MCQ Collection
MDCAT 2026 MCQs
Practice MDCAT 2026 questions with answers and explanations.
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Correct Answer: A. sp3
Explanation:
Four equivalent bonding directions correspond to sp3 hybridization.
The ideal geometry is tetrahedral.
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Correct Answer: D. Cytosine and thymine
Explanation:
DNA pyrimidines have single-ring structures.
They are cytosine and thymine.
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Correct Answer: D. Each new molecule contains one parental and one newly synthesized strand
Explanation:
The parental strands separate and serve as templates.
Each completed double helix preserves one original strand.
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Correct Answer: A. A pairs with T, and G pairs with C
Explanation:
Hydrogen bonding produces specific pairing.
This complementarity supports accurate replication.
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Correct Answer: A. Each new molecule contains one parental and one newly synthesized strand
Explanation:
The parental strands separate and serve as templates.
Each completed double helix preserves one original strand.
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Correct Answer: B. A pairs with T, and G pairs with C
Explanation:
Hydrogen bonding produces specific pairing.
This complementarity supports accurate replication.
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Correct Answer: B. Each new molecule contains one parental and one newly synthesized strand
Explanation:
The parental strands separate and serve as templates.
Each completed double helix preserves one original strand.
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Correct Answer: C. A pairs with T, and G pairs with C
Explanation:
Hydrogen bonding produces specific pairing.
This complementarity supports accurate replication.
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Correct Answer: C. Helicase
Explanation:
Helicase breaks hydrogen bonds between base pairs.
It opens the replication fork.
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Correct Answer: D. Hydrogen bond
Explanation:
Hydrogen bonds join bases across the two DNA strands.
Covalent phosphodiester bonds form each strand's backbone.
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Correct Answer: D. Helicase
Explanation:
Helicase breaks hydrogen bonds between base pairs.
It opens the replication fork.
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Correct Answer: A. Nucleotide
Explanation:
DNA is a polymer made of nucleotides.
Each nucleotide contains a sugar, phosphate, and nitrogenous base.
