Plantae: diferenças entre revisões

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=== O grupo das Embryophyta ===
{{AP|Embryophyta}}
[[File:Ferns02.jpg|thumb|[[Pterydophyta]]: ''[[Dicksonia antarctica]]'', uma espécie de [[feto arbóreo]].]]
 
O maior grupo de plantas, e o mais familiar, são as [[plantas terrestres]] [[muticelular]]es que cosntituem o grupo conhecido por [[embriófitas]] ([[Embryophyta]]). As embriófitas incluem as [[planta vascular|plantas vasculares]], tais como os fetos, coníferas e [[plantas com flor]], mas também os [[briófito]]s, dos quais os [[musgo]]s e as [[Marchantiophyta|hepáticas]] são os tipos mais comuns.
 
Todas estas plantas apresentam células [[eucariota|eucarióticas]], com [[parede celular]] contendo [[celulose]], e a maioria obtém sua energia através da [[fotossíntese]], usando [[radiação solar]], [[água]] e [[dióxido de carbono]] para sintetizar alimentos. Cerca de 300 espécies de plantas não fotossintetizam, sendo parasitas de outras espécies de plantas fotossintéticas ou de fungos ([[micotrofia|plantas micotróficas]]), mas descendem de plantas fotossintéticas que perderam essa capacidade como carácter secundário de adaptação ao [[parasitismo]]. Os embriófitos distinguem-se das [[algas verdes]], que representam um modo de vida fotossintética semelhante ao tipo de planta moderna que se acredita ter evoluído a partir de linhagens dessa algas, por ter órgãos reprodutivos especializados protegidos por tecidos não reprodutivos.
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The plants that are likely most familiar to us are the [[multicellular]] land plants, called [[embryophyte]]s. Embryophytes include the [[vascular plant]]s, such as ferns, conifers and flowering plants. They also include the ''[[bryophyte]]s'', of which [[moss]]es and [[Marchantiophyta|liverworts]] are the most common.
 
All of these plants have [[eukaryote|eukaryotic]] cells with [[cell wall]]s composed of [[cellulose]], and most obtain their energy through [[photosynthesis]], using [[light]], water and [[carbon dioxide]] to synthesize food. About three hundred plant species do not photosynthesize but are [[parasite]]s on other species of photosynthetic plants. Embryophytes are distinguished from [[green algae]], which represent a mode of photosynthetic life similar to the kind modern plants are believed to have evolved from, by having specialized reproductive organs protected by non-reproductive tissues.
 
Bryophytes first appeared during the early [[Paleozoic]]. They are mainly live in habitats where moisture is available for significant periods, although some species, such as [[Targionia (plant)|''Targionia'']] are desiccation-tolerant. Most species of bryophytes remain small throughout their life-cycle. This involves an alternation between two generations: a [[haploid]] stage, called the [[gametophyte]], and a [[diploid]] stage, called the [[sporophyte]]. In bryophytes, the sporophyte is always unbranched and remains nutritionally dependent on its parent gametophyte. The embryophytes have the ability to secrete a [[Plant cuticle|cuticle]] on their outer surface, a waxy layer that confers resistant to desiccation. In the [[moss]]es and [[hornwort]]s a cuticle is usually only produced on the sporophyte. [[Stomata]] are absent from liverworts, but occur on the sporangia of mosses and hornworts, allowing gas exchange.