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BRYOPHYTES (23.3). Tasha Fisher and Emily Crawford. What are Bryophytes?. Archidium ohioense, a moss. Include the mosses, liverworts, and hornworts. Are the simplest of plants. About 20,000 species Found throughout the world, but are prevalent in moist and shady areas
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BRYOPHYTES (23.3) Tasha Fisher and Emily Crawford
What are Bryophytes? Archidium ohioense, a moss • Include the mosses, liverworts, and hornworts. • Are the simplest of plants. • About 20,000 species • Found throughout the world, but are prevalent in moist and shady areas • can be found in alpine regions, where they are subjected to freezing, and some in deserts, where they are desiccated most of the time • Many are highly specialized, and found in restricted habitats
Unique Characteristics Lack of Vascular Tissue Gottschelia schizopleura, a liverwort • Lack vascular tissue • must absorb all water and nutrients at the surface and pass them from cell to cell. • few have modified water transport cells called hydroids, and a few have solute conducting cells, called leptoids, but this is rare. • leaves are not true leaves because most species lack vascular tissue. • Leaves are functionally equivalent to “real leaves” because they contain chlorophylls a and b. • “Leaves” are usually one-cell thick, except for the midrib, which may be up to 15 cells thick. • satisfy their nutritional requirements by absorbing minerals from dust, rainfall, and water running over their surface.
Unique Characteristics Phaeocerosoreganus, a hornwort • Bryophytes are small and the tallest are 20 cm in height while the shortest are about 2 cm in height. • Often grow in prostrate masses or clumps because they don’t have any vascular tissues needed for upright growth. • They do not have roots therefore they attach to the soil with rhizoids. • Most of them are soft and pliable.
Unique Characteristics Barbula indica, a moss • Survive best in moist habitats but many can tolerate dry areas by lowering metabolic needs. • Also known as desiccating • All mosses, liverworts, and hornworts have three traits that they share and that evolved in early plants: a waxy cuticle, cellular jacket, and large gametophytes. • If they dry out, they can simply be revived by water.
Uses of Bryophytes Japanese Moss Garden • Mosses are used in gardening, agriculture, medicine, and the construction of homes. • Other uses for mosses are all-natural insect repellants, boot liners, and fuel. • Liverworts are sometimes used for medicinal purposes. • They also very useful in determining any environmental changes.
Life Cycle of Bryophytes • Varies among the three divisions • In General…. • Sperm is released from the antheridium and uses water to reach the egg in the archeogonium. • A zygote forms and undergoes mitotic division until it develops into an embryo. • Embryo grows until it becomes a sporophyte in which spores form. • The spores are then released and germinate. The spores will form either male or female gametophytes.