{"id":869,"date":"2020-03-24T11:05:34","date_gmt":"2020-03-24T11:05:34","guid":{"rendered":"https:\/\/uni.hi.is\/apalsson\/?p=869"},"modified":"2020-03-24T11:06:19","modified_gmt":"2020-03-24T11:06:19","slug":"icelandic-stokkbreytast-veirur-hradar-en-floknar-lifverur-2","status":"publish","type":"post","link":"https:\/\/uni.hi.is\/apalsson\/IS\/2020\/03\/24\/icelandic-stokkbreytast-veirur-hradar-en-floknar-lifverur-2\/","title":{"rendered":"St\u00f6kkbreytast veirur hra\u00f0ar en fl\u00f3knar l\u00edfverur?"},"content":{"rendered":"

\u00d6ll spurningin hlj\u00f3\u00f0a\u00f0i svona:<\/p>\n

Eru st\u00f6kkbreytingar hra\u00f0ari hj\u00e1 veirum sem hafa f\u00e1 gen, en hj\u00e1 fl\u00f3knari l\u00edfverum me\u00f0 fleiri gen?<\/p><\/blockquote>\n

Erf\u00f0aefni flytur uppl\u00fdsingar um byggingu og eiginleika l\u00edfvera milli kynsl\u00f3\u00f0a. Mikill munur er \u00e1 st\u00e6r\u00f0 erf\u00f0amengja \u00f3l\u00edkra l\u00edfvera og forma. Laukar hafa 30 milljar\u00f0a basa \u00ed hverri frumu og menn um 6,5 milljar\u00f0a. \u00c1vaxtaflugur<\/a> hafa hins vegar a\u00f0eins 360 millj\u00f3nir basa og hver k\u00f3l\u00edbakter\u00eda er me\u00f0 um 5 millj\u00f3nir basa.<\/span>[1]<\/a><\/sup> Veirur<\/a> eru me\u00f0 mun minni erf\u00f0amengi, fr\u00e1 r\u00famlega \u00fe\u00fasund b\u00f6sum upp \u00ed hundru\u00f0i \u00fe\u00fasunda e\u00f0a jafnvel r\u00famlega millj\u00f3n basa. Svo eru \u00fea\u00f0 veirungarnir (e. viroids), a\u00f0eins nokkur hundru\u00f0 basa l\u00f6ng fyrirb\u00e6ri sem valda me\u00f0al annars sumum pl\u00f6ntusj\u00fakd\u00f3mum og lifrarb\u00f3lgu<\/a> af ger\u00f0 D. St\u00f6kkbreytihra\u00f0i erf\u00f0aefnis er \u00f3l\u00edkur milli h\u00f3pa l\u00edfvera. Hann er m\u00e6ldur \u00ed fj\u00f6lda st\u00f6kkbreytinga <\/a> \u00e1 hvern basa \u00ed erf\u00f0amenginu \u00ed hverri kynsl\u00f3\u00f0. St\u00f6kkbreytihra\u00f0i \u00ed erf\u00f0amengi mannsins er um 7,0 til 8,9 \u00d7 10-9<\/sup>, en a\u00f0eins l\u00e6gri \u00ed erf\u00f0amengi \u00e1vaxtaflugna, e\u00f0a 5,10 til 5,90 \u00d7 10-9<\/sup>. Samanbur\u00f0ur s\u00fdnir a\u00f0 st\u00f6kkbreytihra\u00f0inn er \u00ed \u00f6fugu hlutfalli vi\u00f0 st\u00e6r\u00f0 erf\u00f0amengja. \u00deannig a\u00f0 \u00ed minni erf\u00f0amengjum er h\u00e6rri st\u00f6kkbreytihra\u00f0i. Svari\u00f0 vi\u00f0 spurningunni er \u00fev\u00ed j\u00e1, einfaldar verur eru me\u00f0 h\u00e6rri st\u00f6kkbreytit\u00ed\u00f0ni en fl\u00f3knari l\u00edfverur.<\/span>[2]<\/a><\/sup><\/p>\n

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St\u00f6kkbreytihra\u00f0i er mj\u00f6g \u00f3l\u00edkur milli h\u00f3pa og s\u00fdnir neikv\u00e6tt samband vi\u00f0 st\u00e6r\u00f0 erf\u00f0amengja. \u00c1 myndinni sj\u00e1st \u00f3l\u00edkar veirur og l\u00edfverur. Fr\u00e1 vinstri, veirungur, s\u00ed\u00f0an \u00ferj\u00e1r \u00f3l\u00edkar ger\u00f0ir veira, bakter\u00edur og loks m\u00fas.<\/p>\n<\/div>\n<\/div>\n

\u00c1st\u00e6\u00f0an fyrir muninum er fj\u00f6l\u00fe\u00e6tt. D\u00fdr, pl\u00f6ntur, sveppir og \u00f6rverur nota DNA sem erf\u00f0aefni. Veirur nota anna\u00f0 hvort DNA e\u00f0a RNA<\/a> sem erf\u00f0aefni. DNA og RNA hafa mismunandi st\u00f6kkbreytihra\u00f0a. \u00cd fyrsta lagi er RNA \u00f3st\u00f6\u00f0ugari kjarns\u00fdra en DNA, vegna efnafr\u00e6\u00f0ilegrar byggingar ke\u00f0junnar. \u00cd \u00f6\u00f0ru lagi er DNA yfirleitt \u00e1 tv\u00ed\u00fe\u00e1tta formi \u00ed l\u00edfverum<\/span>[3]<\/a><\/sup> \u00e1 me\u00f0an erf\u00f0aefni sumra veira er \u00e1 eins\u00fe\u00e1tta formi. Eins\u00fe\u00e1tta kjarns\u00fdrur eru berskjalda\u00f0ri fyrir ytri \u00e1hrifum. Aflei\u00f0ingin er munur \u00e1 st\u00f6kkbreytit\u00ed\u00f0ni milli fl\u00f3kinna l\u00edfvera og einfaldari forma, til a\u00f0 mynda veira.<\/p>\n

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Samanbur\u00f0ur \u00e1 tv\u00ed\u00fe\u00e1tta DNA og ein\u00fe\u00e1tta RNA. RNA er eins\u00fe\u00e1tta kjarns\u00fdra en \u00fe\u00e6r eru berskjalda\u00f0ri fyrir ytri \u00e1hrifum.<\/p>\n<\/div>\n<\/div>\n

Samantekt:<\/h3>\n