Short answers, pulled from the story.
Gymnosperm comes from Ancient Greek: gymnos, meaning naked, and spérma, meaning seed. The name refers to the fact that gymnosperm seeds develop without an enclosing ovary, resting exposed on the surface of scales or leaves.
Early characteristics of seed plants appear in fossil progymnosperms from the late Devonian period, around 383 million years ago. More recent phylogenetic evidence indicates gymnosperms diverged from the ancestors of flowering plants during the Early Carboniferous period.
The four living gymnosperm groups are conifers, cycads, gnetophytes, and Ginkgo. Conifers are the largest group, with 600-630 species; cycads number approximately 338 species; gnetophytes include 95-100 species; and Ginkgo biloba is a single surviving species.
Gymnosperm seeds develop on the surface of scales or leaves rather than enclosed within an ovary. Cycads and Ginkgo produce flagellated sperm that swim to the egg, while conifers and gnetophytes deliver non-flagellated sperm via a pollen tube.
Picea abies, the Norway spruce, was the first gymnosperm to have its genome published in sequenced form, in 2013.
Gymnosperms including pine, fir, spruce, and cedar are used for lumber, paper production, and resin. They also contribute to soap, varnish, nail polish, food products, gum, and perfumes.