Taitara: Ngā Pātai Tauira me te Kōrero mō ngā Whakawhitinga Monoranu
Pendahuluan
Ko te ira tangata he peka o te koiora e ako ana i te tukunga o ngā āhuatanga mai i tētahi whakatipuranga ki tētahi whakatipuranga. Ko tētahi ariā matua o te ira tangata ko te whakawhiti monohybrid, he whakawhiti e whai wāhi ana te takirua o ngā āhuatanga rerekē. He mea whakahihiri, he mea wero hoki, ā, he maha ngā wā ka whakamahia ngā whakawhiti monohybrid hei ako i te taunekeneke a ngā alleles (ngā momo ira) hei whakatau i ngā āhuatanga o tētahi rauropi. I roto i tēnei tuhinga, ka matapakihia e mātou ētahi tauira raruraru me ā rātou matapakinga e pā ana ki ngā whakawhiti monohybrid.
Tauira Pātai 1: Te Whakawhiti i te Pī
Ko tētahi tauira matarohia o te whakawhiti monohybrid ko te rangahau a Gregor Mendel me ngā tipu pī. I tētahi whakamātautau, i whakawhitia e Mendel tētahi tipu pī puawai-papura matua (UU) me tētahi tipu pī puawai-mā (uu).
Pātai: He aha ngā momo āhua me ngā momoira o te uri F1 me te uri F2?
Kōrero:
– Whakatupuranga F1:
I whakawhitia e Mendel tētahi tipu pua-papura (UU) ki tētahi tipu pua-mā (uu). Nā tēnei whakawhiti, ka whiwhi ngā uri F1 katoa i te iraira (Uu) nā te mea i whiwhi rātou i tētahi iraira matua mai i te matua pua-papura me tētahi iraira heke mai i te matua pua-ma. Nā te mea he matua te iraira papura (U), ka whai iraira papura ngā tipu F1 katoa. Nō reira, i roto i te whakatupuranga F1, he iraira papura tō ngā tipu katoa me tētahi iraira heterozygous (Uu).
– Whakatupuranga F2:
Ina whakawhitia ngā tipu F1 (Uu) tetahi ki tetahi, ko te ōwehenga āhuahanga o ngā uri F2 ka puta ko te 3:1, i runga i te tapawhā Punnett. Ko te tohatoha āhuahanga ka puta ko te 1 UU: 2 Uu: 1 uu. Mō te āhuahanga, e 3 o ngā tipu ka whai putiputi papura, ā, kotahi ka whai putiputi mā.
Nō reira, ko te momoira F2 koia ēnei:
– 25% UU (ira matua homozygous)
– 50% Uu (heterozygous)
– 25% uu (ira-ira-ira-rite)
Ko te āhua o te tinana ko:
– 75% ngā putiputi papura (UU me Uu)
– 25% putiputi mā (ūu)
Tauira Pātai 2: Te Whakawhiti Kararehe
Whakaarohia te whakawhiti ira i roto i ngā kiore. Me kī ko te ira mō te huruhuru mangu (B) he kaha ake i te ira mō te huruhuru parauri (b). Mena ka whakawhitia he kiore heterozygous (Bb) ki tētahi kiore homozygous recessive (bb), he aha te āhua me te momoira o ā rāua uri?
Kōrero:
– He ira-kē te kiore tuatahi me te ira-ira (Bb), ā, he ira-kē te kiore tuarua me te ira-ira (bb).
– Mā te whakamahi i te tapawhā Punnett, ka taea e tātou te kite i ngā huinga iraira pea o te uri:
| | P | p |
|—|—-|—-|
| p | Pb | bb |
| p | Pb | bb |
– Ko ngā momoira pea o te uri ko:
– 50% Bb (heterozygous)
– 50% bb (ira-ira-ira-rite)
– Mō te āhua o te tinana:
– 50% o ngā uri ka mangu te huruhuru (Bb)
– 50% ka parauri te huruhuru (bb)
Tauira Pātai 3: Te Whakawhanaungatanga i roto i te Tangata
I roto i te tangata, me kī ko te ira mō ngā maihao noa (N) he kaha ake i te ira mō ngā polydactyly (ngā maihao tāpiri) (n). Mēnā he heterozygous tētahi matua mō tēnei āhuatanga, ā, he homozygous tētahi atu matua mō te recessive, he aha te ōwehenga phenotype-ki-genotype o te uri?
Kōrero:
– Kei ngā mātua heterozygous te iraira (Nn), ā, kei ngā mātua homozygous recessive te iraira (nn).
– Mā te whakamahi i ngā tapawhā Punnett, ka whiwhi tātou:
| | N | n |
|—|—-|—-|
| n | Nn | nn |
| n | Nn | nn |
– Ko te momoira o te uri ko:
– 50% Nn (heterozygous)
– 50% nn (whakahekenga homozygous)
– Ko te āhua o te uri:
– 50% ngā maihao noa (Nn)
– 50% polydactyly (nn)
Ngā tauira:
He taputapu nui ngā whakawhiti monohybrid hei mārama ki ngā mātāpono o te tukunga iho. Mā te whakamahi i ngā mātāpono taketake pēnei i te mana me te hekenga, ka taea e tātou te matapae i te tohatoha o ngā momo āhua me ngā momo ira i ngā whakatupuranga o muri mai. Ko te mea nui ki te mārama ki ngā whakawhiti monohybrid ko te mōhio ki ngā tohu mō ngā ira matua me ngā ira hekenga, me te kaha ki te hanga me te tātari i ngā tapawhā Punnett. Mā te mahi tonu me ngā tauira maha ka whakapakari i tō tātou mōhiotanga ki ngā ira taketake, ka whakarei ake hoki i tō tātou māramatanga ki te tukunga iho o ngā āhuatanga.
