MCQ Collection
MDCAT 2026 MCQs
Practice MDCAT 2026 questions with answers and explanations.
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Correct Answer: A. A heritable change in genetic material
Explanation:
Mutations may alter one base, a gene, or chromosome structure.
They create genetic variation.
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Correct Answer: B. An allele whose effect is masked in a heterozygote
Explanation:
A recessive phenotype usually appears when no dominant allele is present.
The allele can still be transmitted by carriers.
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Correct Answer: B. A heritable change in genetic material
Explanation:
Mutations may alter one base, a gene, or chromosome structure.
They create genetic variation.
Choose an option to check your answer.
Correct Answer: C. An allele whose effect is masked in a heterozygote
Explanation:
A recessive phenotype usually appears when no dominant allele is present.
The allele can still be transmitted by carriers.
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Correct Answer: C. A change affecting a single nucleotide pair
Explanation:
Point mutations include substitutions and small insertions or deletions.
Their effects vary with location and type.
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Correct Answer: D. Having two identical alleles at a locus
Explanation:
A homozygous individual may be dominant or recessive.
Both homologous chromosomes carry the same allele.
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Correct Answer: D. A change affecting a single nucleotide pair
Explanation:
Point mutations include substitutions and small insertions or deletions.
Their effects vary with location and type.
Choose an option to check your answer.
Correct Answer: A. Having two identical alleles at a locus
Explanation:
A homozygous individual may be dominant or recessive.
Both homologous chromosomes carry the same allele.
Choose an option to check your answer.
Correct Answer: A. A change affecting a single nucleotide pair
Explanation:
Point mutations include substitutions and small insertions or deletions.
Their effects vary with location and type.
Choose an option to check your answer.
Correct Answer: B. Having two identical alleles at a locus
Explanation:
A homozygous individual may be dominant or recessive.
Both homologous chromosomes carry the same allele.
Choose an option to check your answer.
Correct Answer: B. A solution containing more dissolved solute than equilibrium normally allows
Explanation:
Supersaturated solutions are metastable.
Crystallization can be triggered by a seed crystal or disturbance.
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Correct Answer: C. Having two different alleles at a locus
Explanation:
A heterozygote carries two allele forms.
Its phenotype depends on their interaction.
