Q14 from this weekend's quiz...

I've had a couple questions about Q14 from this weekend's quiz:  If a heterozygous purple-flowered pea plant is crossed with a homozygous white-flowered plant, what proportion of offspring will be white-flowered?
First, even if you didn't know which trait was dominant (purple or white flowers), you can FIGURE IT OUT just by reading the question.  A heterozygous purple plant MUST have both alleles (Pp), so purple must be the dominant trait.  This works, because the white plant is homozygous (pp).
So we have our parent genotypes:  Pp   x    pp
Possible gametes?  The Pp plant gives rise to two possible gametes:  p and P
The pp plant can only have p gametes.
Your punnet square will look like this...then you determine the possible phenotypes from this.

 Hope this helps...holler back if you have more questions.