Video: Yuav ua li cas tus tsim cov nyhuv ua rau cov noob caj noob ces?
2024 Tus sau: Miles Stephen | [email protected]. Kawg hloov kho: 2023-12-15 23:36
Genetic drift ua tau ua rau loj losses caj ces variation rau cov neeg me. A tus tsim teebmeem tshwm sim thaum lub colony tshiab yog pib los ntawm ob peb tug tswv cuab ntawm thawj cov pejxeem. Cov pejxeem me me no txhais tau hais tias cov colony yuav muaj: txo caj ces variation ntawm thawj cov pejxeem.
Tsis tas li ntawd paub yog, yuav ua li cas genetic drift coj mus rau evolution?
Genetic drift ua rau evolution los ntawm random caij nyoog vim sampling yuam kev, whereas natural xaiv ua evolution ntawm lub hauv paus ntawm kev tawm dag zog. Ntawd yog, tus neeg uas muaj lub cev muaj zog ntau dua yuav dhau mus rau nws caj ces khoom (alleles) rau tiam tom ntej.
Tsis tas li ntawd, dab tsi yog qhov cuam tshuam ntawm cov pej xeem loj ntawm random genetic drift? Genetic drift yog a random txheej txheem uas tuaj yeem ua rau muaj kev hloov pauv loj hauv cov pejxeem dhau lub sijhawm luv luv. Random drift yog tshwm sim los ntawm rov tshwm sim me me cov pejxeem loj , hnyav txo nyob rau hauv pejxeem loj hu ua "bottlenecks" thiab founder txheej xwm qhov twg ib tug tshiab pej xeem pib los ntawm cov neeg tsawg tsawg.
Kuj kom paub, dab tsi yog qhov tshwm sim ntawm tus tsim cov nyhuv?
Cov tus tsim teebmeem tuaj yeem muaj qhov tob cuam tshuam ntawm cov neeg me vim yog kev hloov ntawm caj ces. Cov cuam tshuam tuaj yeem nyob twj ywm thaum cov pej xeem tseem nyob ib leeg kom muaj kev hloov pauv caj ces tsawg. Inherited kab mob xws li retinitis pigmentosa thiab Ellis-van Creveld syndrome yog cov piv txwv ntawm cov qhov tshwm sim ntawm tus tsim nyhuv.
Yuav ua li cas tus tsim cov nyhuv ua rau kev hloov pauv hauv cov noob caj noob ces?
Qhov tshiab gene laug yog li ntawd yuav pib tawm nrog allele frequencies txawv los ntawm cov niam txiv gene laug . Yog hais tias ib tug pej xeem tsis evolving, allele frequencies nyob rau hauv nws gene laug tsis txhob hloov , uas txhais tau hais tias cov pejxeem nyob rau hauv caj ces kev sib npaug.
Pom zoo:
Dab tsi yog txhais los ntawm cov noob tseem ceeb thiab cov noob caj noob ces?
(Nyob rau hauv cov ntsiab lus ntawm caj ces, ib qho tseem ceeb tshaj plaws yog ib qho uas yog phenotypically qhia hauv heterozygotes). Ib qho tseem ceeb tshaj plaws yog tawm tsam qhov tsis zoo uas tshwm sim tsuas yog thaum muaj ob daim ntawv theej ntawm cov noob. (Nyob rau hauv cov ntsiab lus genetic, ib tug recessive zoo yog ib tug uas yog phenotypically qhia tsuas yog nyob rau hauv homozygotes)
Yuav ua li cas hloov cov noob caj noob ces muaj txiaj ntsig?
Cov kab mob kis tau kev hloov pauv thoob plaws hauv lawv lub neej. Cov kev hloov pauv no yog kev hloov pauv rau lawv txoj cai caj ces, lossis DNA. Txawm li cas los xij, qee zaus, kev hloov pauv tshwm sim uas muaj txiaj ntsig zoo rau lub cev. Cov kev hloov pauv tau zoo no suav nrog tej yam xws li lactose kam rau ua, nplua nuj xim tsis pom kev thiab, qee qhov, tiv thaiv kab mob HIV
Yuav siv cov noob caj noob ces li cas?
Cov txheej txheem caj ces yog cov txheej txheem uas siv los ntawm cov hlwb uas muaj sia nyob los txhais cov ntaub ntawv hauv cov khoom siv caj ces (DNA lossis mRNA cov kab ke ntawm nucleotide triplets, lossis codons) rau hauv cov protein. Txoj cai txhais li cas codons qhia meej tias cov amino acid yuav muab ntxiv tom ntej thaum lub sij hawm tsim cov protein
Dab tsi yog qhov txawv ntawm kev xaiv khoom tsim thiab kev tsim noob caj noob ces?
Artificial xaiv xaiv rau cov yam ntxwv uas twb muaj nyob rau hauv ib hom, whereas genetic engineering tsim cov yam ntxwv tshiab. Hauv kev xaiv dag, cov kws tshawb fawb yug tsuas yog cov tib neeg uas xav tau qhov zoo. Los ntawm kev xaiv kev yug me nyuam, cov kws tshawb fawb muaj peev xwm hloov cov cwj pwm hauv cov neeg. Evolution tau tshwm sim
Yuav ua li cas cov khoom siv caj ces hauv txhua lub xov tooj tshiab tsim los ntawm kev faib tawm ntawm tes sib piv nrog cov khoom siv caj ces hauv lub xov tooj qub?
Mitosis tshwm sim nyob rau hauv ob lub nuclei uas zoo tib yam rau thawj nucleus. Yog li, ob lub hlwb tshiab tsim tom qab kev faib tawm ntawm tes muaj tib yam khoom siv caj ces. Thaum lub sij hawm mitosis, chromosomes condense los ntawm chromatin. Thaum saib nrog lub microscope, chromosomes pom nyob rau hauv lub nucleus