Search results
Results from the WOW.Com Content Network
In bryophytes (mosses, liverworts, and hornworts), the gametophyte is the most visible stage of the life cycle. The bryophyte gametophyte is longer lived, nutritionally independent, and the sporophytes are attached to the gametophytes and dependent on them. [5] When a moss spore germinates it grows to produce a filament of cells (called the ...
In ferns and seed plants (including cycads, conifers, flowering plants, etc.) the sporophyte is the dominant generation; the obvious visible plant, whether a small herb or a large tree, is the sporophyte, and the gametophyte is very small. In bryophytes and ferns, the gametophytes are independent, free-living plants, while in seed plants, each ...
Bryophytes are characteristically limited in size and prefer moist habitats although some species can survive in drier environments. [4] The bryophytes consist of about 20,000 plant species. [5] [6] Bryophytes produce enclosed reproductive structures (gametangia and sporangia), but they do not produce flowers or seeds.
Antheridia and archegonia occur on different gametophytes, which are then called dioicous. The moss Mnium hornum has the gametophyte as the dominant generation. It is dioicous: male plants produce only antheridia in terminal rosettes, female plants produce only archegonia in the form of stalked capsules. [26] Seed plant gametophytes are also ...
Seed producing plants, which include the angiosperms and the gymnosperms, have a heteromorphic alternation of generations with large sporophytes containing much-reduced gametophytes. Angiosperms have distinctive reproductive organs called flowers, with carpels , and the female gametophyte is greatly reduced to a female embryo sac, with as few ...
Most bryophytes, such as these mosses, produce stalked sporophytes from which their spores are released. The non-vascular land plants, namely the mosses (Bryophyta), hornworts (Anthocerotophyta), and liverworts (Marchantiophyta), are relatively small plants, often confined to environments that are humid or at least seasonally moist.
A cluster of antheridia is called an androecium while a cluster of archegonia is called a gynoecium. (Note these terms have a different meaning when used to refer to flower structures.) Bryophytes have the most elaborate gametophytes of all living land plants, and thus have a wide variety of gametangium positions and developmental patterns.
Reproduction occurs when male and female gametophytes interact. This generally requires an external agent such as wind or insects to carry the pollen from the stamen to the vicinity of the ovule. This process is called pollination. In gymnosperms (literally naked seed) pollen comes into direct