Gymnosperms

Gymnosperms tifufuza mbiriyakale awo pa nthawi ya paleofita. Icho chiri cha mbiri yakale wa mbewu amakhala ndi spore ambiri. Iwo anali akuluakulu oimira zomera ndi. Mochedwa Permian nthawi zomera kumabweretsa kusintha kwakukulu: m'malo nyengo zithaphwi khala ndi zomera yawo ikadzawadzera nthawi kwathunthu zomera zosiyanasiyana. Gymnosperms makamaka azipeza ndi maudindo kutsogolera mu nthawi ya Mesozoic.

Zikamera wa gulu la zomera linali lofunika mwapang'onopang'ono mchitidwe wa chisinthiko. China Fern mu ndondomeko kuswana sing'anga amadzimadzi chofunika. Mkangano, chotuluka mwa sporangium m'nthaka lonyowa kumera prothallia ndi maliseche. Ngati mbewu mu chitukuko cha mitundu spores zosiyanasiyana, ena a iwo osauka prothallia awiri: wamkazi mmodzi ndi zina ziwalo mwamuna. Komanso ndondomeko ya umuna kuchitika archegonium - wamkazi selo - ndi kulumikiza ndi mwamuna selo kugonana, mu nkhani iyi choyambilira ndi kupezeka kwa madzi. Zoonadi mfundo imeneyi ndi chakuti Mumapezekanso analipo ndi psilophytes kusanduka kuchokera ku zomera za m'madzi. Izi Mbali chomwecho kwambiri okha kufalitsa zomera - zomera akhoza kudzachitika pokhapo mu malo ndi chinyezi mkulu.

Gulu latsopano anataya kudalira kukhalapo kapena kusapezeka kwa madzi. A kubalana wa gymnosperms zomera motere: mphepo amanyamula mungu ndi mbewu chitukuko kupita kumanja pa kukopera akuchikazi. Koma uwu si ntchito kokha pa gululo. Ngati otsutsa okha 1 selo, umene uli zochepa kundipatsako kwa zakudya, ndiye mbewu ya maphunziro kale multicellular, anaonetsetsa kundipatsako kwa zinthu zofunikira pa chitukuko embryonic. Komanso, pamaso pa mamba mbewu Ndisanaumbidwe Mwachibadwa odalirika chitetezo ku ngozi zachilengedwe. Izi zinthu zatsopano za kapangidwe ndi wofunika kwa zamoyo wa zomera ndi; gymnosperms kupeza zinthu bwino chifukwa kuswana ndi kusamala.

Today zomera ndi akatswiri wolemekezeka mu kalasi osiyana. Ndipo mbiri yonse ya chitukuko zikutsimikizira kuti zimenezi zinachitika angiosperms ku gymnosperms. mamembala onse a gulu (gymnosperms) anagawa m'zigawo zinayi: ginkgovidnye, gnetophyta, cycad, conifers.

chimagwirizanitsa Kodi gulu ili? ndi zizindikiro za gymnosperms chiyani? Onsewo ndi zitsamba kapena mitengo, nthawi zambiri kukula kwambiri. Ena, silnovetvyaschiesya, kusiyana ndi ambiri masamba ang'ono (kungakhale wazikang'a). Komabe, ena pang'ono nthambi, koma masamba yaikulu feathery. Xylem popanda ziwiya, phloem mnzake selo-free - khalidwe lina lofala kuti gymnosperms kwambiri. Iwo heterosporous. The mawonekedwe, kukula ndiponso dongosolo la micro- ndi makrosporofill osiyana kwambiri. Free kukula pa chipulumutso ochiritsira - kuchokera wosazindikira mbewu fern pa strobilae (mphukira lalifupi) - gymnosperms ina.

Mungu pores kapena chitsotso cha fumbi - izo microspores, malo amene - mungu sac. Ndi mphepo awo amanyamula gametophyte wamkazi. The ovule ndi akupangidwa kale megaspory. Pa umuna wamwamuna gamete ovule amakhala mbewu. Chinthu chapadera wa gametophyte wamkazi - kukana kwa madzi m'thupi. mbewu wazunguliridwa ndi malo michere, amene amagwiritsa zygote m'kati kumera, koma pamaso pa isanayambike zinthu yabwino kwa mbewu imakhalabe m'chigawo chete. Zipatso si anapanga, koma mbewu chingathe kukhala zosiyanasiyana zipangizo.