Gymnosperms: haifuwa da kuma tsarin. Features na haifuwa na gymnosperms

Gymnosperms - shi ne mafi tsufa iri shuke-shuke a wannan duniya tamu. Sun taka muhimmiyar rawa a ci gaban da yanayi da kuma ci gaba da mamaye wani gagarumin matsayi a cikin rayuwar duniya. Sanannun mana spruce, Pine, fir, arborvitae, yews ko larch da kuma kadan da aka sani Welwitschia, saga ko ginkgo - duk mambobi ne na kungiyar, da ake kira "gymnosperms". Tsari da kuma waddan su za mu yi la'akari da daga baya a cikin wannan labarin.

The asalin da shekaru

Age gymnosperms - miliyan 350 shekara. Sun bayyana a cikin Upper Devonian (Paleozoic) da kuma farkon da Mesozoic zamanin ya wadãta. Mai yiwuwa su asalin ake dangantawa da wai juyin halitta na spore - ferns. Idan aka kwatanta da su, wani sabon nau'in shuka riga ya da ovules da pollen hatsi ne kai tsaye da hannu a cikin samuwar zuriyar. Akwai wani yawan abũbuwan amfãni mallaki by gymnosperms:

• haifuwa auku ba tare da sa hannu na ruwa.
• testa da kuma wadata da na gina jiki tsiraru da tabbatar da aminci da seedling.

Domin wadannan dalilai, wani gajeren lokaci daga baya da kore cover na duniya riga sa up wani babban ɓangare na gymnosperms, tsarin da haifuwa na da gudummawar da nasara cin gaban sabuwar yankunan da muhalli maharibai.

tsarin fasali

M mai suna shuke-shuke girma a cikin siffar itatuwan da shrubs, sau da yawa - Evergreen, kuma da wuya - deciduous. Wani lokaci su iya isa babbar masu girma dabam (redwood, da itacen al'ul). Bar da mafi yawan su allura-kamar ko da wani nau'i na flakes. Su kira needles, da kuma dauke da guduro motsa.

Wood sa up mafi daga cikin akwati. Ya ƙunshi m m cages tare da perforated ganuwar - tracheids. Su gaban - wani sifa cewa shi ne musamman domin wannan rukuni na shuke-shuke. Wannan shi ya sanya sama kwarara ruwa daga tushen da ganye.

Bugu da kari ga tracheids gymnosperms katako kuma ya hada da guduro Tsarki. Saboda haka, wakilan wannan rukuni na tsire-tsire masu saukin recognizable coniferous m wari. A guduro impregnates da itace, wanda ya hana shi daga Rotting. Saboda wannan, a cikin conifers haka da yawa centenarians. Alal misali, yana da shekaru da wasu daga cikin Sequoias yana game 3 dubu. Years.

A mafi muhimmanci juyin halitta bace cewa gymnosperms - haifuwa ba tare da takaice danshi da kuma gaban tsarin cewa aiki a matsayin masu haihuwa gabobin.

Haihuwa gabobin da gymnosperms

Babu launi - key siffofin da suke da gymnosperms. Multiplication da wadannan shuke-shuke faruwa tare da sa hannu na Cones, ko strobe. Wadannan tsarin ne sauki gane a kan Pine, spruce, fir, larch da kuma sauran wakilan da conifers. Jikinsu za a iya kira jima'i haifuwa.

Yawanci, Cones namiji - su zama namiji da mace, kuma located ko dai a kan wannan shuka (monoecious) ko daban-daban (iri guda ba), iri dabam-dabam a cikin size da kuma launi.

Male Cones kira microstrobiles da mata - megastrobilami. Strobila aka truncated da mutated kuɓuta, wanda aka located sporophylls - modified ganye. A microstrobiles girma pollen. A megastrobilah - ovules.

Features na haifuwa na gymnosperms

Yawanci gymnosperms haifuwa aiwatar la'akari da misali na Scots Pine. Yana da wani monoecious shuka, watau. E. Namiji da mace Cones shi ci gaba a cikin wannan itace. A farko daga cikin wadannan ya fi girma, m launi. Na biyu - kananan, greenish ko bluish.

gymnosperms waddan makirci ne mai sauki isa. Lokacin da microstrobiles girma pollen, shi ne zuba, yada da iska da kuma iya tafiya mai nisa. Don wannan karshen, kowane pollen hatsi sanye take da musamman na'urorin - pollen a tayakanmu ba. Wãtsarwa fada a kan ovules tasowa a kan megastrobilah. Wannan ya faru pollination.

Yana yakan auku a karshen spring ko farkon lokacin rani. Pollinate da mace Cones aka rufe, su Sikeli gam tare da guduro. Hadi auku a ovule ciki Samun rufe Cones.

Ta yaya ne tsari na hadi

Ciki da ovule ne mace gametophyte ko tayi jakar kwai, wanda da farko ya wuce da dama matakai na maturation. Hirtsinta samun a kan pyltsevhod ovule, shi fara girma a cikin pollen tube wajen archegonium (daga Girkanci arche - "farkon", tafi - "mahaifa"). Wannan samuwar ƙunshi kwai. Just ovule tasowa su biyu, amma daya kawai aka fallasa zuwa hadi.

A wannan batu a cikin pollen hatsi ne cikakke, biyu maniyyi da kuma fara gabatarwa da girma tube. Lokacin da daya daga ma'ana kai da kwai da aka hadu. Na biyu maniyyi da ya mutu. Bayan da ci biyu gametes kafa iri tayi - zygote. Shi da kansa ne ya canza kama zuwa ovule iri. Germinating, shi zai yi amfani da wadata da na gina jiki.

Wannan shi ne abin da ya faru haifuwa na gymnosperms. Tuki da wannan tsari da aka nuna a cikin photo.

Maturation da iri waste

Da zarar hadi ya faru, da maturation daga zurriyar fara. A Scots Pine, biyu daga cikin wadannan matakai šauki 2 shekaru. Ripening, Cones lignified da canji launi. A hankali, su Sikeli an buɗe, suka kuma zubo da tsaba.

Gymnosperms ba ta samar da 'ya'yan itace. Amma domin ya yada a tsawon nisa, da tsaba da musamman na'urar - reshe membranous outgrowths saukin aiwatar da iska. Idan waje yanayi ne m for germination, da iri iya zama dogon lokacin hutu kafin ganiya zazzabi. Wadannan siffofin yarda da gymnosperms cimma wani babban yawan jinsin da kuma yada a kan manyan yankunan.

Yawan jinsunan da kuma wakilan

Bayyana wani rukuni yana da game 600-700 jinsunan. Ba su suka tsira zuwa yau, wasu mambobin zama kawai yadda burbushin. Ga misali:

• kordaitovye.
• bennetitovye.
• iri ferns.

Sauran yada a duniya da kuma girma a duk canjin yanayin da, daga wurare masu zafi kudancin (sago dabino) zuwa ga sanyi arewacin latitudes (Pine, larch, spruce, Pine).

A mafi tsufa wakilin gymnosperms cewa wanzu a wannan rana - Ginkgo (biloba). Wannan inji aka kira wani rai m, saboda shi ke tsiro a duniya tare da Mesozoic zamanin, kamar yadda evidenced da yawa ragowar a sediments na zamanin d kankara.

juyin ci gaba

Da farko gymnosperms tasowa a cikin Paleozoic zamanin, yana da abũbuwan amfãni mãsu yawa suke taimaka musu a lokacin da za a yi a rinjaye matsayi a duniya. Wadannan sabon fasali ne juyin aromorphoses sunan da kuma damar kai wani sabon matakin a gaban sabon yankunan da muhalli maharibai. Ware wasu daga cikin siffofin da suke da gymnosperms:

1. Farfagandar ne da za'ayi ba tare da mai ruwa-ruwa matsakaici. Wannan ya yarda ya zauna manyan yankunan kan ƙasar.
2. Hadi auku a cikin ovule da aka kare daga waje ke tsoma - musamman irin haifuwa gymnosperms samar da mafi aminci daga cikin nan gaba shuka.
3. Ana zargin da iri tayi ne mai yiwuwa a tabbatar da makomar na murfin (testa) da kuma ikon ajiye (endosperm) wanda, bi da bi, ya kara yawan shuke-shuke na kungiyar.

Yana da wadannan halaye bambanta su daga kakanninsu - ferns. A na gaba, da kuma a yau na karshe mataki na juyin ci gaban da shuka duniya ne bayyanar angiosperms.

Ma'ana gymnosperms

Da muhimmancin da gymnosperms wuya a overestimate. Suka ciccika game da wani uku na duniya gandun daji, musharaka cikin tsabta iska da kuma m sabunta oxygen. Bugu da kari, da bayyanar da tartsatsi a cikin shuka duniya, samar da yawa oxygen, sakamakon bayyanar wasu kwayoyin iya yin amfani da wannan gas a aiwatar da numfasawa.

Conifers - babban kaya na itace daban-daban duniyoyin na rayuwar dan Adam. Wadannan albarkatun kasa ake rayayye amfani a yi na furniture, yi, samar da tasoshin da kuma sauran yana kokarin muhimmanci tattalin arziki aiki. Spruce itace zaruruwa ne musamman m a yi na high quality-takarda maki.

Gymnosperms suna yadu amfani da magani. Special abubuwa - maras tabbas kasaftawa kusan duk conifers ne iya tsabtace iska na germs. Saboda wannan dalili, yawancin cibiyoyin kiwon lafiya da kuma cibiyoyin kiwon lafiya gina a kan ƙasa na coniferous gandun daji. Irin wannan far iya muhimmanci rage ko kawar da yawa na huhu cututtuka.