the powerhouses of the cell because
they produce ATP, the main energy currency, through the process of cellular respiration.
6. What is the primary structural difference between prokaryotic and eukaryotic cells?
A. Prokaryotes contain a nucleus, while eukaryotes do not
B. Eukaryotes lack DNA, while prokaryotes use RNA as their primary genetic material
C. Prokaryotes are always multicellular, while eukaryotes are unicellular
D. Eukaryotes contain membrane-bound organelles, while prokaryotes do not
