Final answer:
The odds of getting an offspring with Yy genotype when both parents are heterozygous (Yy) is 1:2, as the Yy combination occurs twice in the possible four combinations from a Punnett square cross.
Step-by-step explanation:
The odds of getting an offspring with Yy as a genotype, when both parents are heterozygous (Yy), can be determined using a Punnett square. By crossing Yy x Yy, we find that there are four possible combinations: YY, Yy, yY, and yy. Since Yy and yY are essentially the same genotype (heterozygous), they are grouped together. This results in three genotypic outcomes, with the Yy combination occurring twice:
- 1 YY
- 2 Yy (considering Yy and yY as similar)
- 1 yy
Therefore, the genotype ratio is 1:2:1, with two out of four possible combinations being heterozygous. This gives us the odds of 2 out of 4, or 1:2.