The punnet square that CORRECTLY represents a dihybrid cross between two heterozygous RrYy × RrYy pea plants with round yellow seeds is:
Correct answer: A. Option A
- A. Option A
- B. Option B
- C. Option C
- D. Option D
Explanation
Phenotypes seed shape & colour follow the classic 9:3:3:1 ratio:9 round-yellow (dominant for both)3 round-green (dominant shape, recessive colour)3 wrinkled-yellow (recessive shape, dominant colour)1 wrinkled-green (recessive for both)So A is the correct option.The rest of the options are incorrect because they show gametes in the wrong order, which results in a phenotypic ratio that is not 9:3:3:1."
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About Mendel's Laws of Inheritance
Mendelian inheritance explains how alleles separate into gametes and assort during reproduction, producing predictable genotype and phenotype ratios. Questions cover dominance, recessiveness, homozygous and heterozygous conditions, the laws of segregation and independent assortment, monohybrid and dihybrid crosses, test crosses and the limits caused by linked genes.
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