Taitara: Tauira o ngā Pātai Kōrero mō te Whakawhitiwhitinga Ranu-rua
Pengantar
Ko te kupu "dihybrid" e pā ana ki te whakawhiti i waenga i ngā tāngata e rua he rerekē ngā āhuatanga e rua, ngā ira rānei e hiahiatia ana, ā, e rua pea ngā ira o ia āhuatanga. Ko ngā whakawhiti dihybrid he ariā taketake i roto i te ira Mendelian, e āwhina ana i a tātou ki te mārama ki te tuku iho i ngā āhuatanga i roto i ngā whakatipuranga. Ka ruku hohonu ake tēnei tuhinga ki ngā whakawhiti dihybrid mā te whakarato tauira me ngā kōrero.
Te Mārama ki ngā Whakawhitinga Dihybrid
Ko te whakawhiti ira-rua e aro ana ki ngā āhuatanga e rua. Ko ia āhuatanga e whakahaerehia ana e tētahi takirua ira-rua, ka taea te noho hei ira-matua, hei ira-heke rānei. Ko te whakawhiti ira-rua e uru ana ki ngā mātua he ira-rua mō ngā āhuatanga e rua, ā, ka tirotirohia te tohatoha o aua ira-rua ki ā rātou uri.
Ngā Mātāpono Taketake o ngā Ture a Mendel
1. Ture Wehewehe: Ka wehea matapōkeretia, ka wehea rānei ngā ira mō tētahi āhuatanga, mō tētahi ira rānei, i te wā e hangaia ana ngā gamete, kia kotahi noa te ira o ia gamete mai i ia takirua ira.
2. Te Ture o te Whakarōpūtanga Motuhake: Ka tukuna motuhaketia ngā ira o ngā ira rerekē tetahi i tetahi, ko te tikanga kāore te tohatoha o tētahi ira e pā ki te tohatoha o tētahi atu ira – ki te kore ngā ira e hono ā-tinana ana i runga i te ira kotahi.
Hanganga Ira-ira me te Āhua-āhua
I roto i te whakawhiti ira takirua, e whā ngā huinga gamete ka taea te whakamahi, inā koa he heterozygous ngā mātua mō ngā āhuatanga e rua. Ko te tikanga tēnei kei te aro tātou ki tētahi āhuatanga uaua ake o ngā taunekeneke allelic i roto i te whakawhiti ira takirua kotahi, e aro ana ki te ira kotahi anake.
Te Tātai mō te Whakatau i te Tau o ngā Gamete
Mena ko AaBb te tangata takitahi, ka taea e tātou te whakamahi i te ture o te whakarōpūtanga motuhake hei whakatau i te maha o ngā gametes mā te whakarea i te tūponotanga o ia takirua ira, ka puta ko te hua 2 x 2 = 4 ngā momo gametes rerekē, arā, AB, Ab, aB, me ab.
Tauira o ngā Pātai Whakawhitinga Dihybrid
Pātai 1: Te Whakakotahi i waenganui i ngā Tipu Pī e Rua
He porowhita (R) me he miro (r) ngā ira o ngā tipu pī, ā, he kōwhai (Y) he kakariki rānei (y) te tae. E rua ngā tipu, he heterozygous ia mō ngā āhuatanga e rua (RrYy), ka whakawhitia. He aha ngā ōwehenga phenotypic ka taea?
Ngā Hipanga Whakaoti:
1. Whakatauhia ngā Gamete mai i ngā Mātua: Nā te mea he heterozygous ngā mea e rua (RrYy), e whā ngā momo gamete ka taea te tiki mai i ia mea, arā: RY, Ry, rY, ry.
2. Te Whakamahi i te Tapawhā Punnett: Mā te whakauru i ngā pūtau katoa ki roto i te Tapawhā Punnett 4×4, ka taea e tātou te whakatau i ngā momoira pea o te uri.
3. Te Hanga i te Ira-ira me te Ira-āhua:
– Ko te Ira Ira Porowhita-Kōwhai (R_Y_) ko RY me ētahi atu e whakakotahi ana i tēnei.
– Ko te Āhuatanga Ira-Kakariki-Porowhita (R_yy) ko Ry me te huinga ka taea te whakaputa i tēnei.
– Ko te momoira āhua kōwhai-wrinkle (rrY_) ko rY me ōna huinga e haere tahi ana.
– Ko te Āhuatanga Ira Wrinkled-Green (rryy) ko ry me ōna huinga e haere tahi ana.
4. Tātaihia te Auautanga o te Āhuatanga:
– Tatauhia ngā pouaka wāhanga nui katoa hei matapae i te auau o ngā āhuatanga.
– Hei whakamutunga, ka whiwhi koe i te ōwehenga Mendelian matarohia mō te whakawhiti ranu-rua: 9:3:3:1.
Nō reira, ko te ōwehenga āhuahanga i whiwhi mai i tēnei whakawhiti ko 9 Porowhita-Kōwhai: 3 Porowhita-Kākāriki: 3 Kōwhai-Whāiti: 1 Kōwhai-Kākāriki.
Pātai 2: Te Whakakotahi i ngā Kākano o Ētahi Atu Tipu
He whero ngā putiputi o tētahi tipu (A) e kaha ake ana i te mā (a) ā, he kaha ake te teitei o te tipu (T) i te poto (t). Mēnā ka whakawhitia tētahi tipu hoa AaTt ki tētahi tipu aatt, he aha te hua o te F1?
Ngā Hipanga Whakaoti:
1. Whakaahuahia ngā Gamete Matua:
– Ko te gamete tipu tuatahi (AaTt) ko AT, At, aT, at rānei.
– Kei te rua o ngā pūtau tipu (aatt) te gamete.
2. Waihangahia he Kauwhata Whakawhiti:
– Whakakotahitia ngā pūtau pūtau pea mai i ia mātua mā te whakamahi i te Tapawhā Punnett 4×1.
– Me arotake e koe ngā huinga hua.
3. Whakatauhia ngā Huinga Ira-ira me te Āhua-āhua:
– Whakatauhia te ōwehenga āhuahanga tae atu ki:
– AT-: Whero-Teitei
– aaT-: Mā-Teitei
– A-tt: Whero-Poto
– aatt: Pōturi-Mā
4. Tātaihia te Tohatoha Āhuatanga me te Tohatoha Ira Tangata:
– Tāutuhia te ōwehenga i runga i ngā huinga iraira pea.
Ko te hua ko 1 Whero-Teitei: 1 Whero-Poto: 1 Mā-Teitei: 1 Mā-Poto.
Whakamutunga
Mā ngā whakawhiti ira-rua ka kitea he māramatanga hōhonu mō te tuku iho me te whakaatu i ngā ira rerekē i roto i ngā uri. Mā te mārama ki ngā ture wehewehe me te whakarōpū motuhake a Mendel, ka taea e tātou te matapae i ngā putanga o ngā whakawhiti ira rerekē. Ko te mahi me ngā tauira raruraru, pērā i ngā mea kua whakarārangihia i runga ake nei, he mea nui ki te māramatanga taipitopito o ēnei ariā me tō rātou whakamahinga ki ngā āhuatanga tūturu o te ira tipu, kararehe rānei. Ko te tikanga, koinei anake te tīmatanga o tētahi tūhuratanga uaua ake o te rerekētanga ira me ngā taunekeneke i waenga i ngā ira i roto i ngā rauropi.
