Question

You perform a cross between two pea plants that have the following genotypes: PP Yy Tt and Pp Yy tt. The alleles code for flower color (PP, Pp= purple flowers pp= white flowers) seed color (YY,Yy= yellow seeds, yy= green seeds) and plant height (TT,Tt= tall plant, tt= short plant). What percentage of the offspring will have the genotype Pp YY Tt?

Answer 1

It's not possible to get offspring with the genotype Pp YY Tt from the cross between PP Yy Tt and Pp Yy tt, as the Y gene cannot be homozygous dominant (YY) from the given parent genotypes, so the percentage is 0%.

Step-by-step explanation:

The subject of this question is Biology, specifically Mendelian genetics involving dihybrid crosses. To find the percentage of offspring with the genotype Pp YY Tt from the cross between PP Yy Tt and Pp Yy tt, we need to consider each gene separately because they are inherited independently (Law of Independent Assortment).

First, for the P gene, we can only get Pp offspring because one parent is homozygous PP and the other is heterozygous Pp. For the Y gene, since one parent is Yy and the other is yy, we can only have Yy offspring which means no YY offspring are possible from this cross. For the T gene, we have one parent Tt and the other tt, so we can get Tt or tt offspring.

Since we are looking for the genotype Pp YY Tt and the genotypes at the Y locus from the parental cross only result in Yy, it's not possible to get YY offspring from this cross combination. Therefore, the percentage of offspring that will be Pp YY Tt is 0%.