Txhua lub xovtooj ntawm lub cev ntawm cov neeg muaj sia nyob ntawm eukaryotes muaj cov saw hlau polymer ntawm DNA hauv lub nucleus, uas yog lub ntsiab "txoj haujlwm" ntawm lub neej. Tib neeg DNA yog cov khoom siv caj ces uas txhua tus poj koob yawm txwv nco, cov kab mob uas tus neeg tau txais kev pom zoo, thiab tag nrho cov txuj ci ntawm tus neeg raug kaw. Ib txheej ntawm 23 khub noob caj noob ces yog lub hauv paus ntawm tib neeg caj ces apparatus
Kom nkag siab tias DNA tseem ceeb npaum li cas, koj yuav tsum paub nws cov qauv thiab kev ua haujlwm. DNA tsis yog ib txoj cai xwb, nws yog tus qauv tseem ceeb uas lub cell tsim cov proteins los ntawm cov amino acids thiab npaj cov hlwb tshiab uas yuav hloov nws lub sijhawm. Qhov no yog yuav ua li cas lub neej ntawm lub cev yog guaranteed.
Human genetics. Cov ntsiab lus tseem ceeb
Chromosomes, los yog chromatid threads, yog qhov chaw ntawm lub nucleus thiab muab lub neej rau ib leeg thiab tag nrho cov kab mob. Chromosomes yog tsim los ntawm cov noob. Ib lub noob yog ib chav tsev uas nqa lub cim xeeb ntawm cov poj koob yawm txwv. Cov txheej txheem ntawm noob neej hu ua genome.
Cov cuab yeej caj ces suav nrog lub hauv paus, thiabDNA nws muaj. DNA tsis tuaj yeem nyob tsis muaj kev pab - tub txib RNA thiab thauj - tRNA. Cia peb tham txog RNA tom qab. Tam sim no cia peb piav qhia seb DNA yog dab tsi.
DNA polymer muaj nyob hauv chromosomes. Ob txoj hlua khi sib txuas tau txuas nrog raws li lub hauv paus ntsiab lus ntawm kev sib txuas.
DNA - deoxyribonucleic acid - yog ib qho polymer molecule uas muaj lub tsev blocks ntawm nucleotides. Lub DNA code yog ib ntu ntawm 4 nucleotides muab rau ib tus neeg tshwj xeeb: adenine, thymine, guanine thiab cytosine.
Chromosome yog dab tsi? Ib chromosome yog ib chav loj ntawm lub koom haum ntawm cov khoom siv caj ces hauv ib lub xovtooj ntawm tes. Nws muaj ntau txhiab cov noob "packed" rau hauv qee yam qauv. Txhua chromosome muaj ib centromere thiab ob telomeres.
Cov kab ke nucleotide hauv chromosome encodes cov ntaub ntawv hais txog cov qauv ntawm lub cev proteins. Thiab thaum lub teeb liab los txog tias lub cev xav tau cov protein tshiab, DNA sib cais, luam tawm, thiab rov ua kom zoo dua qub.
Tus yam ntxwv ntawm cov cuab yeej genetic apparatus
Peb cov teeb tsa chromosome muaj ob peb yam tseem ceeb. Cov kws tshawb fawb tau tswj xyuas dab tsi, cov khoom dab tsi muaj cov noob? 3 yam tseem ceeb ntawm tib neeg cov noob tau paub.
- Kev khaws cia rau tus kheej.
- Kev ua si tus kheej.
- Mutability.
Lo lus "gene" tau qhia txog kev tshawb fawb los ntawm W. Johansen hauv xyoo 1909. Lub luag haujlwm dab tsi ua qhov kev hloov pauv no ua haujlwm?
- Gene xa xov rau lwm tiam neeg.
- Muab cov ntaub ntawv rov ua dua.
Cov cuab yeej caj ces ntawm tib neeg lub xov tooj yog tsim los ntawm xwm hauv txoj kev tsim nyog thiab nyuaj heev. Cov chav me me ntawm cov cuab yeej cuab tam - noob - ua kom loj dua thiab compactly nyob rau hauv chromatin filaments. Ob txoj xov zoo li no tau sib cuam tshuam ua tsaug rau cov protein tshwj xeeb thiab lub centromere.
Yam kev ua neej nyob hauv DNA li cas?
Lub hnub nyoog laus yog qhov pom tseeb hauv lub tshuab tsom, thiab kev puas tsuaj tuaj yeem txiav txim siab los ntawm lub xeev ntawm chromosome telomeres.
Chromosomal strands, muaj ib ntu ntawm cov noob, maj mam luv tom qab txhua qhov kev faib tawm. Qhov me me ntawm cov telomeres dhau los ua tom qab rov faib cov xov tooj ntawm tes, cov khoom siv tseem ceeb tshaj yog siv. Thiab, yog li ntawd, kev laus thiab kev tuag ntawm lub cev yog inevitably mus.
Diploid thiab haploid pawg ntawm chromosomes
Hauv cov hlwb ntawm qee cov kab mob muaj cov chromosomes haploid, hauv lwm tus nws yog diploid. Qhov txawv yog dab tsi? Hauv cov tsiaj uas yug me nyuam sib deev, muaj ob pawg chromosomes nyob rau hauv lub nucleus - diploid. Ib tug neeg yeej ib txwm muaj diploid teeb.
Tag nrho lwm yam, tsis tshua tsim muaj sia nyob muaj ib txheej hauv lawv lub hlwb - uas yog, lawv haploid.
DNA ua haujlwm
Tag nrho cov txheej txheem ntawm lub cell nucleus ua haujlwm hauv tib "hom", yam tsis tso cai ua tsis tiav, kom lub cell tuaj yeem ua haujlwm tau zoo.
Thaum lub cell xav tau los tsim cov protein tshiab, cov qauvuas yog encrypted nyob rau hauv DNA, "lub Hoobkas" ntawm cov proteins yuav tsum luam cov ntaub ntawv no thiab nyeem nws. Qhov no yuav tsum tau tRNA thiab mRNA.
Lwm lub luag haujlwm tseem ceeb ntawm cov cuab yeej caj ces yog khaws cia nws cov cai, hloov tag nrho cov ntaub ntawv muaj txog kev loj hlob ntawm cov tiam dhau los rau cov menyuam yug tshiab.
Cov ntaub ntawv dav dav txog tib neeg DNA
Dab tsi yog ib qho deoxyribonucleic acid saw? DNA strand yog ob npaug. Nws yog ntom ntom ntim rau hauv chromosomes kom tag nrho cov ntaub ntawv no tuaj yeem haum rau hauv lub nucleus, uas tsis pub tshaj 510 -4inch. Whereas tag nrho ntev ntawm unfolded tib neeg DNA saw yog yuav luag 2 m.
Ib tug neeg muaj "tus qauv" txheej ntawm 23 khub ntawm chromosomes hauv ib lub xovtooj ntawm tes - ib khub niam txiv, lwm tus los ntawm leej txiv; thiab 2 kev sib deev chromosomes - XX lossis XY.
Thawj zaug, J. Watson thiab F. Crick tau tshawb pom peb-seem qauv ntawm helical DNA. Los ntawm txoj kev, J. Watson yog thawj tus neeg uas nws DNA code tau txiav txim siab thiab luam tawm hauv phau ntawv journal.
Ib lub saw hlau polynucleotide yog tsim los ntawm kev sib xyaw ua ke ntawm nucleic acids - purines thiab pyrimidines. Xws li cov kua qaub ib txwm muaj 3 cov tshuaj - pentose, ib qho nitrogenous puag thiab ib feem ntawm phosphoric acid.
Qhov tshwm sim ntawm kev hloov pauv ntawm chromosome
Cov cuab yeej caj ces tsis yog cov khoom siv "repository" ntawm cov ntaub ntawv tseem ceeb, tab sis kuj yog cov khoom muaj sia nyob. Chromosomes tsiv mus nyob ib ncig ntawm lub nucleus, faib thaum xav tau.
Chromosome qauv tseem zoo ib yam tom qab txhua qhov kev faib. Yogmuaj tsawg kawg yog ib qho yuam kev, lub cev yuav tau pib malfunction. Dab tsi txhais DNA? Nws zais cov khoom lom neeg ntawm karyotype - cov yam ntxwv ntawm cov duab thiab xim ntawm cov kev kawm, qhov tshwj xeeb ntawm nws lub koom haum sab hauv thiab sab nraud. Txhua lub cev ua haujlwm raws li cov txheej txheem, uas tau sau tseg hauv cov saw hlau polynucleotide ntawm txhua lub hlwb. Nws tuaj yeem raug sau tseg tias DNA kuj muaj "kev npaj ua haujlwm" ntawm somatic cell.
Yog vim li cas kev hloov pauv hauv chromosomes ntawm tus menyuam yug tshiab qee zaum ua rau muaj qhov tsis zoo, lossis phem dua, kev tsis taus.
Role of RNA
Ribonucleic acid, lossis RNA, kuj yog nucleotide uas tuaj yeem nkag mus rau lub nucleus, "nyeem" cov ntaub ntawv DNA thiab luam cov seem uas xav tau rau kev tsim cov protein. Neeg xa xov liaison RNA nyeem nyob rau hauv ib txoj kev cov ntaub ntawv hais txog cov qauv ntawm cov protein uas xav tau, thiab ntsiag to tawm lub nucleus.
Tom qab ntawd, raws li nws lub hauv paus, cov nucleotides muaj nyob hauv lub cev ntawm qhov npaj tau raug xaiv raws li lub hauv paus ntsiab lus ntawm kev sib xyaw ua ke - lawv tau "nqa" mus rau qhov chaw ntawm tRNA sib dhos - thiab tsim cov protein tshiab. RNA thiab DNA ua haujlwm ua ke. Tsis muaj leej twg yuav nyob tsis tau.
