Question

Sometimes, when Mendel crossed two pea plants with each other, he obtained a phenotypic ratio of 3:1 purple-flowered pea plants to white-flowered pea plants. These results are consistent with which set of parents? - heterozygous purple pea plant and homozygous purple pea plant - heterozygous purple pea plant and heterozygous purple pea plant - homozygous purple pea plant and homozygous white pea plant - heterozygous purple pea plant and homozygous white pea plant

Answer 1

Answer:

heterozygous purple pea plant and heterozygous purple pea plant

Explanation:

Suppose the gene controlling flower colour in pea is P. Allele P is dominant over allele p. So, PP and Pp produce purple flowers and pp produces white flowers. If two heterozygous purple pea plants (Pp) are crossed :

Pp X Pp :

    P     p

P  PP  Pp

p  Pp  pp

As evident, the progeny will have genotypic ratio of 1 : 2 : 1 ( PP : Pp : pp ) and phenotypic ratio of 3 : 1 ( Purple : white )

Hence two heterozygous purple pea plants will produce 3:1 ratio of purple to white pea plants.