Combinative canzawa da juyin muhimmanci

Combinative canzawa ne mai babbar hanyar intraspecific bambancin da duk rayayyun kwayoyin halitta. Amma irin wannan kwayoyin canji kaiwa kawai zuwa samuwar sabuwar haduwa da dabiu riga ba. Kuma ba combinative canzawa da sunadaran ba sa bayyanar da ta sha bamban gene haduwa. Ana zargin gaba ɗaya sabon Properties saboda da daban-daban gene bambancin, zai yiwu ne kawai a yanayin saukan intraspecific mutational canje-canje.

Combinative canzawa ƙaddara da yanayin da haihuwa tsari. Domin irin wannan kwayoyin canji halayyar bayyanar sabon genotypes a kan tushen da sabuwar kafa gene haduwa. Combinative canzawa bayyana kanta riga a cikin lokaci na samuwar gametes (jam sel). Haka kuma, a kowane irin cell da aka wakilta daya kawai homologue chromosome daga kowane biyu. Halin da gaskiya cewa chromosomes fada cikin jam cell da ka, inda gametes a daya kwayoyin iya bambanta karfi isa a gene sa. Shi ba ya bayyana a wani canje-canje a cikin sinadaran halitta na kai tsaye m na hereditary bayanai.

Saboda haka, combinative canzawa ne saboda da dama recombination kwayoyin halitta ne riga ba a cikin chromosome sa. Wannan irin kwayoyin gyara kuma ba da conjugate da canje-canje a chromosome kuma gene Tsarin. Sources combinative canzawa iya zama kawai da matakai da cewa faruwa a lokacin da rage cell division (meiosis) da kuma hadi.

Elementary (karami) naúrar daban-daban recombinations hereditary abu, haddasa samuwar sabuwar gene haduwa, da ake kira recon. Kowane recon yayi dace da biyu nucleotides (ginin abu na nucleic acid) a cikin biyu-stranded DNA din da kuma guda nucleotide, a lokacin da ta je da tsarin da guda-stranded nucleic acid ƙwayoyin cuta. Recon ba divisible lokacin da hayewa (musayar aiwatar tsakanin su guda biyu homologue chromosomes a lokacin Tasrifu) da kuma a cikin dukkan lokuta daukar kwayar cutar a cike.

Combinative canzawa a eukaryotic Kwayoyin a hanyoyi uku:

1. Halitta recombination a kan aiwatar da mararraba-kan, inda ya isa cikin chromosomes suna kafa da ciwon sabon haduwa da alleles.
2. Independent bazuwar watsawa na chromosomes a lokacin anaphase na farko meiotic division mataki, inda dukkan gamete saya nasu kwayoyin fasali.
3. Casual ci karo da jam sel a lokacin hadi.

Saboda haka, ta hanyar wadannan uku sunadaran combinative canzawa kowane cell zygote kafa ta Fusion na gametes, yakan mallaki wata gaba daya sa na musamman da kwayoyin bayanai. Da cewa irin wannan gyare-gyare hereditary bayyana babbar bambancin cikin jinsin. Halitta recombination ne musamman da muhimmanci ga ci gaba da wani jinsin, kamar yadda aka halicce su ne ta m iri-iri na genotypes. Wannan ba wani heterogeneity na yawan jama'a. A bayyanar kwayoyin, mãsu ƙarfin niyya da kansa mutum halaye, da kayyade high dace da zabin yanayi, ba shi da damar barin kawai mafi nasara hade da hereditary halaye. Godiya ga kunsawa na sabon kwayoyin da haihuwa tsari, da kayyade abun da ke ciki an ci gaba da inganta.