Poʻomanaʻo: Laʻana o nā nīnau kūkākūkā Dihybrid Cross
Pengantar
ʻO ka huaʻōlelo "dihybrid" e pili ana i kahi keʻa ma waena o ʻelua mau kānaka i ʻokoʻa i ʻelua mau ʻano a i ʻole nā genes hoihoi, me kēlā me kēia ʻano he ʻelua mau alleles hiki. ʻO nā keʻa Dihybrid kahi manaʻo nui i ka genetics Mendelian, e kōkua ana iā mākou e hoʻomaopopo pehea e hoʻoili ʻia ai nā ʻano ma o nā hanauna. E ʻeli hohonu kēia ʻatikala i nā keʻa dihybrid ma ka hāʻawi ʻana i nā laʻana a me nā kūkākūkā.
Ke Hoʻomaopopo ʻana i nā Keʻa Dihybrid
Ke nānā nei kahi keʻa dihybrid i ʻelua mau ʻano like ʻole. Hoʻomalu ʻia kēlā me kēia ʻano e kahi pālua o nā alleles i hiki ke lilo i dominant a recessive paha. ʻO kahi keʻa dihybrid e pili ana i nā mākua heterozygous no ʻelua mau ʻano like ʻole a nānā i ka hoʻolaha ʻana o kēlā mau alleles i kā lākou mau keiki.
Nā Kumumanaʻo Kumu o nā Kānāwai o Mendel
1. Ke Kānāwai o ka Hoʻokaʻawale ʻana: E hoʻokaʻawale a hoʻokaʻawale paha nā Alleles no kahi ʻano a i ʻole gene i ka wā o ka hoʻokumu ʻana o ka gamete, i loaʻa i kēlā me kēia gamete hoʻokahi wale nō allele mai kēlā me kēia hui allele.
2. Ke Kānāwai o ka Hoʻohui Kūʻokoʻa: E hoʻoilina kūʻokoʻa ʻia nā alleles o nā genes like ʻole kekahi i kekahi, ʻo ia hoʻi, ʻaʻole pili ka hoʻolaha ʻana o kekahi allele i ka hoʻolaha ʻana o kekahi allele - ke ʻole ka pili kino ʻana o nā genes ma ka chromosome like.
ʻAno Genotype a me ke ʻano Phenotype
I loko o kahi keʻa dihybrid, hana maʻamau mākou me ʻehā mau hui gamete hiki, ʻoiai inā he heterozygous nā mākua no nā ʻano ʻelua. ʻO ke ʻano kēia ke hana nei mākou me kahi hanana paʻakikī o nā pilina allelic ma mua o kahi keʻa monohybrid hoʻokahi, kahi e kālele ana i hoʻokahi gene wale nō.
Formula no ka hoʻoholo ʻana i ka helu o nā Gametes
Inā ʻo AaBb ke kanaka, a laila hiki iā mākou ke hoʻohana i ke kānāwai o ka hoʻohui kūʻokoʻa e hoʻoholo ai i ka helu o nā gametes ma ka hoʻonui ʻana i ka hiki ke loaʻa o kēlā me kēia hui allele, e loaʻa ana ka hopena 2 x 2 = 4 mau ʻano gametes like ʻole, ʻo ia hoʻi ʻo AB, Ab, aB, a me ab.
Laʻana o nā nīnau kea Dihybrid
Nīnau 1: Ke hoʻohui ʻana ma waena o ʻelua mau mea kanu pī
Loaʻa i nā mea kanu pī nā alleles poepoe (R) a me nā wrinkled (r), a he melemele (Y) a ʻōmaʻomaʻo paha (y) ke kala. ʻElua mau mea kanu, kēlā me kēia heterozygous no nā ʻano ʻelua (RrYy), ua hui ʻia. He aha nā lakio phenotypic hiki?
Nā ʻanuʻu hoʻonā:
1. E hoʻoholo i nā Gametes mai nā Mākua: No ka mea he heterozygous nā mea ʻelua (RrYy), hiki iā mākou ke loaʻa ʻehā ʻano gametes mai kēlā me kēia, ʻo ia hoʻi: RY, Ry, rY, ry.
2. Ke hoʻohana nei iā Punnett Square: Ma ke komo ʻana i nā gametes āpau i loko o kahi 4 × 4 Punnett Square, hiki iā mākou ke hoʻoholo i nā genotypes hiki o ka hua.
3. Hoʻokumu i ka Genotype a me ka Phenotype:
– ʻO ke Genotype Round-Yellow (R_Y_) ʻo RY a me nā mea ʻē aʻe e hoʻohui pū ana.
– ʻO ka Phenotype Genotype Round-Green (R_yy) ʻo Ry a me ka hui pū ʻana e hiki ke hana i kēia.
– ʻO ke ʻano genotype phenotype Wrinkled-Yellow (rrY_) ʻo rY a me nā hui pū ʻana e pili ana.
– ʻO ke ʻano o ka Wrinkled-Green (rryy) Genotype Phenotype ʻo ia ʻo ry a me nā hui pū ʻana e pili pū ana.
4. E helu i ka alapine (frequency) o ka Phenotype:
– E helu i nā pahu ʻāpana nui a pau e wānana i ka alapine (frequency) phenotypic.
– I ka hopena, loaʻa iā ʻoe kahi lakio Mendelian maʻamau no ke keʻa dihybrid: 9:3:3:1.
No laila, ʻo ka lakio phenotypic i loaʻa mai kēia keʻa he 9 Poepoe-Melemele: 3 Poepoe-ʻŌmaʻomaʻo: 3 Wrinkled-Melemele: 1 Wrinkled-ʻŌmaʻomaʻo.
Nīnau 2: Ke hoʻohui ʻana i nā hua kanu o nā mea kanu ʻē aʻe
He ʻulaʻula nā pua o kahi mea kanu (A) e noho aliʻi ana ma luna o ke keʻokeʻo (a) a ʻo ke kiʻekiʻe o ka mea kanu (T) e noho aliʻi ana ma luna o ka pōkole (t). Inā ua hui ʻia kahi mea kanu pili ʻo AaTt me kahi mea kanu aatt, he aha ka hopena o ka F1?
Nā ʻanuʻu hoʻonā:
1. E wehewehe i nā Gametes Makua:
– ʻO ka gamete mea kanu mua (AaTt) ʻo AT, At, aT, a i ʻole at.
– Aia ka lua o ka gamete mea kanu (aatt) ma.
2. E hana i kahi kiʻikuhi kea:
– E hoʻohui i nā gametes hiki ke loaʻa mai kēlā me kēia makua me ka hoʻohana ʻana i ka Punnett Square 4 × 1.
- Pono ʻoe e loiloi i nā hui pū ʻana o nā hopena.
3. E hoʻoholo i nā hui pū ʻana o Genotype a me Phenotype:
– E hoʻoholo i ka lakio phenotype me:
– AT-: ʻUlaʻula-Kiʻekiʻe
– aaT-: Keʻokeʻo-Kiʻekiʻe
– A-tt: ʻUlaʻula-Pōkole
– aatt: Keʻokeʻo-Pōkole
4. E helu i ka Phenotypic a me Genotypic Distribution:
– E ʻike i ka lakio ma muli o nā hui pū ʻana o ka genotype.
ʻO ka hopena he 1 ʻUlaʻula-Loaʻa: 1 ʻUlaʻula-Pōkole: 1 Keʻokeʻo-Loaʻa: 1 Keʻokeʻo-Pōkole.
Ka hopena
Hāʻawi nā keʻa Dihybrid i nā ʻike hohonu i ke ʻano o ka hoʻoilina ʻana a me ka hōʻike ʻana o nā ʻano genes like ʻole i nā keiki. Ma ka hoʻomaopopo ʻana i nā kānāwai o Mendel no ka hoʻokaʻawale ʻana a me ka hoʻohui kūʻokoʻa, hiki iā mākou ke manaʻo i nā hopena o nā keʻa like ʻole. ʻO ka hoʻomaʻamaʻa ʻana me nā pilikia hoʻohālike, e like me nā mea i hōʻike ʻia ma luna, he kī ia i ka hoʻomaopopo kikoʻī ʻana i kēia mau manaʻo a me kā lākou noi ʻana i nā ʻoiaʻiʻo o ka genetics mea kanu a holoholona paha. ʻOiaʻiʻo, ʻo kēia wale nō ka hoʻomaka ʻana o kahi ʻimi paʻakikī o ka loli genetic a me nā pilina ma waena o nā genes i loko o nā meaola.
