Mendel dokokin: allele - shi ne tushen gādo

Gaskiyar cewa duk rayayyun kwayoyin halitta, daga amoeba da kuma kawo karshen tare da jinsunan mutane, da salon salula tsarin, sananne ne. Duk da haka, ba kowa da kowa yake tunani game da yadda bayyanar sabon halittu gada wasu siffofin na yadda dokokin dabi'a. Saboda haka watakila yana da lokaci zuwa Brush up a manta daga makaranta ilmin halitta kayan yau da kullum na halittar jini, mafi muhimmanci ga juyin halitta daga kimiyya?

Ma'ana genes

A zuciya na rayayyan tantanin halitta ne kayyade abu - da nucleic acid kunshi maimaita nucleotide, wanda, bi da bi, ya gabatar da Naira Miliyan Xari da nitrogenous tushe, mai phosphate kungiyar da kuma wani biyar-carbon sugar, ribose ko deoxyribose. Irin wannan jerin ne na musamman, saboda a duniya da kuma ba da biyu ne daidai m halittu masu rai. Duk da haka, da sa kwayoyin halitta ba bazuwar, kuma shi ke daga uwar cell (a cikin kwayoyin da asexual irin haifuwa) ko iyaye biyu (tare da jima'i irin). A cikin hali na mutane da yawa dabbobi karshe ra'ayoyi a kayyade kayan auku a lokacin saboda da samuwar wani zygote fe daga namiji da mace gametes. A nan gaba, wannan ya kafa shirye-shirye da kuma ci gaban duk kyallen takarda, gabobin, external fasali da kuma partially har ma da matakin na gaba lafiya.

key sharuddan

Zai yiwu mafi muhimmanci Concepts halittar jini a matsayin kimiyya ne gadar hali da bambancin. Godiya ga farko sabon abu daga dukkan halittu ci gaba da jinsunan da kuma goyon bayan da al'ummar duniya, da kuma na biyu taimaka wajen bullo ta ƙara sabon fasali da kuma kawar da sun rasa dacewar. Na bude shi duka kuma aza harsashin ginin halittar jini Gregor Mendel, wani Austria botanist kuma masanin hallitu ne, wanda ya rayu kuma yi aiki domin amfanin kimiyya a biyu da rabi na XIX karni. The dokokin ka'idar gadar hali, ya buɗe ta ingantaccen bincike da gwaje-gwajen a kan shuke-shuke. A musamman, shi ne aka fi amfani da shi ne Peas, domin shi ne sauki rarrabe allele. Wannan ra'ayi ne da madadin alama, cewa ne na musamman jerin nucleotides, wanda ya bada daya daga cikin biyu bambance-bambancen karatu na bayyanar wani sifa. Alal misali, ja ko fari furanni, dogon ko short wutsiya, da sauransu. Duk da haka, daga gare su akwai bambance da kuma sauran muhimman sharuddan.

Mendel ta farko dokar

Rinjaye (overriding, rinjaye) da kuma recessive allele (repressed, mai rauni) - biyu a halayen da tasiri juna da kuma suna bayyana ta wasu sharudda ba, amma a maimakon haka, a kan Mendel ta dokokin. Saboda haka, na farko na wanda ya furta cewa duk hybrids samar a cikin ƙarni na farko, zai kawo daya kawai fasalin samu daga iyayentaka kwayoyin da m daga gare su. Alal misali, idan da rinjaye allele - mai ja flower launi da kuma recessive - fari, sa'an nan da mararraba na biyu shuke-shuke da wadannan cututtuka samu hybrids da kawai ja furanni.

Wannan dokar da yake da inganci idan iyaye tsire-tsire masu tsabta Lines, cewa shi ne homozygous. Duk da haka, ya kamata mu nuna cewa a farko doka mai kananan gyara - kodominirovanie ãyõyi, ko bai cika ba dominance. Wannan mulki ya ce ba dukkan siffofin ne tsananin tasiri a kan rinjaye wasu, da kuma na iya faruwa lokaci guda. Alal misali, iyayentaka jinsunan da ja da fari furanni tsara tare da ruwan hoda launi na petals bayyana. Wannan shi ne domin ko da yake wani rinjaye allele - shi ne ja, amma shi ba shi da wani cikakken tasiri a kan recessive fari. Sabili da haka, akwai wani na uku view of launi hadawa saboda da halaye.

Na biyu dokar Mendel

Gaskiyar cewa kowane gene da aka nuna ta biyu m haruffa na Latin haruffa, misali "Aa". A wannan yanayin, da take ne mai rinjaye hali, da kuma kananan - recessive. Saboda haka, homozygous alleles aka kaddamarda "aa" ko "AA", kamar yadda suke da wannan alamar, da kuma heterozygous - "Aa", watau su ne da tsaba na biyu parental halaye.

A gaskiya, a kan wannan kuma da wadannan dokar Mendel da aka gina - a tsagawa fasali. Domin wannan kwarewa, ya haye biyu shuke-shuke da heterozygous alleles samu a cikin ƙarni na farko na farko kwarewa. Saboda haka, shi ya na bayyana biyu ãyõyi. Alal misali, a rinjaye allele - shi ne m furanni, da kuma wani recessive - fari, su genotype "AA" da "AA". By tsallaka da su a cikin na farko gwaji, ya samu mai shuka da genotype "Aa" da "Aa", da cewa shi ne heterozygous. Kuma a shiri na biyu ƙarni, cewa shi ne, "Aa" + "Aa", mu samu "AA", "Aa", "Aa" da "aa". Wannan shi ne, shi ya bayyana a matsayin shunayya, da fararen furanni, da kuma, a cikin wani rabo na 3: 1.

The uku dokar

Kuma na karshe dokar Mendel - mai zaman kanta gādon biyu rinjaye halaye. La'akari da shi da mafi sauki a kan misali da wani giciye tsakanin daban-daban irin Peas - tare da m rawaya da kore wrinkled tsaba, inda rinjaye allele - shi ne santsi da kuma rawaya.

A sakamakon haka, muna samun daban-daban haduwa da wadannan cututtuka, da cewa shi ne kama da iyaye, kuma a bãyansu - wrinkled rawaya da kore tsaba santsi. A wannan yanayin, da irin zane na Peas ba zai dogara ne a kan su launi. Saboda haka, wa'yannan biyu siffofin za a gaji ba tare da shafi juna.