Question

In pea plants, purple flowers (P) are dominant over white flowers (p) and tall stems (T) are dominant over short stems (t). Complete a dihybrid cross for parents with the genotypes: PpTT × ppTt and answer the following in complete sentences.

Describe how you would set up a Punnett square for this cross.
List the likelihood of each possible offspring genotype.
List the likelihood of each possible offspring phenotype.

Answer 1

PP=0.25 (ie 1/4)
Pp=0.5
pp=0.25

As P is dominant, PP and Pp will yield purple in the phenotype, so 0.25+0.5 chance of that, and only pp (0.25) will yield white.

And apply the same logic to that.

I guess you'd draw the crosses separately as they are mutually exclusive.