Mosebetsi wa chromosomes le sebopeho bona. Seo etsang chromosomes ka seleng?

Sehlooho sena se tla bua le sebopeho sa eukaryotic lisele tse, chromosomes, sebopeho le mosebetsi ba ithutile indasteri ea baeloji, e bitsoang cytology.

History of sibolloa

E le ka sehloohong motsoako oa khubung seleng, chromosome ile ha fumanoa a lekholo la bo19 la lilemo ke bafuputsi ba 'maloa. A setsebi sa baeloji Russia I. Chistyakov ithutile tsona nakong mitosis (karohano seleng e), Jeremane anatomist Heinrich Wilhelm Gottfried av Waldeyer-Hartz sibolla bona nakong ya ba lokisetsa ho ea ka litokisetso histological 'me a bitsa chromosomes, e staining manamane karabo kgaoletsang mehaho tsena ka sebelisana le manyolo dae magenta.

Fleming o ile a akaretsa bopaki saense ka seo mosebetsi o etsoa ke chromosomes le liseleng tse khabisitsoeng motheo.

sebopeho External tsa chromosomes

Tsena sebopeho tse nyenyane sebakeng nuclei ba - ea bohlokoa ka ho fetisisa lisele tsa organelles le ho sebeletsa e le sebaka sa polokelo le phetiso ya tlhahisoleseding lefa la ntho e phelang. Chromosomes na le motsoako o khethehileng - chromatin. Ke conglomeration ea linaleli e metle - fibrils le granules. From k'hemik'hale ponong, sena motsoako oa guttate limolek'hule DNA (ka bang 40%) le liprotheine itseng histone.

Mehahong tse akarelletsang peptides 8 le limolek'hule tsa DNA khoele e ohliloeng sothile ka globules protheine, ka makhetlo a bitsa nucleosomes. Plot acid e deoxyribonucleic karolo 1,75 liphetohelo pota theko kabelo le na le sebōpeho sa e ellipsoid ka nanometers 10 ka bolelele 'me 5-6 ka bophara. Ho ba teng ha dibopeho tsena (chromosomes) ka liboto le o sebeletsa e le taxonomic tšobotsi lisele tse eukaryotic. Ho ka mokgwa wa nucleosomes chromosomes sebetsa e le sa ho boloka le phetiso ea litšobotsi tse liphatsa tsa lefutso.

The ho itšetleha ya sebopeho sa chromosomes ya mohato seleng ea potoloho

Ha sele e interphase, e tšoauoa ka hōle le matla haholo le metabolism, empa ho hloka karohano, ho chromosomes ka khubung ea na le mofuta o mong oa linaleli tšesaane despiralizovannyh - chromonemata. Hangata di lohellana, 'me pono arola ba kenya dibopeho arohaneng etsahala. Ka nako e sa qala ho ea karohano seleng, e leng ke ka lisele tse somatic o bitsoa mitosis, 'me ba kopanela liphate - meiosis, chromosomes qala ho helical le thicken, ba bonahalang ho feta ka ya microscope ho.

Maemo tsa mokhatlo o hlophisitsoeng oa chromosomes

Diyuniti tsa lefutso - chromosome, hlahloba ka ho qaqileng ea saense liphatsa tsa lefutso. Bo-rasaense ba fumane hore nucleosomal thread se se akaretsang DNA-histone liprotheine theha spiral tle pele. The paka le letšo-letšo la sebopeho chromatin le hlaha ka lebaka la hore ho thehoe odara e phahameng - solenoid. O hlophisa le ho o tiisa ka esita le rarahaneng ka ho feta e ikharileng-kela. All ho tse ka holimo maemo mekhatlo chromosome li lokisetsa lisele ho arola.

Ho ka mitotic potoloho mehaho ya ka yuniti ya lefutso, e bopilweng ka liphatsa tsa lefutso tse nang le DNA li shortened le thatafetseng bapisoa le filiform chromonemata interphase nako ka bang 19 tse sekete. Times. Sena diseke ee mofuta o chromosome khenele mesebetsi eo ke ho fetisetsa litšobotsi tse liphatsa tsa lefutso ea phelang, ke loketse ho arola somatic kapa kokoana-hloko liseleng.

The phetoho ea chromosomes ho

chromosomes mosebetsi ka hlalosoa ka ho ithuta makgetheng bona morphological hore ba molemo ka ho fetisisa amahanngoa ka potoloho ea mitotic. E paka hore ka ho ba sethaleng maiketsetso tsa interphase boima ba DNA ka seleng e imenne habeli hobane e mong le e seleng ea morali oa thehoa ka ho arola, ba lokela ho ba ka tsela e lekanang ea boitsebiso bo liphatseng tsa lefutso e le motsoali oa pele. Sena se finyelloa ka thulaganyou e boikatiso - the intša palopedi DNA nkiloeng ke potlakisang tsebetso ea lik'hemik'hale DNA polymerase.

Ka litokisetso cytological lokisetsa ka nako ya metaphase tsa mitosis ka semela kapa phoofolo lisele tse tlas'a ya microscope ho hlaka hore e mong le chromosome e entsoe ka likarolo tse peli, e bitsoang chromatids. Ka mekhahlelo e ileng ea latela tsa mitosis - anaphase me haholo-holo telophase - karohano ka ho feletseng etsahala, oo ka oona e mong le e chromatid fetoha chromosome arohaneng. Ho kenyelletsa ditokiseletso tswelela pele katiloe DNA molek'hule, hammoho le lipids, liprotheine acid e le RNA. Matsoai dintho e na le magnesium le khalsiamo ions.

Tshehetso mehaho likarolo chromosome

Ho chromosome mosebetsi ka seleng ba ileng ba tsoa ka botlalo, diyuniti tsena tsa lefutso tse e khethehileng sesebediswa - e constriction mathomo (centromere), e leng mohla spiralizuetsya. Hore e arola le chromosome likarolo tse peli, e bitsoang mahetleng ka. Ho itšetlehile ka lefelo la centromere e, chromosome liphatsa tsa lefutso classified ka lekanang angle (metatsentrichnye) neravnoplechie (submetacentic) le akrotsentrichnye. Ka thuto e khethehileng constrictions mathomo ba thehoa - kinetochores, tse tiske-joaloka protheine globules teng ka mahlakoreng a mabeli ba centromere ena. Sami kinetochores bopilwe likarolo tse peli: ho ikopanya Link le microfilaments (threaded leakage radiation) khomaretse ho bona.

Ka ho fokotsa linaleli (microfilaments) e tieo o ile a laela kabo chromatids se se akaretsang sa chromosome pakeng tsa lisele tse morali. Ba bang ba chromosomes na le 'ngoe kapa ho feta constrictions mahareng, tse ha a amehe mitosis, kaha li ka' na ha kena khoele leakage radiation, empa libakeng tsena (constrictions mahareng) fana taolo ya tswakana tsa nucleoli - organelles hore ba na le boikarabelo bakeng sa sebopeho sa ribosomes.

ke karyotype seo

Tsebahalang geneticists Morgan, N. Koltsov, Sutton ka mathoasong a lekholo la bo20 la lilemo, ka hloko o ile a ithuta chromosome sebopeho le mosebetsi liseleng somatic le kokoana-hloko - diretswe go dira gametes. Ba ile ba fumana hore e mong le seleng ea ba mefuta e sa tsohle tse tloaelehileng tsa e itseng eo di ea chromosomes ho ba le sebopeho itseng le boholo. Ho ile ha boleloa hore le bothe tsa chromosomes ka khubung ea lisele somatic bitsoa karyotype.

Ka lingoliloeng karyotype ratoang hangata ile ba bapisa le sete ya chromosome. Ha e le hantle, ho ke ke ha bopa dikgopolo tsa tšoanang. Mohlala, karyotype batho ke chromosomes 46 ka nuclei ea lisele somatic le khethiloe ka kakaretso moralo 2n. Empa lisele tse joalo, tse kang hepatocytes (lisele tse sebete) na nuclei tse seng kae, chromosomal bona motlatsi denoted ka 2n * 2 = 4n kapa 2n * 4 = 8n. Ke hore, palo ea chromosomes liseleng tsena tla ba ho feta 46, le hoja karyotype tsa hepatocytes ke 2n, joale ho na le 46 chromosomes.

palo ea chromosomes liseleng kokoana-hloko kamehla makhetlo a mabeli tlase ho ka somatic (liseleng tsa 'mele), sete ena o bitsoa haploid le o bitsoa n g. All liseleng tse ling 'meleng ba le sete ya 2n, e bitsoang diploid phase.

Morgan o chromosome khopolo ea ho ja lefa la hae

American sa liphatsa tsa lefutso Morgan a sibolla molao oa amahanngoa le lefa la liphatsa tsa lefutso, ho etsa liteko ka hybridization tsa lintsintsi litholoana, lintsintsi tsa litholoana. Ka ho etsa lipatlisiso tsa hae, ho sebetsa ha chromosomes thobalano ea lisele li ne li ithutileng tsona. Morgan bontšitse hore liphatsa tsa lefutso teng naheng ea boahelani ea loci ba chromosome e tšoanang, bogolosegolo futsitseng hammoho, i.e. clutch ena. Ha liphatsa tsa lefutso ho ba sebakeng se chromosome hole ho e mong le tse ling tse, pakeng tsa ausi oa chromosomes khoneha tšela-fetang - arolelana libaka.

Ka lebaka la ho etsa lipatlisiso ba Morgan, li ile tsa bōptjoa limmapa liphatsa tsa lefutso, tseo ka tsona ithuta ho sebetsa ha chromosomes le ho sebelisa ha bona a pharaletseng ka tlhabollo liphatsa tsa lefutso ho rarolla litaba tsa pathologies khoneha ya chromosomes kapa liphatsa tsa lefutso ho baka mafu a lefa ka batho. Bohlokoa ba ho etsa liqeto tsa bo-rasaense ba, ho ke ke ho le thata ho feteletsa.

A sehloohong sena a, re nahana ka sebopeho le mosebetsi wa chromosomes, eo ba phetha ka seleng.