Muumambo hwemiriwo cotyledons vanoita basa rakakosha mukusimudzira uye kuberekesa kwemiti. Sezvakaita mhuka, phanerogamic zvirimwa zvinomuka kubva mudumbu rinokura mumatanho akateedzana. Shizha rekutanga kubuda kubva muchibereko chemuti chinoitika panguva yekutanga kukura kwemiti inonzi cotyledon.
Muchikamu chino tichaenda kukuudza zvese hunhu uye kukosha kwecotyledons.
Chii chinonzi cotyledons
Chinhu chekutanga chatinofanira kuziva ndiwo akakosha maitiro ecotyledons uye kuti anotangira sei. Patinotarisa pakudzidza bhotani, mashizha epamusoro emiti yemaruva anozivikanwa semaphanerogamu anonzi macotyledons. Aya macotyledon anokura pamwe nekumera kwembeu uye ndipo panogadzirwa shizha rekutanga re "embryo". Huwandu hwecotyledons huripo mumbeu hunoshandiswa senzira yekutsanangudza izvo phanerogamic zvirimwa. Botany yakashandisa iyi mhando yekutsanangudza kuti zvirinani kufungidzira dzakasiyana mhando.
Izvo zve telethon, nhungirwa uye midzi yezvirimwa zvimiro zvinokura panguva yeiyo embryogenesis maitiro asati amera. Embryogenesis ndiyo nzira inogadzirwa nhumbu. Mune ino kesi, "embryo" ndiyo inopa shizha rekare. Kubva pane shizha, dzinde uye zvimwe zvese zvinogadziriswa zvemiti ye phanerogam zvinotanga kukura. Ndiro shizha guru rinoona nezvekutambira zuva uye kutungamira kukura kwaro kwese zvichienderana nekwenongedzo yechiedza. Iyo iri zvakare mutariri wekutanga photosynthesis yekuchinjana kwezvakachenesa pamwe nharaunda.
Uye zvakare, kuitira kuti macotyledon akwanise kusiyaniswa kubva kune ese mamwe mashizha, unogona kuona kukura kwayo. Izvo zvinovaka muviri zvine zvimiro zvakaita semafuta, starch kana starch zvakakosha pakusimudzira chirimwa.
Mhando huru
Kana tangoziva kuti macotyledon chii uye kuti anotangira sei, tichaona kuti ndehupi hunhu hwavanadzo. Chekutanga pane zvese kuziva kuti ndeipi shizha rekutanga rinobuda muchibereko chemuti. Iri ndiro shizha riri pamusoro pekugona kukudziridza zvakasara zvemuti. Inosiyana zvakanyanya kubva kune mamwe mashizha nekuda kwehukuru hwayo. Inowanzo kuve saizi imwe chete yakakura kudarika mamwe ese. Huwandu hwemakotoni hunoshanda senzira yekuisa zvirimwa mubazi resainzi rinozivikanwa sebhotani.
Mune zvimwe zvirimwa zvepanerogamic iyo cotyledon yaive yekugaya iyo albenen. Albumen hapana chimwe kunze kwechinhu chakakomberedza iyo embryo. Mushure mekumera, albumen inoshandiswa sechikafu checotyledon. Aya ma cotyledon ari kuchengeta zvakasiyana zvinovaka muviri munyama yavo inoshanda mukukudziridza chirimwa. Uye zvakare, semidzi painenge ichikura, kuchinjana kwemakemikari kunowedzera kwete chete nenharaunda, asiwo nevhu. Shasha dzine hafu yeupenyu ipfupi nekuti, kana zvirimwa zvikaitika, mashizha ane basa rekuwana simba. Izvi zvinoita kuti macotyledon awire pamusoro penguva nekuda kwekushaikwa kwekushandisa.
Cotyledon mabasa uye kukosha
Ngatione kuti chiiko chinonyanya kushanda checotyledons mukati meiyo phanerogam zvirimwa. Isu tinoziva izvo zvakakosha zvivakwa muzvirimwa zvinopa zvinovaka muviri zvekusimudzira kana mhodzi yapera. Zvakare zvakakosha kuti zvirimwa zvikure. Rimwe remabasa makuru eiyo cotyledon kutora uye kuchengetera zvinovaka muviri zvakachengetwa mumbeu kusvika nguva yakwana iyo mbeu ichikwanisa kugadzira mashizha ayo chaiwo.
Kana chirimwa changokwanisa kugadzira chaicho mashizha echokwadi, ivo vari mukutarisira kwekugadzira maitiro ephotosynthesis uye kutora zvinovaka muviri kuburikidza nemwaranzi yezuva. Izvi pamwe chete nemidzi inogona kupinza mvura inozoishandura kuita muto wakajeka, chirimwa chinogona kurarama nekukura.
Cotyledons akakosha kumusara wemavara. Kutenda kuvapo kwecotyledons, machloroplast anoonekwa nawo anokwanisa kuita photosynthesis. Ndiwo ma chloroplast anopa mashizha awo ruvara rwegirini. Zvese zvimiro zvezvirimwa zvisina girini hazvina chlorophyll, inova ndiyo pigment huru inoitisa photosynthesis.
Monocotyledonous uye dicotyledonous zvirimwa
Sezvatakambotaura, mubhodani huwandu hwemacotyledon hunoshandiswa kuronga zvirimwa zviri nani. Ngatione kuti hunhu hweihwo neumwe hwakavakirwa pahuwandu hwecotyledons dzavanadzo:
Monocots
Zvinosanganisira angiosperm zvirimwa zvinozivikanwa nekuve necotyledon imwechete mumbeu. Kumera kwaro kunongova neshizha rimwe chete rechinyakare pachinzvimbo chemaviri. Miti iyi haina yechipiri kukura kwechipiri, saka haina trunk yechokwadi. Ivo zvakare havana chirimwa chemuti chakagadzirwa nemasero eumbryon. Aya marudzi ezvirimwa haakwanise kuburitsa huni uye chimiro chawo chinowedzera nekukudza iwo ma "internode" sezvo chirimwa chiri kukura
Muenzaniso chaiwo wezvirimwa zvine monocotyledonous huswa hwatinowana zviyo zvakawanda zvakaita segorosi, chibage kana nzimbe. Maruva, miti yemichindwe, jonquil, tulips, hanyanisi kana maorchid zvakare zvirimwa zvine monocotyledonous.
Dicotyledons
Ndeavo vane mbiri dzakafukurwa mumbeu yavo. Ndiwo akanyanya kuwanda boka uye panomera. Mashizha maviri echinyakare anogadzirwa anoshanda sekudya kwembeu nyowani. Mashizha e dicotyledonous zvirimwa anogona kutora akasiyana mafomu zvichienderana nezvinhu zvakawanda. Iko kune moyo-wakaumbwa, ribhoni, mukomboni, nezvimwe. Ivo vanogona zvakare kuve akajeka kana akareruka mativi. Iwo matavi ezvirimwa aya anoumbwa nemakete egore uye akaumbwa ne xylem uye phloem ayo ari muto-unoitisa matishu. Uye zvakare, ivo vanokwanisa kugadzira huni kana huni.
Mukati meboka remakwenzi ane dicotyledonous atinawo Rosaceae, nyemba uye Rutaceae. Semarudzi, tine fodya, bhinzi, soya, pizi, nhova, madhiriji, maringazuva, kofi, carob, marosi, avocado kana cherries.
Ndinovimba kuti neruzivo urwu iwe unogona kudzidza zvakawanda nezve cotyledons uye kukosha kwavo.