gymnospermat

Gymnospermat, commonly known as gymnosperms, are a group of seed plants whose seeds are not enclosed within an ovary. The living gymnosperms are divided into four clades: Coniferophyta (conifers), Cycadophyta (cycads), Ginkgophyta (Ginkgo), and Gnetophyta (gnetophytes).

Seeds develop on exposed ovules borne on cone scales or other reproductive structures rather than inside a fruit. Fertilization is typically accomplished by wind-dispersed pollen; once fertilized, the ovule develops into a seed that can be dispersed to germinate into a new sporophyte.

Gymnosmat display a predominantly sporophyte life cycle. The gametophyte generation is reduced and nutritionally dependent on the sporophyte: male gametophytes (pollen) deliver sperm, and female gametophytes develop within the ovule to receive the pollen for fertilization.

Ecology and evolution: Gymnospermat are widespread in temperate and boreal regions, with conifers forming extensive forests in the Northern Hemisphere. They arose in the Paleozoic era and diversified through the Mesozoic, often described as the first dominant seed plants with seeds adapted to dry conditions.

Diversity and conservation: There are roughly 1000 to 1100 living species, distributed in four divisions. Gymnospermat face threats from habitat loss, climate change, and pests; many species are protected, and seed banks and habitat restoration are used in conservation efforts.