A rayuwa ta sake zagayowar na sel - lokacin daga ta haihuwa zuwa wani m division ko mutuwa

A rayuwa ta sake zagayowar daga Kwayoyin - haila daga cikin na farko guda ɗaya na da mai rai daga kafuwar ta zuwa da kansa rabo na rabo ko mutuwa. Yana hada da dukan halitta canje-canje da cewa sha da wasu gabbansa dauke da fitar da ayyuka.

Dangane da kungiyar da kuma specialization misali cell sake zagayowar iya wuce a minti 30 da kuma 3 days. Alal misali, lokacin da crushing da Kwayoyin a echinoderms da rai sake zagayowar ne da minti 30, da kuma hanji epidermis a cikin mutane - ta 12 hours. Akwai kuma wadanda asali raka'a rai, wanda ba a raba, watau, ba haifa, suna yin su yi nufi aiki da kuma mutu - .. Irin yadda jijiya, striated tsoka zaruruwa. Kai cell rai sake zagayowar za a iya raba biyu lokaci: Interphase, ko da lokaci na ci gaba da mitosis - lokacin division. Interphase hada da, bi da bi, wani yawan bulan:

1. G1 (postmitotic) - na farko ci gaban zamani. A wannan mataki, taron na mRNA, sunadaran da sauran cell aka gyara.
2. S (roba) - auku DNA kwafi, wadda take kaiwa zuwa wani maimaitawan kayyade abu. A karshen zamani biyu na wannan nau'i DNA biyu Helix. Kowace daga cikin strands na deoxyribonucleic acid qunshi daya karkace haihuwa, da kuma na biyu - wani sabon daya, wanda aka kafa a kan tushen complementarity.
3. G2 (premitotic) - shi ne gyara tsari, wanda ya hada da gyaran kurakurai sanya a lokacin DNA kira a baya lokaci. Tara na gina jiki, makamashi, ci gaba da haduwa sunadaran da RNA.

A key kashi ne haifuwa mitotic sake zagayowar daga cell proliferative ko wanda zai fara kai tsaye bayan G2. Shi ne mai sa na matakai da faruwa a cikin na farko tsarin naúrar na rai daga daya rabo ga sauran karshen kuma samar da wani sabon ƙarni na na biyu Kwayoyin. Mitosis ne babban irin somatic division (ba musharaka cikin jima'i haifuwa) na na farko raka'a nukiliya kwayoyin.

A rayuwa ta sake zagayowar na sel da muhimmanci ga jikin, samar da aminci da lambar kuma siffar chromosomes halayyar kowane jinsi (karyotype), don haka yana da muhimmanci cewa duk division lokaci sun wuce ba tare da wani tashin hankali. Mitosis aka hada da 4 a jere bulan:

1. Prophase. A wannan lokacin, da cell division ya auku da kuma hilafa tsakanin sandunan centrioles, wanda ake juna ta dogara sanda division. By karshen wannan lokaci nucleoli hargitse chromosome thickened da kuma taqaitaccen, Ina nufin ne su sandaro.
2. Metaphase. Nucleoprotein tsarin hada kai tare ekweita Kwayoyin kafa metaphase farantin. Zo da primary constriction na chromosomes. Sa'an nan, kowane daga cikinsu ne zuwa kashi biyu chromatids.
3. Anaphase. A wannan lokaci obrazovashiesya ya chromosomes matsawa zuwa daban-daban sandunan, inda su ne lebur fitar da unwind.
4. Telophase. Mayar da nucleolus da core rabo daga cytoplasm faruwa.

Saboda haka, tantanin halitta sake zagayowar - lokacin rayuwa daga haihuwa zuwa na farko naúrar na mutuwa daga mai rai.