Question

Lupe grows pea plants in her garden. The pea plants have flowers that can be either purple or white, with purple color being dominant to white color. The peas produced by Lupe's pea plants can also be either round or wrinkled, with round peas being dominant to wrinkled peas. Lupe crosses two pea plants that are heterozygous for both traits. If a gamete from this cross receives a dominant allele for flower color, how does this influence the probability of the gamete receiving a dominant allele for pea shape? (Assume that the genes for flower color and pea shape follow the law of independent assortment.)

Answer 1

It has no effect on the probability of the gamete receiving a dominant allele for pea shape.

Hope that helps

Answer 2

Probability of the gamete receiving a dominant allele for pea shape if it has dominant allele for flower color is

`(9)/(16)`

Explanation-

Let "P" represents purple color and "p" represents white color.

While "R" represents round pea seed while "r" represents wrinkled pea seed

Genotype of parent with both heterozygous trait - PpRr

PR Pr pR pr

PR PPRR PPRr PpRR PpRr

Pr PPRr PPrr PpRr Pprr

pR PpRR PpRr ppRR ppRr

pr PpRr Pprr ppRr pprr

Possible genotypes are –

PPRR-1

PPRr-2

PpRR- 1

PpRr-4

PPrr-1

Pprr-2

PpRR-1

ppRR-1

ppRr-2

pprr-1

Out of 16 possible genotype of offspring , 12 have dominant allele for flower color i.e "P"

Among these 12 pea plants, 9 have dominant allele for flower shape i.e "R"

Thus , probability of the gamete receiving a dominant allele for pea shape if it has dominant allele for flower color is

`(9)/(16)`