MCQ Collection
MDCAT 2026 MCQs
Practice MDCAT 2026 questions with answers and explanations.
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Correct Answer: A. RNA carrying amino acids to the ribosome
Explanation:
TRNA has an anticodon and an amino-acid attachment site.
It matches amino acids to mRNA codons.
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Correct Answer: A. AUG
Explanation:
AUG codes for methionine and usually serves as the start codon.
It establishes the reading frame.
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Correct Answer: A. Observable characteristics of an organism
Explanation:
Phenotype includes structural, biochemical, and behavioral traits.
It is influenced by genes and environment.
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Correct Answer: B. RNA carrying amino acids to the ribosome
Explanation:
TRNA has an anticodon and an amino-acid attachment site.
It matches amino acids to mRNA codons.
Choose an option to check your answer.
Correct Answer: B. AUG
Explanation:
AUG codes for methionine and usually serves as the start codon.
It establishes the reading frame.
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Correct Answer: B. An allele expressed in a heterozygote
Explanation:
Dominance describes phenotype in a heterozygote.
It does not imply greater frequency or fitness.
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Correct Answer: C. RNA carrying amino acids to the ribosome
Explanation:
TRNA has an anticodon and an amino-acid attachment site.
It matches amino acids to mRNA codons.
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Correct Answer: C. UAA, UAG, and UGA
Explanation:
Stop codons do not encode amino acids.
They recruit release factors to end translation.
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Correct Answer: C. An allele expressed in a heterozygote
Explanation:
Dominance describes phenotype in a heterozygote.
It does not imply greater frequency or fitness.
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Correct Answer: D. RNA forming structural and catalytic parts of ribosomes
Explanation:
RRNA combines with proteins to form ribosomal subunits.
It helps catalyze peptide-bond formation.
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Correct Answer: D. UAA, UAG, and UGA
Explanation:
Stop codons do not encode amino acids.
They recruit release factors to end translation.
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Correct Answer: D. An allele expressed in a heterozygote
Explanation:
Dominance describes phenotype in a heterozygote.
It does not imply greater frequency or fitness.
