2024 Tus sau: Elizabeth Oswald | [email protected]. Kawg hloov kho: 2024-01-13 00:07
DNA methyltransferases zoo li tau ntxim nyiam rau thaj chaw chromatin nrog cov kev hloov kho histone tshwj xeeb. Highly methylated (hypermethylated) DNA cheeb tsam nrog deacetylated histones yog nruj coiled thiab transcriptionally inactive.
DNA yog dab tsi transcriptionally inactive?
Heterochromatin yog kev hloov pauv tsis ua haujlwm ntawm DNA vim yog kev sib txuas ntawm DNA qauv hauv DNA-protein complexes. Gene Amplification: Cov noob tau nthuav tawm nyob rau theem siab, xws li rRNA, tRNA, thiab histone mRNA cov noob feem ntau muaj nyob rau hauv cov ntawv luam siab.
Yuav ua li cas hom chromatin yog transcriptionally inactive?
Ob hom chromatin, heterochromatin thiab euchromatin, yog qhov ua haujlwm thiab cov qauv sib txawv ntawm cov genome. Heterombatin yog densely ntim thiab nkag tau rau cov khoom siv hloov kom yog li nws tau muab cov khoom sib txuas (Richards thiab cov elgaw 2002).
Yuav ua li cas hauv qab no tsis muaj kev hloov pauv?
Nws yog hu ua euchromatin. Nws yog transcriptionally nquag chromatin whereas heterochromatinyog transcriptionally inactive thiab lig replicating los yog heteropycnotic.
DNA yog dab tsi?
Lub Sijhawm: transcriptionally nquag chromatin. Lus Txhais: Qhov kev txiav txim thiab koom ua ke ntawm DNA thiab cov protein uas tsim cov cheeb tsam ntawm cov chromosome uas tau ua haujlwm zoo.
Pom zoo:
Dab tsi yog qhov hloov pauv thiab hloov pauv hloov pauv?
Point mutations hloov ib leeg nucleotide. Frameshift kev hloov pauv yog ntxiv lossis tshem tawm ntawm nucleotides uas ua rau muaj kev hloov pauv hauv kev nyeem ntawv. frameshift thiab point mutation yog dab tsi? Ib qho kev hloov pauv cuam tshuam rau ib khub hauv paus.
Qhov kev hloov pauv no puas yuav ua rau muaj kev hloov pauv hloov pauv?
Yog li, yog tias muaj kev hloov pauv, piv txwv li, kev ntxig lossis tshem tawm ntawm nucleotide, tshwm sim, qhov no tuaj yeem ua rau kev hloov pauv ntawm kev nyeem ntawv. Nws hloov tag nrho cov amino acid ib ntus. Cov kev hloov pauv no yog hu ua frameshift mutation (tseem hu ua kev nyeem ntawv hloov pauv, nyeem ntawv hloov pauv, lossis framing yuam kev).
Qhov twg yog qhov kev hloov pauv hloov pauv hloov pauv?
Semiconservative replication piav qhia txog cov txheej txheem ntawm DNA replication nyob rau hauv tag nrho cov paub hlwb. DNA replication tshwm sim ntawm ntau lub hauv paus pib ntawm kev rov ua dua raws DNA qauv strand. Raws li DNA ob chav helix yog unwound by helicase, replication tshwm sim nyias ntawm txhua tus qauv strand nyob rau hauv antiparallel cov lus qhia.
Qhov kev hloov pauv twg yog xav tias yuav cuam tshuam los ntawm kev hloov pauv hloov pauv?
Dependent Variable Qhov sib txawv uas nyob ntawm lwm yam uas ntsuas. Cov kev hloov pauv no yuav tsum tau hloov pauv raws li qhov kev sim ua haujlwm ntawm tus kheej hloov pauv lossis hloov pauv. Nws yog cov nyhuv presumed. Qhov kev tshawb fawb hloov pauv twg yog qhov tshwm sim?
Los ntawm kev hloov pauv hloov pauv hloov pauv?
Kev hloov pauv hloov pauv hloov pauv (TMA) yog qhov isothermal (tsis hloov pauv nucleic acid kub), ib leeg-tube nucleic acid amplification system siv ob lub enzymes, RNA polymerase thiab thim rov qab kev sau ntawv. … Cov txheej txheem no tuaj yeem siv los tsom rau RNA thiab DNA.
