2024 Tus sau: Elizabeth Oswald | [email protected]. Kawg hloov kho: 2024-01-13 00:07
Thaum meiosis, homologous chromosomes (1 ntawm txhua tus niam txiv) ua khub raws lawv qhov ntev. Chromosomes hla ntawm cov ntsiab lus hu ua chiasma. Ntawm txhua chiasma, cov chromosomes tawg thiab rov ua dua, ua lag luam qee yam ntawm lawv cov noob. Qhov kev rov ua dua no ua rau muaj kev hloov pauv caj ces.
Yuav ua li cas rov ua kom muaj kev hloov pauv?
Homologous Recombination
paired chromosomes los ntawm txiv neej thiab poj niam niam txiv sib dhos kom zoo sib xws DNA sib lawv liag los ntawm khub chromosomes hla ib leeg. Kev hla dhau qhov tshwm sim hauv kev sib hloov ntawm cov khoom siv caj ces thiab yog ib qho tseem ceeb ntawm kev hloov caj ces pom ntawm cov xeeb ntxwv.
Qhov cuam tshuam ntawm kev sib koom ua ke yog dab tsi?
Recombination kuj tau hloov kho los ntawm ntau yam ntawm ib puag ncig stimuli, suav nrog kub [5] thiab mob [6]. Recombination muaj cov txiaj ntsig zoo rau kev noj qab haus huv: piv txwv li, hauv tib neeg, kev hloov pauv ntawm kev sib txuas ua ke tuaj yeem ua rau chromosomal txawv txav, txo qis fertility thiab kab mob [7].
Dab tsi yog recombination Vim li cas thiaj tseem ceeb?
Tshaj tawm nws lub luag haujlwm hauv meiosis, kev rov ua dua yog qhov tseem ceeb rau cov hlwb somatic hauv eukaryotes vim nws tuaj yeem siv los pab kho DNA puas, txawm tias thaum tawg cuam tshuam nrog ob txoj hlua ntawm ob. helix. … Tom qab ntawd, ib zaug ua ke, DNA tshiab no tuaj yeem muab tso rau hauv cov DNA uas tawg, yog li kho nws.
Dab tsi yog qhov txawv ntawm kev sib koom ua kethiab mutation?
Mutations muab thawj qhov chaw ntawm ntau haiv neeg los ntawm kev hloov cov haujlwm tshwj xeeb thiab kev sib txuas ua ke ntawm cov kev hloov pauv los ntawm pauv cov caj ces txuas ntxiv txhawm rau nce cov caj ces hloov pauv.
Pom zoo:
Vim li cas recombination zaus tsis tshaj 50?
Qhov kev sib xyaw ua ke ntawm ob lub noob tsis tuaj yeem siab dua 50% vim tias kev sib txawv ntawm cov noob tsim 50% rov ua dua tshiab (cov noob tsis sib txuas ua rau 1: 1 niam txiv rau cov niam txiv tsis yog niam txiv. niam txiv/tag nrho → 1/(1+1)=50%).
Yuav kom dna molecules mus rau recombination?
Yuav kom DNA molecules mus rau recombination, … ib ntawm ob DNA strands yuav tsum degraded . DNA molecules tau txais kev sib txuas ua ke li cas? Recombinant molecules nkag mus rau hauv cov hlwb nyob rau hauv cov txheej txheem hu ua transformation.
Yuav ua li cas txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau txhawm rau pom kev pom?
Txawm li cas los xij, corneal collagen cross-linking - cov txheej txheem qib siab tau pom zoo los ntawm US Food and Drug Administration (FDA) hauv xyoo 2016 - tuaj yeem txhim kho qhov pom kev hauv cov neeg mob txhua hnub nyoog. Corneal collagen cross-linking (CXL) tsis yog kho rau keratoconus, tab sis nws tuaj yeem pab tiv thaiv tus mob kom tsis txhob mob hnyav.
Formula rau recombination zaus?
Recombination zaus= recombinants/tag nrho progeny x 100. Kev sim recombination zaus ntawm ob lub noob tsis muaj ntau dua 50%. Recombinant zaus yog dab tsi? A tus lej uas piav qhia txog kev faib ua feem ntawm cov xeeb ntxwv uas tsim tawm hauv cov noob caj noob ces ntawm ob kab mob.
Yuav ua li cas txhawm rau txhawm rau txhawm rau sib npaug?
Nyob rau hauv txhua pab pawg, xauv tuaj yeem raug yuam kom sib npaug yog tias xav tau. Cov locks no tseem yuav ua haujlwm los ntawm tus yawm tswv qhov tseem ceeb. Cov txheej txheem no siv qhov twg 2 lossis ntau dua qhov tseem ceeb ntawm tus tswv lag luam yuav tsum tau ua, nrog rau txhua tus tswv lag luam tseem ceeb muaj peev xwm ua tau los ntawm tus yuam sij loj loj.
