For 10 points, name this taxonomic group of seed-bearing plants that, unlike angiosperms, do not produce flowers.
One phylum in this clade consists of a single extant species with X and Y sex chromosomes determining its microsporangiate and megasporangiate forms. Another phylum in this clade produces male gametophytes in pollen strobili, and its ovules form on modified branches that form a seed (*) cone. Those two phyla contain Gingko biloba and conifers, respectively. This clade takes its name from the Greek for "naked seed." For 10 points, name this taxonomic group of seed-bearing plants that, unlike angiosperms, do not produce flowers.
One phylum in this clade consists of a single extant species with X and Y sex chromosomes determining its microsporangiate and megasporangiate forms.
{gymnosperms}