state a prediction about the expected ratio of normal to polka-dot gametophytes?

[e:pippie:e]

All of the spores used for this study were produced by a heterozygotic sporophyte. We will designate two alleles at the gene for the polka-dot trait, one dominant (D) and one recessive (d). One of these alleles will code for the polka-dot phenotype and the other will code for green phenotype.

For this trait, we are hypothesizing that the phenotypes are controlled by two segregating alleles at a single gene. Based on this hypothesis, state a prediction about the expected ratio of normal to polka-dot gametophytes.

I'm not sure how to answer this. Please help! Thanks!

 

[emucompboy]

Whoa. I got surprised! Your teacher deserves a pat on the back for asking an awesomely good question.

The key words here are sporophyte and gametophyte. That tells me we're dealing with plants (or something like them) with alternation of generations.
In plants, the sporophyte is diploid; the gametophyte is haploid.
So if your sporophyte is known to be heterozygous, then the gametophytes will have a
1:1 [answer]
ratio for this trait, assuming that the haploid gametophyte expresses this trait at all.

Bein' haploid, that means that they get only one allele. There's no second allele for this gene locus to mask a recessive with a dominant, because there's only one (haploid) set of chromosomes.