Ngā Whakawhitinga Tauira-rua: Te Tūhura i ngā Kaupapa Taketake o te Ira Mendelian
Ko tētahi o ngā ariā tino taketake o te ira ko te whakawhiti ira-rua. Nā Gregor Mendel tēnei ariā i whakatakoto tuatahi, he mōneka me te kaipūtaiao o te rautau 19 e mōhiotia ana ko te matua o te ira. I roto i āna whakamātautau ki ngā tipu pī, i angitu a Mendel ki te hura i ngā tauira taketake o te tuku iho kua waiho hei tūāpapa mō te ira-rua o ēnei rā. Ka ruku hohonu ake tēnei tuhinga ki te whakawhiti ira-rua, ōna mātāpono taketake, me ōna tono me tōna hiranga i roto i ngā momo mara pūtaiao.
Te Mārama ki ngā Whakawhitinga Dihybrid
Ko te whakawhiti ira-rua he whakawhiti i waenganui i ngā tāngata e rua he heterozygous mō ngā takirua āhuatanga rerekē e rua. He rerekē tēnei i te whakawhiti ira-rua kotahi, e tātarihia ana te āhuatanga kotahi. Hei tauira, i roto i ngā tipu pī, me tirotiro pea te tukunga iho o ngā āhuatanga e rua i te wā kotahi, pērā i te tae o te purapura (kōwhai, kakariki rānei) me te āhua o te purapura (porowhita, miro rānei).
Hei mārama ki ngā whakawhiti ranu-rua, me mārama tātou ki ngā ture e rua i whakatakotoria e Mendel:
1. Ture Wehewehe: He takirua iraira kei ia tangata mō ia āhuatanga, ā, ka wehea ēnei iraira i te wā e hangaia ana ngā gamete.
2. Te Ture o te Whakarōpūtanga Motuhake: Ka hono motuhake ngā ira mō ngā āhuatanga rerekē i te wā e hangaia ana ngā gamete. Ko te tikanga o tēnei, kāore te tukunga iho o tētahi āhuatanga e pā ki te tukunga iho o tētahi atu āhuatanga.
Ngā hikoinga i te whitinga ranu-rua
Kia whakaarohia tētahi tauira matarohia o te whakawhiti ranu-rua i mahia e Mendel: te mātakitaki i te tae me te āhua o ngā purapura i roto i ngā pī.
1. Te Tautuhi ira-ira a ngā Mātua: He ira-kē ngā mātua mō ngā āhuatanga e rua, hei tauira, YyRr (Y = kōwhai, y = kakariki, R = porowhita, r = kita).
2. Te Hanganga o ngā Gamete: Ka taea e ngā iraira o ngā āhuatanga rerekē e rua te hono hei hanga i ngā gamete i roto i ngā huinga e whai ake nei: YR, Yr, yR, yr. He ōrite te auau o ia huinga e puta ana i runga i te ture o te whakarōpūtanga motuhake.
3. Te Hanganga o te Tūtohi Punnett: Mā te whakamahi i te tūtohi Punnett, ka taea e tātou te matapae i ngā huinga ira tangata pea o ngā uri. I tēnei wā, ka whakamahia he tūtohi Punnett 4×4 hei whakarārangi i ngā huinga gamete katoa e taea ana.
4. Te Whakatau i te Ōwehenga Āhuatanga: Mai i ēnei huinga, ka taea e tātou te whakatau i ngā āhuatanga ka puta. I roto i te take a Mendel, ko te ōwehenga āhuatanga i whiwhihia ko 9:3:3:1 mō te huinga katoa (9 porowhita kōwhai, 3 porowhita kakariki, 3 kōwhai kua miro, 1 kakariki kua miro).
Te Hiranga me te Whakamahinga
Ehara i te mea he mea taketake noa iho te ariā o ngā whakawhiti ranu-rua i roto i te koiora, engari he whānui hoki ngā tono o te ao tūturu i roto i ngā mara maha:
1. Te Whakatipu Tipu me te Kararehe
I roto i te ahuwhenua, ka whakamahia ngā mātāpono tuku iho a Mendelian hei whakawhanake i ngā momo tipu me ngā momo kararehe me ngā āhuatanga e hiahiatia ana. Hei tauira, mā te mārama ki te tukunga iho o ētahi āhuatanga, ka taea e ngā kaiwhakatupu kararehe te whiriwhiri i ngā kararehe he āhuatanga whakaputa motuhake hei whakaputa uri pai ake.
2. Ngā Ira Hauora
I roto i te tangata, ka whakamahia ngā mātāpono ōrite i roto i te rangahau i te tukunga iho o ngā mate ira. Ko ētahi mate e whakahaerehia ana e ngā ira maha (polygenic), ā, mā te mārama ki ēnei taunekeneke uaua ka āwhina i te tautuhi me te whakawhanake i te rongoā.
3. Te Hangarau Koiora me te Hangarau Ira
He mea nui te māramatanga hōhonu ki ngā ira taketake, tae atu ki ngā whakawhiti ira-rua, i roto i te hangarau koiora. Mā tēnei ka taea te whakahaere i ngā ira hei hanga i ngā rauropi me ngā āhuatanga e hiahiatia ana, i roto i ngā horopaki hauora me ngā horopaki ahumahi.
4. Rangahau Pūtaiao me te Mātauranga
I roto i ngā rangahau taketake, he mea nui tonu ngā whakawhiti ira-rua hei ako i te tukunga iho ira me ngā taunekeneke allelic. I roto i te mātauranga, ka whakamahia te ariā hei whakaako i ngā ākonga ki ngā kaupapa matua o te ira.
Ngā Here me te Uauatanga
Heoi anō, he herenga kei roto i tēnei mātāpono māmā o te whakarōpūtanga motuhake. Kāore ngā ira katoa e tukuna motuhaketia ana; kei te tata tonu ētahi ira tetahi ki tetahi i runga i te ira kotahi, ā, ka taea te tuku tahi, he āhuatanga e mōhiotia ana ko te hononga ira. Ka tāpirihia e tēnei tētahi atu paparanga uaua ki ngā rangahau ira me whai whakaaro ki roto i ngā tātaritanga atu.
Ngā Whanaketanga Hou
I ngā tekau tau tata nei, kua hohonu ake te māramatanga o ngā hangarau ira, pērā i te raupapatanga ira me ngā taputapu tātari ira, ki tua atu i ngā mātāpono taketake a Mendel. Heoi anō, kei te whai tikanga tonu ngā mātāpono taketake a Mendel, e pā ana ki ngā whakawhiti ira-rua, ā, he maha ngā wā ka noho hei tūāpapa mō ngā kitenga hou uaua ake.
Whakamutunga
Ko ngā whakawhiti ira-rua he pou matua o te ira tawhito. Mā te mārama ki te tukunga iho o ngā takirua āhuatanga e rua ka kitea he māramatanga hohonu ake ki ngā tikanga taketake o te tukunga iho. Nā te whānui o ngā whakamahinga i roto i te ahuwhenua, te rongoā, me te hangarau koiora, ehara i te mea ka whakarei ake i ō tātou mōhiotanga taketake mō te koiora anake ēnei tikanga, engari ka tukuna hoki he otinga mahi ki ngā wero o te ao tūturu. Ahakoa ka ara ake ngā wero hou he nui ake te uaua, ko ngā kaupapa taketake o te ira Mendelian he taahiraa tuatahi nui tonu mō te hunga e tūhura ana i te ao whakamīharo o te ira.
