MCQ Collection
MDCAT 2026 MCQs
Practice MDCAT 2026 questions with answers and explanations.
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Correct Answer: A. 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: A. 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: B. 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: B. A DNA sequence that contributes to a functional product
Explanation:
Genes may encode proteins or functional RNA molecules.
Their expression is regulated.
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Correct Answer: C. Synthesis of a polypeptide using mRNA codons
Explanation:
Ribosomes read mRNA codons.
TRNAs deliver corresponding amino acids.
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Correct Answer: C. A DNA sequence that contributes to a functional product
Explanation:
Genes may encode proteins or functional RNA molecules.
Their expression is regulated.
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Correct Answer: D. Synthesis of a polypeptide using mRNA codons
Explanation:
Ribosomes read mRNA codons.
TRNAs deliver corresponding amino acids.
Choose an option to check your answer.
Correct Answer: D. A DNA sequence that contributes to a functional product
Explanation:
Genes may encode proteins or functional RNA molecules.
Their expression is regulated.
Choose an option to check your answer.
Correct Answer: A. Synthesis of a polypeptide using mRNA codons
Explanation:
Ribosomes read mRNA codons.
TRNAs deliver corresponding amino acids.
Choose an option to check your answer.
Correct Answer: A. An alternative form of a gene
Explanation:
Alleles occupy the same locus on homologous chromosomes.
They may produce different trait variants.
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Correct Answer: B. A three-nucleotide sequence on mRNA specifying an amino acid or stop signal
Explanation:
The genetic code is read in triplets.
Each codon has a defined meaning.
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Correct Answer: B. An alternative form of a gene
Explanation:
Alleles occupy the same locus on homologous chromosomes.
They may produce different trait variants.
