Kwafi - a maimaitawan: a cell daga cell

Anya samuwar biyu m kofe - wani sabon abu quite al'ada a nazarin halittu tsarin. Sau da yawa wannan kaida na maimaita abu ne ake kira kwafi. A karshen iya faruwa a bangarori daban-daban na tsara kwayoyin halitta - kai tsaye daga DNA to chromosomes da dukan Kwayoyin. A lokaci guda, idan aiwatar tafi smoothly, samu biyu m raka'a. Kwafi - a cire tallafin yanzu kayan ado.

Yadda daidai babu inda

The mafi ban sha'awa da kuma tushe ga duk wasu jinsunan da aka dauke su DNA kwafi. Yana da wani tsari da yake faruwa a kan da dama, saukarwa, kowanne daga abin da daidaito shi ne m, saboda inaccuracy fararwa da kira na da cikakken m gina jiki m don amfani a cikin cell da kuma a cikin kwayoyin a matsayin dukan.

Masomin

Kwafi farawa da cell anya DNA, wadda yana da sakamako na anya chromosomes. Amma kwafi - shi ne madogara na dukan tsari. Ya kunshi matakai uku: da farko, qaddamarwa, abu na biyu, elongation, da kuma uku, ƙarshe. The aiki ta fara da enzyme m maki - replicators kuma kawai tare da su. Farko a cikin kuskure wuri zai karkatar da magana, dukan tsari. A enzyme-mai kara kuzari activates takamaiman sunadaran cewa, samar da pre-kwafi hadaddun ake bukata domin DNA maimaitawan. Kafin multiplication na DNA da aka yanka a cikin sassa biyu da takamaiman enzymes.

A karin sarkar

Lokacin da elongation a kan matrix gina karin iyaye sarkar. Wannan shi ne, wanda zai iya sa'an nan ta samar da wani cikakken kwayoyin. A tsari ƙare da wani karewa cewa ma auku a wani batu. Akwai na musamman naúrar - da replicon. Wannan ne DNA gutsure cewa gina up a kan lokaci. DNA kwafi - kafuwar, ba tare da shi ba za a iya replicated chromosomes. A karshen faruwa a lokacin wani cell shirya su raba.

Protein kamar yadda wata ãyã

Ya fara chromosome maimaitawan a cikin 'yan sa'o'i bayan ta faru DNA maimaitawan. Don sake gina chromosome, muna bukatar ba kawai sabon sets na deoxyribonucleic acid, amma kuma sunadarai da cewa wani bangare ne na chromosome na'ura, da kuma su kira na bukatar lokaci. Fast kwafi - da wata ãyã daga ciwon daji. Idan shi detects da yawa gina jiki, halayyar m cell division, likita yana farawa da sautin ƙararrawa.

sarari isasshen

Akwai a cikin tsari na kwafi ne mai girma fasalin - a kwaya sarari cikin sharuddan kira na sabon DNA suna fairly a ko'ina, don haka babu murdiya, wanda zai iya tsokana a juna tasiri. Popular mai yawa da maki, yawanci da rabi zuwa biyu dozin.

Yadda daidai za a shirya chromosomes ya dogara a kan faruwa a cikin cell mitosis ko meiosis. A cikin farko idan, sakamakon cell zai zama saba sa, a karo na biyu - rabin. Bayan duk, da sauran rabin zai kawo wata cell na biyu da abokin tarayya a cikin jima'i haifuwa. Idan a meiosis ba zato ba tsammani samun cikakken sa, gamete ko zama unsustainable, ko so da ɗaukar cikin wani rashin lafiya yaro. Duk da haka, wadannan yara har yanzu suna haife mafi sau da yawa fiye da ba, akwai mai ashara a farkon ciki, uwar wanda zai iya kai a kan wata-wata ovulation ko zub da jini a tsakiyar sake zagayowar.