Answered

In pea plants, the allele for yellow seeds (Y) is dominant, and the allele for green seeds (y) is recessive. Two plants with the following genotypes are crossed:

Yy × Yy

What ratio of yellow seeds to green seeds should you expect in the offspring?

A. 4:0
B. 2:2
C. 3:1
D. 1:3



Answer :

GinnyAnswer
To determine the expected ratio of yellow seeds to green seeds in the offspring of the cross [tex]\( yY \times Yy \)[/tex], we need to consider how the alleles combine. Given that yellow seed color (represented by [tex]\(Y\)[/tex]) is dominant over green seed color (represented by [tex]\(y\)[/tex]), we need to look at the potential combinations of these alleles in the offspring.

1. Identify Potential Genotypes of Offspring:
- Possible combinations of alleles from the cross [tex]\( yY \times Yy \)[/tex] are:
1. YY
2. Yy
3. yY
4. yy

2. Assign Phenotypes:
- Since [tex]\(Y\)[/tex] is dominant:
- YY will produce yellow seeds.
- Yy will produce yellow seeds.
- yY will produce yellow seeds.
- yy will produce green seeds.

3. Count Occurrence of Each Genotype:
- Among the four genotypes, three (YY, Yy, yY) result in yellow seeds and one (yy) results in green seeds.

4. Determine the Ratio:
- From the genotypes, we have:
- 3 combinations result in yellow seeds (YY, Yy, yY).
- 1 combination results in green seeds (yy).

Thus, the ratio of yellow seeds to green seeds in the offspring is:
- 3 yellow seeds : 1 green seed

Hence, the expected ratio of yellow seeds to green seeds is represented by:
Option C: 3:1

Other Questions