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."
Last updated
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.
Practise Inheritance
1,238 free Inheritance MCQs from Biology, each with the correct answer and an explanation. Unlimited attempts, no account needed.
Exams that ask Biology questions like this
Biology is on 6 papers prepared for on TestUstad, and all of them draw the same bank, so this question is worth knowing for every one of them.
Related questions
A carrier of haemophilia is typically
A chromosome have two genes X and Y. Gene Y influences the phenotypic effect of gene X.Based on the influential phenotypic effect, the gene Y is:
A colour blind man marries a woman with normal vision whose father was colour blind. What proportion of their daughters will be colour blind?
A couple has blood group A and B, respectively. The blood group of their son is AB and the daughter has blood group O.The parents and the children have four different genotypes for the same trait because the:
A gene which affects two or more unrelated characteristics is called