Gymnosperm | Definition, Description, Plants, Examples, Phylogeny ...
2024年10月14日 · 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.
angiosperm - Encyclopedia Britannica
2024年10月22日 · Angiosperms and gymnosperms both utilize seeds as the primary means of reproduction, and both use pollen to facilitate fertilization. Gymnosperms and angiosperms have a life cycle that involves the alternation of generations, and both have a …
What’s the Difference Between Angiosperms and Gymnosperms?
Angiosperms and gymnosperms are the two major groups of vascular seed plants. Angiosperms, which are flowering plants, are the largest and most diverse group within the kingdom Plantae. With around 300,000 species, they represent approximately 80 percent of all the known green plants now living.
Plant - Conifers, Cycads, Ginkgoes | Britannica
2024年11月18日 · The term gymnosperm (“naked seeds”) represents four extant divisions of vascular plants whose ovules (seeds) are exposed on the surface of cone scales. The cone-bearing gymnosperms are among the largest and oldest living organisms in the world. They dominated the landscape about 200 million years ago.
Ginkgo | Description, Natural History, & Uses | Britannica
2024年10月30日 · ginkgo, (Ginkgo biloba), deciduous gymnosperm tree (family Ginkgoaceae), native to China. Ginkgo has been planted since ancient times in Chinese and Japanese temple gardens and is now valued in many parts of the world as a fungus - and insect -resistant ornamental tree.
Angiosperm - Flowering, Monocots, Dicots | Britannica
2024年10月22日 · Angiosperm - Flowering, Monocots, Dicots: The angiosperms are a well-characterized, sharply defined group. Most typically, angiosperms are seed plants; this separates them from all other plants except the gymnosperms.
Angiosperm - Flowering, Pollination, Reproduction | Britannica
2024年10月22日 · What are angiosperms? How are angiosperms different than gymnosperms? How are angiosperms and gymnosperms similar?
Plant reproductive system - Gymnosperms, Pollination, Seeds
Plant reproductive system - Gymnosperms, Pollination, Seeds: The cycads are slow-growing dioecious (species with individuals that are either male or female) gymnosperms, the microsporangia (potential pollen) and megasporangia (potential ovules) occurring on different individual sporophytes.
Gymnosperm - Evolution, Paleobotany, Reproduction | Britannica
2024年10月14日 · Gymnosperm - Evolution, Paleobotany, Reproduction: Gymnosperms were the first seed plants to have evolved. The extinct Progymnospermophyta is thought to be ancestral to seed plants.
Angiosperm - Flower, Pollination, Reproduction | Britannica
2024年10月22日 · What are angiosperms? How are angiosperms different than gymnosperms? How are angiosperms and gymnosperms similar?