{"id":60740,"date":"2015-12-19T22:59:27","date_gmt":"2015-12-19T20:59:27","guid":{"rendered":"http:\/\/www.sorubak.com\/blog\/?p=60740"},"modified":"2015-12-19T22:59:27","modified_gmt":"2015-12-19T20:59:27","slug":"mayoz-bolunme-sirasinda-kalitsal-cesitlilige-neden-olan-olaylar-nedir","status":"publish","type":"post","link":"https:\/\/www.sorubak.com\/blog\/mayoz-bolunme-sirasinda-kalitsal-cesitlilige-neden-olan-olaylar-nedir.html","title":{"rendered":"Mayoz b\u00f6l\u00fcnme s\u0131ras\u0131nda kal\u0131tsal \u00e7e\u015fitlili\u011fe neden olan olaylar nedir?"},"content":{"rendered":"

Mayoz b\u00f6l\u00fcnme s\u0131ras\u0131nda kal\u0131tsal \u00e7e\u015fitlili\u011fe neden olan olay, \u00a0mitoz b\u00f6l\u00fcnme kal\u0131tsal \u00e7e\u015fitlilik sa\u011flar m\u0131,\u00a0mayoz b\u00f6l\u00fcnme kal\u0131tsal \u00e7e\u015fitlilik<\/strong><\/p>\n

E\u015feyli \u00dcreme ve Kal\u0131tsal Varyasyon<\/strong><\/p>\n

Yery\u00fcz\u00fcnde ya\u015fayan ayn\u0131 t\u00fcre ait bireyler birbirlerine benzemelerine ra\u011fmen baz\u0131 farkl\u0131l\u0131klara da sahiptirler. E\u011fer bu farkl\u0131l\u0131klar genler taraf\u0131ndan aktar\u0131l\u0131yorsa kal\u0131tsal varyasyon olarak adland\u0131r\u0131l\u0131r. E\u015feyli \u00fcreme baz\u0131 mekanizmalarla kal\u0131tsal varyasyonlar\u0131n ortaya \u00e7\u0131kmas\u0131nda rol oynar.<\/p>\n

Bunlardan birincisi mayoz b\u00f6l\u00fcnmede homolog kromozomlar\u0131n ba\u011f\u0131ms\u0131z da\u011f\u0131l\u0131m\u0131d\u0131r.\u0130kincisi yine mayoz b\u00f6l\u00fcnme s\u0131ras\u0131nda krossing overin ger\u00e7ekle\u015fmesidir.Kal\u0131tsal \u00e7e\u015fitlili\u011fin<\/strong> \u00fc\u00e7\u00fcnc\u00fc kayna\u011f\u0131 ise rastgele d\u00f6llenmedir.<\/p>\n

Mayoz B\u00f6l\u00fcnmenin temel \u00f6zellikleri:<\/strong>
\n1-Sadece 2n kromozomlu h\u00fccrelerde g\u00f6r\u00fcl\u00fcr.
\n2-2n kromozomlu h\u00fccrelerden n kromozomlu 4 h\u00fccre olu\u015fur.
\n3-iki karyokinez ve iki sitokinez g\u00f6r\u00fcl\u00fcr.
\n4-E\u015fey ana h\u00fccresi ve spor ana h\u00fccrelerinde g\u00f6r\u00fcl\u00fcr.
\n5-B\u00f6l\u00fcnme sonunda gamet ve sporlar olu\u015fur.
\n6-Kal\u0131tsal \u00e7e\u015fitlilik nedenidir.Olu\u015fan h\u00fccreler kal\u0131tsal olarak birbirinden farkl\u0131d\u0131r.
\n7-E\u015feyli \u00fcremenin temel mekanizmas\u0131d\u0131r.
\n8-Mitoza g\u00f6re daha ileri bir \u00f6zelliktir
\n9-Hem homolog kromozomlarda hemde karde\u015f kromatidlerde ayr\u0131lma g\u00f6r\u00fcl\u00fcr.
\n10-Sinaps, tetrad ve krossing-over g\u00f6r\u00fcl\u00fcr.
\n11-Mayoz ge\u00e7irmi\u015f h\u00fccre tekrar mayoz ge\u00e7iremez ancak mitoz ge\u00e7irebilir.<\/p>\n

Mayozun evrimsel \u00f6nemi:<\/strong>
\n1-Krossing-overle kal\u0131tsal \u00e7e\u015fitlilik<\/strong> sa\u011flar
\n2-Kromozom say\u0131s\u0131n\u0131 yar\u0131ya indirerek, d\u00f6llenme sonunda t\u00fcre \u00f6zg\u00fc kromozom say\u0131s\u0131n\u0131n sabit kalmas\u0131n\u0131\u00a0 sa\u011flar.<\/p>\n

A)Mayoz-1 evreleri: <\/strong>
\nMayoz b\u00f6l\u00fcnme homolog kromozomlar\u0131n ve karde\u015f kromatidlerin ayr\u0131lmas\u0131n\u0131 sa\u011flayan ard\u0131\u015f\u0131k iki b\u00f6l\u00fcnme b\u00fct\u00fcn\u00fcd\u00fcr. Homolog \u00a0kromozomlar\u0131n ayr\u0131lmas\u0131na neden olan birinci evreye Mayoz-1 evreleri denir.<\/p>\n

a)Profaz-1 <\/strong>
\n1-Sentroiller kutuplara hareket eder.
\n2-Nucleus zar\u0131 ve e.r. zarlar\u0131 erimeye ba\u015flar.
\n3-\u0130\u011f iplikleri olu\u015fmaya ba\u015flar.
\n4-Kromozomlar k\u0131sal\u0131p kal\u0131nla\u015fmaya ba\u015flar. Ancak profaz-1\u2019 de Mitoz profaz\u0131nda ve profaz-2 \u2018de g\u00f6r\u00fclmeyen baz\u0131 \u00f6zg\u00fcn olaylar ve kromozomlar\u0131n \u00f6zel davran\u0131\u015flar\u0131 vard\u0131r. Bu nedenle \u00a0profaz-1\u00a0 kendi i\u00e7inde be\u015f alt evrede incelenir.<\/p>\n

b)Metafaz-1<\/strong>
\n1-Homolog kromozomlar (Tetradlar halinde) ekvatoral plak \u00fczerinde kar\u015f\u0131l\u0131kl\u0131 dizilirler.
\n2-Her kromozom sentromeri ile i\u011f ipliklerine tutunurlar<\/p>\n

c)Anafaz-1<\/strong>
\n1-Homolog kromozomlar i\u011f iplikleri ile z\u0131t kutuplara do\u011fru \u00e7ekilirler.
\n2-Karde\u015f kromatidleri bir arada tutan sentromerler par\u00e7alanmam\u0131\u015ft\u0131r.
\n3-Kiyazmalar kromozomlar\u0131n ucuna do\u011fru kayarak ortadan kalkar.
\n4-Anne ve babadan\u00a0 gelen kromozomlar\u0131n kutuplara ta\u015f\u0131nmas\u0131 rasgele olur buda \u00e7e\u015fitlilik nedenidir.<\/p>\n

d)Telofaz-1 <\/strong>
\n1-Kromozomlardaki helixler \u00e7\u00f6z\u00fcl\u00fcr.
\n2-Nucleus zar\u0131 belirginle\u015fir.
\n3-Sitokinezle iki h\u00fccre olu\u015fur.
\n4-Olu\u015fan h\u00fccrelerin kromozom yap\u0131s\u0131\u00a0 n2c dir.
\n5-Erkeklerde sekonder spermatositler olu\u015fur.
\n6-Di\u015filerde ikincil oosit ve birinci kutup h\u00fccresi meydana gelir.
\n7-Mayoz ge\u00e7iren baz\u0131 h\u00fccrelerde nucleus zar\u0131 olu\u015fmaz ve kromozomlar helixler \u00e7\u00f6z\u00fclmez.
\nAra interfaz:Nucleolus g\u00f6r\u00fclmez,DNA ve RNA sentezi g\u00f6r\u00fclmez. H\u00fccredeki haz\u0131rl\u0131klar t\u0131pk\u0131 \u00f6nceki interfaz\u0131n devam\u0131 gibidir.<\/p>\n

\"MAYOZZZ\"<\/a><\/p>\n

B)Mayoz-II evreleri<\/strong>
\nKarde\u015f kromatidlerin ayr\u0131lmas\u0131n\u0131 sa\u011flayan ikinci b\u00f6l\u00fcnme evrelerine Mayoz-2 evreleri denir. Mayoz interfaz\u0131nda g\u00f6r\u00fclen olaylar mitoz interfaz\u0131 ile ayn\u0131d\u0131r.<\/p>\n

a)Profaz-II<\/strong>
\n1-Birinci b\u00f6l\u00fcnmede olu\u015fan i\u011fipliklerine\u00a0 dik olarak i\u011f iplikleri olu\u015fur.
\n2-Olu\u015fmu\u015fsa nucleus zar\u0131 kaybolur.
\n3-Helixlerini \u00e7\u00f6zen kromozomlar tekrar helixlerini olu\u015fturur.<\/p>\n

b)Metafaz-II<\/strong>
\n1-Kromozomlar ekvatoral d\u00fczlemde yanyana dizilirler
\n2-Kromatidler sentromerleri ile bir aradad\u0131r
\n3-Kromozomlar sentromerleri ile i\u011f ipliklerine tutunurlar<\/p>\n

c)Anafaz-II<\/strong>
\n1-\u0130\u011f ipliklerinin itme ve \u00e7ekme hareketi ile sentromerler par\u00e7alan\u0131r.
\n2-Birbirinden ayr\u0131lan karde\u015f kromatidler z\u0131t kutuplara gider<\/p>\n

d)Telofaz-II <\/strong>
\n1-Kutuplara \u00e7ekilen kromatidler helixlerini \u00e7\u00f6zerek kromatin iplik haline ge\u00e7erler
\n2-Nucleus zar\u0131 olu\u015fur.
\n3-\u0130\u011f iplikleri kaybolur
\n4-Sitokinezle iki toplam d\u00f6rt h\u00fccre olu\u015fur.
\n5-Olu\u015fan h\u00fccrelerde ana h\u00fccrenin yar\u0131s\u0131 kadar kromozom dolay\u0131s\u0131yla DNA vard\u0131r
\n6-Olu\u015fan h\u00fccrelerdeki kal\u0131tsal materyal hem profaz-1 de ger\u00e7ekle\u015fen krossing-over hemde metafaz-1 deki homolog kromozomlar\u0131n diziliminin rasgele olmas\u0131ndan dolay\u0131 farkl\u0131d\u0131r
\n7-Olu\u015fan h\u00fccreler erkekte spermatid, di\u015filerde ise oosit\u00a0 denir<\/p>\n

Mayoz b\u00f6l\u00fcnme<\/strong> birbirini takip eden evrelerden olu\u015fur. Evrelerin ger\u00e7ekle\u015fmesi s\u0131ras\u0131nda kromozomlar aras\u0131nda par\u00e7a de\u011fi\u015fimi meydana gelir. Par\u00e7a de\u011fi\u015fimi ile b\u00f6l\u00fcnme u\u011frayan canl\u0131 t\u00fcr\u00fcnde \u00e7e\u015fitlilik sa\u011flanm\u0131\u015f olur<\/strong>. Mitoz ve mayoz b\u00f6l\u00fcnme aras\u0131ndaki farklar<\/strong>
\n\"mitoz<\/a><\/p>\n","protected":false},"excerpt":{"rendered":"

Mayoz b\u00f6l\u00fcnme s\u0131ras\u0131nda kal\u0131tsal \u00e7e\u015fitlili\u011fe neden olan olay, \u00a0mitoz b\u00f6l\u00fcnme kal\u0131tsal \u00e7e\u015fitlilik sa\u011flar m\u0131,\u00a0mayoz b\u00f6l\u00fcnme kal\u0131tsal \u00e7e\u015fitlilik E\u015feyli \u00dcreme ve Kal\u0131tsal Varyasyon Yery\u00fcz\u00fcnde ya\u015fayan ayn\u0131 t\u00fcre ait bireyler birbirlerine benzemelerine ra\u011fmen baz\u0131 farkl\u0131l\u0131klara da sahiptirler. E\u011fer bu farkl\u0131l\u0131klar genler taraf\u0131ndan aktar\u0131l\u0131yorsa kal\u0131tsal varyasyon olarak adland\u0131r\u0131l\u0131r. E\u015feyli \u00fcreme baz\u0131 mekanizmalarla kal\u0131tsal varyasyonlar\u0131n ortaya \u00e7\u0131kmas\u0131nda rol oynar. … Devam\u0131n\u0131 oku…<\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[44],"tags":[],"_links":{"self":[{"href":"https:\/\/www.sorubak.com\/blog\/wp-json\/wp\/v2\/posts\/60740"}],"collection":[{"href":"https:\/\/www.sorubak.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.sorubak.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.sorubak.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.sorubak.com\/blog\/wp-json\/wp\/v2\/comments?post=60740"}],"version-history":[{"count":0,"href":"https:\/\/www.sorubak.com\/blog\/wp-json\/wp\/v2\/posts\/60740\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.sorubak.com\/blog\/wp-json\/wp\/v2\/media?parent=60740"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.sorubak.com\/blog\/wp-json\/wp\/v2\/categories?post=60740"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.sorubak.com\/blog\/wp-json\/wp\/v2\/tags?post=60740"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}