Yog ob niam txiv yog heterozygous (Ww), muaj a 75% muaj feem uas ib tug ntawm lawv cov xeeb ntxwv yuav muaj ib tug poj ntsuam lub ncov (saib daim duab). Punnett square Punnett square Lub Punnett square yog cov ntsiab lus ntawm kev sib txuas ntawm niam txiv alleles nrog leej txiv alleles. Cov ntxhuav no tuaj yeem siv los tshuaj xyuas qhov tshwm sim ntawm qhov tshwm sim ntawm cov xeeb leej xeeb ntxwv ntawm ib qho kev zoo (allele), lossis thaum hla ntau yam ntawm cov niam txiv. https://en.wikipedia.org › wiki › Punnett_square
Punnett square - Wikipedia
tuaj yeem siv los txiav txim siab txhua qhov kev sib txuas ntawm cov genotypic hauv cov niam txiv. Ib tug pedigree uas piav txog ib qho tseem ceeb ntawm qhov qub txeeg qub teg muaj ob peb yam tseem ceeb.
ob niam txiv puas tuaj yeem ua neeg heterozygous?
Piv txwv li hauv cystic fibrosis yog tias ob leeg niam txiv yog heterozygous, txhua tus menyuam muaj 25% txoj hmooyug los nrog cystic fibrosis. Qee cov kab mob caj ces yog tshwm sim los ntawm cov noob tseem ceeb. Tib txoj kev uas ib tug neeg yuav muaj tus kab mob no yog tias ib tug ntawm lawv niam lawv txiv muaj nws (thiab ib tug ntawm lawv pog thiab yawg thiab lwm yam).
txhais tau li cas thaum ob niam txiv yog heterozygous?
Lo lus "heterozygous" tsuas yog txhais tau tias koj niam thiab koj txiv yug, thaum lawv muab lawv cov ntawv luam ntawm cov noob rau koj, lawv tau ua li ntawd. tias DNA sib lawv liag txawv me ntsis.
Qhov tshwm sim yog dab tsi uas obniam txiv heterozygous?
Lub caij nyoog ntawm leej niam leej txiv ua tus heterozygote yog 1/4, raws li suav saud. Tom qab ntawd, qhov tshwm sim uas ob niam txiv yog heterozygotes, thiab qhov tshwm sim uas ob lub heterozygotes yuav muaj tus menyuam heterozygous, yog 1/4 x 1/4 x 1/2=1/32.
Puas yog heterozygous ob qho tseem ceeb?
Nyob rau hauv ib tug heterozygous genotype, ob qho alleles sib cuam tshuam nrog ib leeg. … Cov allele uas tau hais ntau zog yog hu ua "dominant," thaum lwm qhov hu ua "recessive." Qhov no recessive allele yog npog los ntawm tus tseem ceeb.
