O-LevelBiologyGenetics & Variation5090/11 · Oct/Nov 2021 · Q381 Mark

One gene has two codominant alleles, Aᴱ and Aᴳ, and one recessive allele, Aᴴ. How many different genotypes and phenotypes are possible?

Agenotypes 3, phenotypes 3

Bgenotypes 4, phenotypes 6

Cgenotypes 6, phenotypes 4

Dgenotypes 6, phenotypes 6

✓ Correct answer

C: genotypes 6, phenotypes 4

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Topic: Genetics & Variation, O-Level Biology (syllabus 5090). Multiple choice, 1 mark.
Source: O-Level Biology, Oct/Nov 2021 Paper 1 Variant 1, question 38.

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