Mutu: Mafunso ndi Kukambirana za Mitanda ya Monohybrid
Pendauluan
Genetics ndi nthambi ya zamoyo yomwe imaphunzira momwe makhalidwe amapatsidwira kuchokera ku mibadwomibadwo kupita ku ina. Lingaliro limodzi lofunika kwambiri mu majini ndi mtanda wa monohybrid, womwe ndi mtanda wokhala ndi makhalidwe awiri osiyana. Mitundu yosiyanasiyana ya monohybrid yosangalatsa komanso yovuta, nthawi zambiri imagwiritsidwa ntchito pophunzira momwe ma alleles (mitundu ya jini) amagwirira ntchito kuti adziwe makhalidwe a chamoyo. M'nkhaniyi, tikambirana zitsanzo zingapo za mavuto ndi kukambirana kwawo pankhani ya mtanda wa monohybrid.
Chitsanzo Funso 1: Kuwoloka Mbeu za Nandolo
Chitsanzo chimodzi chodziwika bwino cha kusakaniza kwa monohybrid ndi kafukufuku wa Gregor Mendel wokhudza zomera za nandolo. Mu kafukufuku wina, Mendel adaphatikiza chomera chachikulu cha nandolo chokhala ndi maluwa ofiirira (UU) ndi chomera cha nandolo chokhala ndi maluwa oyera (uu).
Funso: Kodi mitundu ndi majini a ana a F1 ndi F2 ndi ati?
Kukambirana:
- Mbadwo wa F1:
Mendel adaphatikiza chomera chokhala ndi maluwa ofiirira (UU) ndi chomera chokhala ndi maluwa oyera (uu). Chifukwa cha mtanda uwu, ana onse a F1 adzakhala ndi genotype (Uu) chifukwa adalandira allele imodzi yolamulira kuchokera kwa kholo la maluwa ofiirira ndi allele imodzi yozungulira kuchokera kwa kholo la maluwa oyera. Chifukwa allele yofiirira (U) ndi yolamulira, zomera zonse za F1 zidzakhala ndi phenotype yofiirira. Chifukwa chake, mu m'badwo wa F1, zomera zonse zimakhala ndi phenotype yofiirira yokhala ndi genotype ya heterozygous (Uu).
- Mbadwo wa F2:
Pamene zomera za F1 (Uu) zasakanikirana, ana a F2 omwe amachokera amakhala ndi chiŵerengero cha phenotypic cha 3:1, kutengera sikweya ya Punnett. Kugawa kwa majini komwe kumachitika ndi 1 UU: 2 Uu: 1 uu. Ponena za phenotype, zomera zitatu zidzakhala ndi maluwa ofiirira ndipo chimodzi chidzakhala ndi maluwa oyera.
Chifukwa chake, genotype ya F2 imakhala ndi:
– 25% UU (homozygous yolamulira)
– 50% Uu (heterozygous)
– 25% uu (homozygous recessive)
Mtundu wa phenotype uli ndi:
– 75% maluwa ofiirira (UU ndi Uu)
– 25% maluwa oyera (uu)
Chitsanzo Funso 2: Kuoloka Zinyama
Taganizirani za mtanda wa mbewa. Tiyerekeze kuti allele ya ubweya wakuda (B) ndi yolamulira kuposa allele ya ubweya wa bulauni (b). Ngati mbewa ya heterozygous (Bb) yaphatikizidwa ndi mbewa ya homozygous recessive (bb), kodi mtundu wanji ndi genotype ya ana awo zidzakhala zotani?
Kukambirana:
– Mbewa yoyamba ndi heterozygous yokhala ndi genotype (Bb), ndipo mbewa yachiwiri ndi recessive homozygous yokhala ndi genotype (bb).
– Pogwiritsa ntchito sikweya ya Punnett, titha kuwona kuphatikiza kwa allele komwe kungatheke kwa ana:
| | B | b |
|—|—-|—-|
| b | Bb | bb |
| b | Bb | bb |
– Mitundu ya majini yomwe ingakhalepo ya ana ndi iyi:
– 50% Bb (heterozygous)
– 50% bb (homozygous recessive)
- Ponena za phenotype:
– 50% ya ana adzakhala ndi ubweya wakuda (Bb)
- 50% adzakhala ndi ubweya wofiirira (bb)
Chitsanzo Funso 3: Kubereketsa Mitundu Yosiyanasiyana mwa Anthu
Kwa anthu, tiyerekeze kuti allele ya zala zabwinobwino (N) ndiyo yolamulira allele ya zala zambiri (zala zina) (n). Ngati kholo limodzi ndi la heterozygous chifukwa cha khalidweli ndipo kholo lina ndi la homozygous chifukwa cha recessive, kodi chiŵerengero cha phenotype-to-genotype cha mwana ndi chotani?
Kukambirana:
– Makolo a Heterozygous ali ndi genotype (Nn), ndipo makolo a recessive homozygous ali ndi genotype (nn).
– Pogwiritsa ntchito mabwalo a Punnett, timapeza:
| | N | n |
|—|—-|—-|
| n | Nn | nn |
| n | Nn | nn |
– Mtundu wa mbewu ndi:
– 50% Nn (heterozygous)
– 50% nn (homozygous recessive)
– Mtundu wa mbewu ndi:
– 50% zala zabwinobwino (Nn)
- 50% polydactyly (nn)
Pomaliza:
Mitanda ya monohybrid ndi chida chofunikira kwambiri pomvetsetsa mfundo za cholowa. Pogwiritsa ntchito mfundo zoyambira monga ulamuliro ndi kubwerezabwereza, titha kuneneratu kufalikira kwa mitundu ndi majini m'mibadwo yamtsogolo. Chinsinsi chomvetsetsa mitanda ya monohybrid ndikuzindikira zizindikiro za ma alleles akuluakulu ndi obwerezabwereza ndikutha kupanga ndikusanthula ma Punnett squares. Kuchita zinthu nthawi zonse ndi zitsanzo zosiyanasiyana kudzalimbitsa chidziwitso chathu cha majini oyambira ndikuwonjezera kumvetsetsa kwathu momwe makhalidwe amakhalira.
