Duba wurin da ke ƙasa sannan ka amsa tambayar daga baya a cikin harshe ɗaya kamar yadda wurin yake:  Hanyar wucewa: Kusan dukkanin rayuwar dabbobi a duniya sun dogara ne akan kwayoyin cuta don rayuwarsu kamar yadda kwayoyin cuta da wasu archaea ke da kwayoyin halitta da enzymes da ake buƙata don hada bitamin B12, wanda aka fi sani da cobalamin, kuma ya samar da shi ta hanyar sarkar abinci. Vitamin B12 shine bitamin mai narkewa a cikin ruwa wanda ke cikin metabolism na kowane kwayar jikin mutum. Yana da mahimmanci a cikin aikin al'ada na tsarin juyayi ta hanyar rawar da yake takawa a cikin haɗin myelin. Akwai kwayoyin kwayoyin cuta miliyan 40 a cikin gram na ƙasa da kwayoyin kwayoyin cuta miliyan a cikin mililita na ruwa mai kyau. Akwai kimanin kwayoyin cuta 5 × 1030 a duniya, suna samar da kwayoyin halitta wanda ya wuce na dukkan tsirrai da dabbobi. Kwayoyin cuta suna da mahimmanci a matakai da yawa na sake zagayowar abinci mai gina jiki ta hanyar sake amfani da abinci mai gina jiki irin su gyara nitrogen daga yanayi. Tsarin abinci mai gina jiki ya haɗa da lalatawar gawawwaki; kwayoyin cuta ne ke da alhakin matakin putrefaction a cikin wannan tsari. A cikin al'ummomin halittu da ke kewaye da magudanan ruwa da kuma ruwan sanyi, kwayoyin extremophile suna samar da abubuwan gina jiki da ake buƙata don ci gaba da rayuwa ta hanyar canza mahaɗan da aka narkar da su, kamar su hydrogen sulphide da methane, zuwa makamashi. Bayanai da masu bincike suka bayar a watan Oktoba na 2012 kuma aka buga a watan Maris na 2013 sun nuna cewa kwayoyin cuta suna bunƙasa a cikin Mariana Trench, wanda, tare da zurfin kilomita 11, shine mafi zurfin ɓangaren da aka sani na tekuna. Sauran masu binciken sun ba da rahoton binciken da ya shafi cewa microbes suna bunƙasa a cikin duwatsu har zuwa mita 580 a ƙarƙashin tekun a ƙarƙashin kilomita 2.6 na teku a gabar tekun arewa maso yammacin Amurka. A cewar daya daga cikin masu binciken, "Za ka iya samun ƙwayoyin cuta a ko'ina - suna da matukar dacewa da yanayi, kuma suna rayuwa a duk inda suke".An yi watsi da sanannen ra'ayin cewa kwayoyin cuta a jikin mutum sun fi ƙwayoyin mutum da kashi 10: 1. Akwai kimanin kwayoyin halittar kwayoyin cuta tiriliyan 39 a cikin kwayoyin halittar mutum kamar...  Tambaya: A cikin wane shekaru goma ne rarrabuwa kwayoyin cuta ya canza?
shekarun 1990s