Mene ne shawarwari a ilmin halitta: definition, sifa da aiki

A spores na rayayyun kwayoyin halitta - ban mamaki Kwayoyin. A duniya, su zama a cikin yanayi na sosai low ko high yanayin zafi, high matsa lamba da kuma rediyoaktif radiation. Yana tabbatar da cewa, shawarwari ne ko a sarari, tafiya a cikin sararin samaniya. Mene ne shawarwari a ilmin halitta? Mene ne sirrin da wadannan Kwayoyin?

Shawarwari: definition a ilmin halitta

Fassara daga Girkanci kalmar ma'ana "zuriya." Amma gaban wadannan Kwayoyin ba musamman ga shuke-shuke. Mene ne wata muhawara? A ilmin halitta, akwai bayyananne ra'ayi: shi ne sel sake yiwuwar tohowarsu. Tare da su taimako, da haifuwa tsari aka yi irin wannan kwayoyin kansu - celled kwayoyin da ba core.

Namomin kaza ne ma iya sporulation. Kowa da kowa ya gani yadda gurasa, wanda shi ne lokaci mai tsawo a cikin wani roba jakar fara da za a rufe shi da fari Bloom - shi suka fara samar kyawon tsayuwa. A tsawon lokaci, plaque fara saya a launin toka ko kore. Wannan yana nufin cewa naman gwari ya kafa spores da kuma fara ninka. A nan ne wani misali. A wani damp dakin kyawon tsayuwa sau da yawa samu a kan garun, wanda aka fara "fure". Rabu da mu da mold ne wuya, domin da naman gwari ne iya raba spores kan wani nesa na mitoci da dama.

tsarin

Saboda haka muna da siffa, abin da shawarwari. A ilmin halitta, duk suna zaune abokai suna bi cikin sharuddan da dangantaka da tsarin da kuma ayyuka. sake yiwuwar tohowarsu Kwayoyin zo a cikin daban-daban siffofi: elliptical, m, zagaye. Tun da su ne resistant zuwa iri-iri na nazarin halittu dalilai, da farfajiya na na'urar da aka shirya a wani musamman hanya. Ya kunshi biyu bawo, da sarari tsakanin su mai cike da furotin da hadaddun mahadi da carbohydrates. Don karfafa kariya a kan inji tasirin ne wasu shawarwari a kan bãyan tẽkun, da ilimi na musamman, wanda ake kira "hakarkarinsa".

Ciki cell abun ciki na sake yiwuwar tohowarsu, aka wakilta cytoplasm - ciki semiliquid matsakaici. Yana shirya chromosome da kuma gina jiki kira na'ura.

rigingimu shuke-shuke

Tare da wadannan Kwayoyin, da yawa shuka kwayoyin ne domin haihuwa.

Spore shuke-shuke - shi ne mai na'urar ga haifuwa na farko kuma mafi m shuke-shuke. Wannan shi ne da farko algae. Alal misali, guda-celled siffofin zoospores chlamydomonas - motile Kwayoyin. A sakamakon haka, daya musamman hanya da dama m kwayoyin.

A farko baƙi a ƙasar, da hakan spore shuke-shuke, ne ma iya sporulation. Mosses, kulob din mosses, horsetails da ferns samar da wata musamman gabobin da sake yiwuwar tohowarsu - sporangia. Sun ƙunshi Kwayoyin da sake yiwuwar tohowarsu. Shuke-shuke da cewa suna da irin wannan jikin, da ake kira sporophytes. A mossy kafar sporangia gabatar da wani akwatin. Lokacin da cikakke, kwantena da aka bayyana, a cikin sel fada a cikin ƙasa. A gaban ruwa, suka germinate a jima'i tsara - gametophyte, wanda aka wakilta a gansakuka kore leafy "kafet". Quite daban-daban shi ne yanayin a cikin sauran 'yan spore-hali shuke-shuke da cewa an saba ganin matsayin gametophyte - kore shuka. A cikin wadannan shuke-shuke akwai wani tsari na canzawar jima'i da kuma asexual zamaninsu.

kwayan spores

Kwayan spores - shi ne ba wai kawai wata cell tare da kwayoyin ninka. A karkashin m yanayi da kwayoyin kare, ba ya mutu. Sai dai a cikin wata muhawara a cikin abin da adadin danshi ne ƙwarai rage, shi rage-rage na tsanani matakin na duk rayuwa tafiyar matakai. Lokacin da yanayi da ake canza ga mafi alhẽri, da shawarwari kuranye fata, ya zo daga wani cikakken mai yiwuwa kwayoyin. Daya iya cewa sporulation na kwayoyin cuta ba mai Hanyar haifuwa, da kuma yiwuwar su tsira.

Mene ne shawarwari a ilmin halitta ya dade da aka sani. Tun da farko rayayyun kwayoyin halitta ne da kiwo aiwatar da ya faru da taimakon wadannan Kwayoyin. Hakika, da rigingimu ba su samar da recombination kayyade abu, sakamakon zargin sabon amfani fasali ne kawai zai yiwu ba. Duk da haka, an daidai replica na jiki da kuma adana duk kaddarorin da rigingimu da tabbacin.