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Spermatophytes
- Gymnosperms, also called Acrogymnospermae (1), are a group of seed-bearing plants (spermatophytes) with ovules on the edge or blade of an open sporophyll or ovuliferous scale (Fig. 1). 7eir closest extant relatives are the angiosperms, which have ovules enclosed in a carpel.
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Oct 14, 2024 · gymnosperm, any vascular plant that reproduces by means of an exposed seed, or ovule—unlike angiosperms, or flowering plants, whose seeds are enclosed by mature ovaries, or fruits. The seeds of many gymnosperms (literally, “naked seeds”) are borne in cones and are not visible until maturity.
The gymnosperms (/ ˈdʒɪmnəˌspɜːrmz, - noʊ -/ ⓘ JIM-nə-spurmz, -noh-; lit. 'revealed seeds') are a group of seed-producing plants that include conifers, cycads, Ginkgo, and gnetophytes, forming the clade Gymnospermae. The term gymnosperm comes from the composite word in Greek: γυμνόσπερμος (γυμνός, gymnos, 'naked ...
Gymnosperm seeds are usually formed in unisexual cones, known as strobili, and the plants lack fruits and flowers. Both groups use pollen to facilitate fertilization, though angiosperms have an incredible diversity of pollination strategies that are not found among the gymnosperms.
- Melissa Petruzzello
Lower vascular plants, such as club mosses and ferns, are mostly homosporous (produce only one type of spore). In contrast, all seed plants, or spermatophytes, are heterosporous, forming two types of spores: megaspores (female) and microspores (male).
Gymnosperms are heterosporous, producing microspores that develop into pollen grains and megaspores that are retained in an ovule. After fertilization (joining of the micro- and mega- spore), the resulting embryo, along with other cells comprising the ovule, develops into a seed.
Jul 31, 2022 · The life cycle of a gymnosperm involves alternation of generations, with a dominant sporophyte in which the female gametophyte resides, and reduced gametophytes. All gymnosperms are heterosporous. The male and female reproductive organs can form in cones or strobili.
Gymnosperms, also called Acrogymnospermae (1), are a group of seed-bearing plants (spermatophytes) with ovules on the edge or blade of an open sporophyll or ovuliferous scale (Fig. 1). 7eir closest extant relatives are the angiosperms, which have ovules enclosed in a carpel.
