Qhov sib txawv tseem ceeb ntawm kev saib xyuas thiab kev rov ua dua tshiab yog qhov kev rov ua dua tshiab ua rau ob lub helices uas ib lub helix muaj tag nrho cov niam txiv DNA qub thiab lwm qhov helix muaj tag nrho DNA tshiab thaum semiconservative replication tsim ob lub helices nyob rau hauv uas txhua strand ntawm ob lub helices tsim yuav muaj ib tug qub thiab ib tug tshiab strand.
DNA muaj nyob ua ob lub helix uas muaj ob txoj hlua sib txuas. DNA synthesis los yog DNA replication yog txheej txheem ntawm tsim replicas ntawm DNA los ntawm thawj DNA molecules. Yog li ntawd, nws yog ib qho tseem ceeb heev txheej txheem, raws li nws pab txhawb kev hla ntawm cov khoom siv caj ces los ntawm niam txiv mus rau cov xeeb ntxwv. Nyob rau hauv lwm yam lus, DNA replication yog lub hauv paus ntawm heredity los yog cov noob caj noob ces. Muaj peb txoj kev postulated DNA replication; xws li, semiconservative replication, conservative replication thiab dispersive replication. Ntawm peb qhov no, kev khaws cia thiab kev sib cais tsis pom muaj qhov tseem ceeb ntawm kev lom neeg.
Kev Tiv Thaiv Kev Txhaum Cai yog dab tsi?
Kev saib xyuas kev rov ua dua yog ib qho ntawm peb txoj hauv kev ntawm DNA replication. Thaum cov txheej txheem no, nws tsim ob DNA helices los ntawm ib tug thawj DNA helix. Tawm ntawm ob lub helices tsim, ib lub helix muaj tag nrho DNA qub thaum lub helix muaj DNA tshiab nkaus.
Daim duab 01: Kev Tiv Thaiv Kev Tiv Thaiv
Ntxiv mus, hom kev rov ua dua no tsis pom muaj qhov tseem ceeb hauv kev noj qab haus huv. Hauv cov qauv ntawm kev rov ua dua no, cov kws tshawb fawb ntseeg tias DNA tsis sib cais qhib txhua. Yog li ntawd, lawv tau sib cav tias qee yam ua rau niam txiv cov kab mob tsis tu ncua, tag nrho tshiab thiab cais cov ntawv DNA hauv cov qauv no.
Semiconservative Replication yog dab tsi?
Semiconservative replication yog hom biochemical tseem ceeb ntawm DNA replication uas tau npaj los ntawm Watson thiab Crick hauv xyoo 1953. Nyob rau hauv txoj kev no, tawm ntawm ob lub helices tsim, txhua lub helix muaj ib txoj hlua tshiab thiab ib txoj hlua qub. Raws li Watson thiab Crick, thaum lub sij hawm replication semiconservative, ib tug qub DNA strand ua tus qauv los tsim cov strand tshiab.
Daim duab 02: Semiconservative Replication
Li no, txhua qhov tshiab ob lub helix tsim muaj ib qho qub DNA strand txhua zaus. Txawm li cas los xij, hom DNA replication no yog qhov tsim nyog tshaj li ob hom, vim DNA polymerase enzyme xav tau cov qauv strand los tsim ib txoj hlua tshiab thiab muaj peev xwm sib txuas cov hlua tshiab nrog cov qauv strand thaum rov ua dua.
Dab tsi zoo sib xws ntawm Conservative thiab Semiconservative Replication?
- Kev saib xyuas thiab Semiconservative Replication yog ob hom DNA replication.
- Nyob rau hauv txhua txoj kev, ob ob lub helices tsim los ntawm qub DNA molecule.
Dab tsi yog qhov txawv ntawm Kev Saib Xyuas Kev Ncaj Ncees thiab Semiconservative Replication?
Kev saib xyuas thiab kev rov ua dua tshiab yog ob tus qauv tawm ntawm peb tus qauv ntawm DNA rov ua dua. Conservative replication yuav tsim ob helices, thiab ntawm lawv, ib tug muaj tag nrho cov qub DNA thaum lwm yam muaj tag nrho cov DNA tshiab. Semiconservative replication yog qhov kev xav ntawm DNA replication uas ua rau ob lub helices uas muaj ib qho qub strand thiab ib txoj hlua tshiab. Thaum tsim cov strand tshiab, yuav tsum muaj cov qauv strand rau DNA polymerase ntxiv nucleotides hauv cov qauv semiconservative. Cov hauv qab no inforgraphic nthuav qhia cov ncauj lus kom ntxaws ib sab ntawm kev sib piv ntawm qhov sib txawv ntawm kev saib xyuas thiab kev hloov pauv semiconservative.
Summary – Conservative vs Semiconservative Replication
Kev saib xyuas thiab kev rov ua dua tshiab yog ob tus qauv uas tau thov rau DNA rov ua dua. Hauv kev khaws cia rov ua dua tshiab, cov kws tshawb fawb ntseeg tias DNA tsis ua kom tsis muaj zog thiab thaum ua kom lawv nyob ruaj khov, DNA tshiab helices tsim los ntawm DNA qub. Yog li ntawd, kev saib xyuas kev rov ua dua tau ua tiav tag nrho ib qho qub DNA helix thiab ib qho tshiab DNA helix nkaus. Nyob rau hauv semiconservative replication, txhua helix tshiab tsim muaj ib tug tshiab strand thiab ib tug qub strand. Conservative replication qauv tsis pom tias nws yog ib qho tseem ceeb ntawm cov khoom siv hluav taws xob ntau dua li semiconservative replication. Li no, qhov no yog qhov sib txawv ntawm kev saib xyuas thiab kev rov ua dua tshiab.
