Question

A cross between two squash plants that produce yellow squash results in 124 offspring: 93 produce yellow squash and 31 produce green squash. What are the likely genotypes of the plants that were crossed?

Answer 1

Both Yy

Step-by-step explanation:

The genotypes of the plants that were crossed must both have been Yy. A cross between two Yy parents would result in approximately 1/2 Yy offspring, 1/4 YY offspring, and 1/4 yy offspring. Of those offspring, approximately 3/4 (YY and Yy) would express the dominant phenotype. The other 1/4 (yy) would express the recessive phenotype (yy). This is consistent with the results given for the cross.

A cross between two YY parents would result in 100% YY offspring that expressed the dominant phenotype. Likewise, a cross between a YY parent and a yy parent would result in 100% Yy offspring that also expressed the dominant phenotype. A cross between two yy parents would result in 100% yy offspring that expressed the recessive phenotype.

Answer 2

Both Yy

Step-by-step explanation:

1. As given here,

Total offspring are= 124;

that produce yellow squash= 93;

that produce green squash= 31;

2. Let Y for yellow producing squash and y for green squash;

Y is dominant over y.

3. Cross between two yellow squash producing plants

Genotype of parents = Yy and Yy

offspring = YY, Yy, Yy and yy,

as Y is dominant over y, so YY and Yy all produce yellow squash, and yy produce green squash.

4. Their phenotypic ratio is 3:1 , as in question 93: 31