MCQ Collection
MDCAT Biology MCQs
Practice MDCAT Biology questions with answers and explanations.
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Correct Answer: C. Substrate binding causes a conformational adjustment in the active site
Explanation:
The active site is flexible rather than perfectly rigid.
Binding aligns catalytic groups and stabilizes the transition state.
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Correct Answer: C. Individuals vary in heritable traits and reproductive success
Explanation:
Natural selection requires heritable variation and unequal reproduction.
Favorable traits can increase over generations.
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Correct Answer: D. Receptor → sensory neuron → relay neuron → motor neuron → effector
Explanation:
A reflex begins with receptor stimulation and sensory input.
Motor output then activates an effector.
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Correct Answer: D. They contain more energy-rich C-H bonds
Explanation:
Fats are more reduced than carbohydrates.
Their oxidation supplies more high-energy electrons to respiration.
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Correct Answer: D. It supplies H and OH to split a bond
Explanation:
Hydrolysis uses a water molecule to break a covalent bond.
The products receive hydrogen and hydroxyl groups.
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Correct Answer: A. They contain more energy-rich C-H bonds
Explanation:
Fats are more reduced than carbohydrates.
Their oxidation supplies more high-energy electrons to respiration.
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Correct Answer: A. A protein with attached carbohydrate groups
Explanation:
Glycoproteins contain covalently attached carbohydrate chains.
They function in receptors, recognition and cell adhesion.
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Correct Answer: B. Krebs cycle
Explanation:
Acetyl-CoA and other intermediates enter the Krebs cycle.
Different food molecules therefore converge on common respiratory pathways.
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Correct Answer: B. A protein with attached carbohydrate groups
Explanation:
Glycoproteins contain covalently attached carbohydrate chains.
They function in receptors, recognition and cell adhesion.
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Correct Answer: C. Krebs cycle
Explanation:
Acetyl-CoA and other intermediates enter the Krebs cycle.
Different food molecules therefore converge on common respiratory pathways.
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Correct Answer: C. A protein with attached carbohydrate groups
Explanation:
Glycoproteins contain covalently attached carbohydrate chains.
They function in receptors, recognition and cell adhesion.
Choose an option to check your answer.
Correct Answer: D. Krebs cycle
Explanation:
Acetyl-CoA and other intermediates enter the Krebs cycle.
Different food molecules therefore converge on common respiratory pathways.
