Search results
Results From The WOW.Com Content Network
Prothallus of the tree fern Dicksonia antarctica (note new moss plants for scale) Spore-bearing plants , like all plants, go through a life-cycle of alternation of generations . The fully grown sporophyte , what is commonly referred to as the fern , produces genetically unique spores in the sori by meiosis .
Land plants evolved from a group of freshwater green algae, perhaps as early as 850 mya, [3] but algae-like plants might have evolved as early as 1 billion years ago. [2] The closest living relatives of land plants are the charophytes, specifically Charales; if modern Charales are similar to the distant ancestors they share with land plants, this means that the land plants evolved from a ...
The haploid prothallus does not resemble the sporophyte, and as such ferns and their allies have a heteromorphic alternation of generations. The prothallus is short-lived, but carries out sexual reproduction, producing the diploid zygote that then grows out of the prothallus as the sporophyte.
In most ferns, for example, in the leptosporangiate fern Dryopteris, the gametophyte is a photosynthetic free living autotrophic organism called a prothallus that produces gametes and maintains the sporophyte during its early multicellular development.
Many crustose lichens have a ring of unlichenised fungal hyphae at their edges. This fringe, known as a prothallus, may be black, white or the same colour as the rest of the thallus. [26] The term "crustose" derives from the Latin crustosus, meaning "crusted". [27]
A pteridophyte is a vascular plant (with xylem and phloem) that reproduces by means of spores.Because pteridophytes produce neither flowers nor seeds, they are sometimes referred to as "cryptogams", meaning that their means of reproduction is hidden.
This glossary of botanical terms is a list of definitions of terms and concepts relevant to botany and plants in general. Terms of plant morphology are included here as well as at the more specific Glossary of plant morphology and Glossary of leaf morphology.
Once fertilised, the cell can divide and the new baby fern starts to grow with help from the prothallus, which supports it with nutrients. [9] After a while when the fern has established its own root system and can continue growing on its own, the prothallus dies. A new life cycle can now begin when the fern grows towards maturity. [12]