Gymnosperms are seed-producing plants with six phyla: Cycadophyta, Ginkgophyta, Gnetophyta, Pinophyta (Coniferophyta), Pteridospermales and Cordaitales.
Ginkgophyta is a phylum with a single living species-Ginkgo biloba.
Pteridospermales and Cordaitales phyla are now extinct.
Pinophyta (Coniferophyta) is the largest phyla of the Gymnosperms which includes pines, cypresses and relatives.
The gymnosperms phylum which includes only one living species is:
Ginkgophyta only one type survives Ginkgo biloba.Further explanation
Plants are divided into two, namely vascular plants and vascular plants. Examples of vascular plants are moss, whereas vascular plants consist of seedless plants, which are nails and seed plants. While seed plants themselves are divided into closed seed plants (angiosperms) and open seed plants (gymnosperms).
Seed plants are grouped into two subdivisions, namely open seed plants (Gymnosperms) and closed seed plants (Angiosperms). Gymnosperms are plants that have open seeds. They are a group of seed plants whose seeds are not protected in ovaries.
Gymnosperms consist of several divisions, both extinct and extant, which include 3 divisions that have become extinct and 4 divisions that still survive.
The first extinct Gymnosperms plants include the following which encompasses 3 extinct divisions:
- Pteridospermophyta, extinct but considered to be the ancestor of Angiospermae.
The second is the Gymnosperms plant that still exists today, which includes four Gymnosperms divisions, including the following:
1) Coniferophyta or can be called Pinophyta
It is a conifers.
With only 3 members of the genus: Gnetum, Welwitschia, and Ephedra.
Cycadophyta is divided into two families, namely Cycadaceae and Zamiaceae.
Only one type remains: Ginkgo biloba
phylum of the gymnosperms
Class: High School
Keyword: Phylum of the gymnosperms.
Conifers are the only living specie of gymnosperms and are cone bearing seed plants which are needle like and evergreen. Conifers produce pinecones and are common in the cold and boreal region. They are good timbers trees and are used for ornamental purposes. Conifers are the most important and diverse class of gymnosperms with about 588 living species. Examples are pines, cypresses, etc.
genetic variation can be caused by mutation (which can create entirely new alleles in a population), random mating, random fertilization, and recombination between homologous chromosomes during meiosis (which reshuffles alleles within an organism's offspring).