College

Assume that white color is dominant over yellow color in squash. If pollen from the anthers of a heterozygous white-fruited plant is placed on the pistil of a yellow-fruited plant, show using ratios the genotypes and phenotypes you would expect the seeds from this cross to produce.

1. Genotypes: 1/2 Ww, 1/2 Ww (1:1 ratio)
Phenotypes: All white (1:0 ratio)

2. Genotypes: 1/2 Ww, 1/2 ww (1:1 ratio)
Phenotypes: 1/2 white, 1/2 yellow (1:1 ratio)

3. Genotypes: 3/4 Ww, 1/4 ww (3:1 ratio)
Phenotypes: 3/4 white, 1/4 yellow (3:1 ratio)

4. Genotypes: 1/2 ww, 1/2 ww (1:1 ratio)
Phenotypes: 1/2 white, 1/2 yellow (1:1 ratio)

Answer :

Answer:

2. Genotypes 1/2 Ww 1/2 ww 1:1 ratio | Phenotypes 1/2 white 1/2 yellow 1:1 ratio

Explanation:

This question involves a single gene coding for fruit color in squash. The allele for white color (W) is dominant over the allele for yellow color (w).

If a heterozygous white-fruited plant (Ww) is crossed with a yellow-fruited plant (ww), the following gamete combinations will be produced by each parent:

Ww- W and w

ww- w and w

Using these gametes in a punnet square (see attached image), offsprings with genotypes: Ww and ww will be produced in the ratio 1:1

(1/2) Ww will be phenotypically white-fruited

(1/2) ww will be phenotypically yellow-fruited

Hence, the seed offsprings of this cross will possess:

Genotypes 1/2 Ww, 1/2 ww in 1:1 ratio

Phenotypes 1/2 white, 1/2 yellow in 1:1 ratio

The cross between a heterozygous white-fruited squash plant and a yellow-fruited plant results in genotypes 1/2 Ww and 1/2 ww, and phenotypes 1/2 white and 1/2 yellow in a 1:1 ratio. The correct option is 2.

To address this question, we need to analyze the cross between a heterozygous white-fruited squash plant (Ww) and a yellow-fruited squash plant (ww). Here, W (white) is dominant over w (yellow).

Using a Punnett square, we can determine the possible genotypes and phenotypes of the offspring:

Genotypes and Phenotypes:

  • Genotypes: 1/2 Ww, 1/2 ww (1:1 ratio)
  • Phenotypes: 1/2 white, 1/2 yellow (1:1 ratio)

The correct answer is option 2 as it accurately represents the expected outcomes of this cross.