Menene homozygote a cikin kwayoyin halitta? Hanyoyin ilimi da misalai

A cikin kwayoyin halitta, kamar sauran kimiyya, akwai wasu ƙayyadaddun kalmomin da aka tsara don bayyana fassarar mahimmanci. Komawa a makaranta, yawancinmu sun ji maganganu irin su rinjaye, ƙwaƙwalwa, gwiwar, samfurin, homozygosity da heterozygosity, amma basu fahimci abin da ke bayan su ba. Za mu bincika yadda za a yi amfani da shi, abin da ya bambanta da heterozygote da kuma irin rawar da dukkanin jinsin suke takawa a cikin tsari.

Wasu jinsin jama'a

Don amsa wannan tambaya, menene haɓaka, bari mu tuna da gwaje-gwaje na Gregor Mendel. Yayin da yake wucewa daban-daban don canza launin 'ya'yan itatuwa da siffar tsire-tsire, sai ya yanke shawarar cewa sakamakon hayewar shuka ya gaji bayanan kwayoyin daga "kakanninsa". Kodayake manufar "jinsin" bai kasance ba, to, Mendel ya iya kwatanta ainihin ma'anar gadon haruffa. Daga dokokin da Mendel ya gano a tsakiyar karni na sha tara, wannan sanarwa, daga bisani ya kira "tsinkayyar tsarkakakkun kayan kwalliya," ya ce: "A yayin da aka samu kwaskwarima, daya daga cikin nau'o'i guda biyu da ke da alhakin wannan fasalin ya shiga cikinsa." Wato, daga kowannensu iyaye muna samun nau'in guda ɗaya wanda ke da alhakin wani alamar - girma, launin gashi, launi na ido, siffar hanci, fata sautin.

Dukkanin kwayoyin halitta na iya zama rinjaye ko raguwa. Wannan ya kawo mana kusa da kayyade abin da homozygote yake. Dukkan iyayengiji suna iya rufewa don kada ya bayyana kanta a cikin phenotype. Idan a cikin jinsin da dukkanin kwayoyin halittu ke da mahimmanci ko rinjaye, to wannan shine kwayoyin homozygous.

Irin homozygotes

Daga dukan abubuwan da ke sama, yana yiwuwa a amsa wannan tambaya, menene homozygote: tantanin halitta wanda dukkanin jinsin da ke da alhakin wasu alamu sun kasance iri ɗaya. Dukkan kwayoyin halitta suna samuwa a cikin chromosomes homologous kuma a cikin yanayin homozygotes na iya zama ko dai (aa) ko rinjaye (AA). Idan mutum daya ya fi rinjaye, kuma ɗayan ba, to, shi ne heterozygote (Aa). A cikin akwati inda kwayar halittar kwayar halitta ta kasance tsaura, yana da mahimmanci ne idan AA ya fi rinjaye, tun da yake yana dauke da alhakin da ke da alhakin rinjaye.

Tsarin Hanya

Lokacin da aka haɗu da homozygotes guda biyu (maimaitawa ko rinjaye), an kafa hotunan takalma.

Alal misali, akwai furanni guda biyu na rhododendron tare da jinsin bb. Bayan sun haye, zamu sami furanni mai tsabta tare da wannan jinsin.

Hakanan zaka iya ba da misali tare da launi na idanu. Idan iyaye biyu suna da idanu masu launin ruwan kasa kuma suna homozygous don wannan alamar, to, jigon su shine AA. Sa'an nan duk yara zasu sami idanu launin ruwan kasa.

Duk da haka, ƙetare homozygotes baya koyaushe haifar da homozygous ga kowane alama na kwayoyin. Alal misali, ƙetare ja (DD) da kuma farin (dd) zai iya haifar da samin launin ruwan hoda mai launin ruwan hoda. Carnation mai duhu, da launi guda biyu, misali ne wanda bai dace ba. A cikin waɗannan lokuta, tsire-tsire masu tsire-tsire za su kasance heterozygous tare da Dd genotype.

Misalan homozygotes

Akwai misalai da yawa na homozygotes a yanayin. White tulips, carnations, rhododendrons duk misalin misalai ne.

A cikin 'yan Adam, sakamakon sakamakon hulɗar jinsi, kwayoyin homozygous, ko dai fata mai haske, idanu mai launin shuɗi, gashi mai launin gashi ko kuma makanta mai duhu, an kafa su.

Har ila yau akwai lokuta da yawa ana samuwa, amma saboda karfin alamomin da aka yi wa masoya, wanda ba zai iya fada a yanzu ko mutum ne mai ɗauka ba. Yawancin kwayoyin da ke da alhakin cututtuka na kwayoyin halitta suna haifar da maye gurbin maye gurbi kuma suna kwance, don haka suna nuna ne kawai idan chromosomes na homologus ba su da wata kamala mai mahimmanci.