Kapangidwe ka Chromosome mu Nucleus ya Eukaryotic
Ma chromosome ndi zinthu zovuta zomwe zili mkati mwa nucleus ya maselo a eukaryotic. Amagwira ntchito yofunika kwambiri pakusunga, kubwerezabwereza, ndi kufotokoza chidziwitso cha majini. M'nkhaniyi, tifufuza mozama kapangidwe ka ma chromosome a eukaryotic, kumvetsetsa zigawo zake zoyambira, njira zoyendetsera zinthu, ndi kufunika kwawo pankhani ya zamoyo zamaselo ndi mamolekyu.
Chiyambi: Kodi Chromosome ndi chiyani?
Ma chromosome ndi mapangidwe ofanana ndi ndodo opangidwa ndi DNA ndi mapuloteni. Mu maselo a eukaryotic, ma chromosome amapezeka mu nyukiliyasi. Mwachitsanzo, selo la munthu lili ndi ma chromosome 46, omwe ali ndi ma chromosome 23 ofanana.
Kapangidwe Koyambira ka Ma Chromosomu
1. DNA: Chinthu chofunika kwambiri pa chromosome ndi DNA (deoxyribonucleic acid). DNA ndi molekyulu yayitali ya polima yomwe imasunga chidziwitso cha majini. Molekyulu iliyonse ya DNA mu chromosome imakulungidwa ndikukanikizidwa kukhala mawonekedwe opapatiza mothandizidwa ndi mapuloteni.
2. Ma Histone: Mapuloteni a Histone ndi mapuloteni omangira omwe amagwira ntchito yofunika kwambiri pakukonza DNA. DNA imazungulira zingwe za histone, ndikupanga mapangidwe otchedwa nucleosomes. Nucleosome imakhala ndi ma base pairs pafupifupi 147 a DNA omwe amazungulira pakati pa mapuloteni asanu ndi atatu a histone (histone octamer).
3. Chromatin: Kuphatikiza kwa mapuloteni a DNA ndi histone kumatchedwa chromatin. Chromatin imatha kuwoneka m'njira ziwiri:
– Euchromatin: Malo omasuka komanso ogwira ntchito ngati transcription, omwe amalola ma enzymes olembera ndi zinthu zina kuti zilowe mu DNA.
– Heterochromatin: Malo omwe ndi okhuthala komanso osagwira ntchito kwambiri polemba, ofanana ndi majini omwe selo silifunikira nthawi zina.
Phukusi la Chromosome: Kuchokera ku DNA kupita ku Chromosome
DNA yayitali ya eukaryotic iyenera kufupikitsidwa kuti igwirizane ndi nucleus ya selo laling'ono. Njirayi imaphatikizapo magawo angapo a dongosolo:
1. Nucleosomes: Gawo loyamba la kapangidwe kake lomwe latchulidwa kale. Nucleosomes zimathandiza kuchepetsa kutalika kwa DNA yomwe ikupezeka mwa kuikulunga mu tinthu tofanana ndi mikanda.
2. Ulusi wa 30 nm: Nucleosomes imapindidwanso kukhala ulusi wa chromatin womwe uli ndi mainchesi pafupifupi 30 nm. Izi zimapangitsa kuti DNA igwirizane kwambiri ndipo imatha kuzizira kwambiri pazigawo zina, monga nthawi yogawa maselo.
3. Malo Ozungulira: Ulusi uwu wa 30 nm umakulungidwa m'malupu omwe amamangiriridwa ku msana wa puloteni, ndikupanga kapangidwe kokhuthala. Malupu awa amatha kukonzedwanso m'malupu apamwamba.
4. Kukhuthala kwa Chromosome: Pa nthawi ya mitosis kapena meiosis ya kugawikana kwa maselo, ma chromosome amachulukirachulukira mpaka atawonedwa ndi maikulosikopu yowala. Iyi ndi mlingo wapamwamba kwambiri wa kukhuthala, kuonetsetsa kuti chidziwitso cha majini chikugawidwa bwino kwa maselo aakazi.
Udindo Wogwira Ntchito ndi Kufunika kwa Kapangidwe ka Chromosome
1. Kubwerezabwereza kwa DNA: Kapangidwe ka ma chromosome kamalola kubwerezabwereza kwa DNA molondola komanso moyenera maselo asanagawikane. Chromosome iliyonse imabwerezabwereza kotero kuti selo lililonse lachikazi limalandira ma chromosome athunthu.
2. Kulemba kwa DNA: Kukhalapo kwa euchromatin yomasuka kumalola kufotokozera majini ofunikira kuti maselo azigwira ntchito, pomwe gulu la heterochromatin limasunga majini osagwira ntchito pansi pa mikhalidwe ina.
3. Kugawa kwa majini panthawi yogawa: Kuchulukana kwa ma chromosome panthawi ya mitosis ndi meiosis kumatsimikizira kuti selo lililonse limalandira ma chromosome athunthu, omwe ndi ofunikira pakukula, kubereka, ndi kukonzanso minofu.
4. Kulamulira Majini: Momwe DNA imasungidwira mu nucleosomes zimakhudza kuthekera kwa majini kuonekera. Kusintha kwa mankhwala ku histones ndi DNA, monga methylation ndi acetylation, kungasinthe kupezeka kwa madera enaake a DNA, zomwe zimagwira ntchito ngati njira yofunika kwambiri yolamulira majini.
Kapangidwe ka Chromosome ndi Matenda
Kusokonezeka kwa kapangidwe kake kapena kuchuluka kwa ma chromosome kungayambitse matenda a majini. Matenda ena odziwika bwino ndi awa:
1. Down Syndrome: Imayamba chifukwa cha kopi yowonjezera ya chromosome 21 (trisomy 21).
2. Khansa: Kusintha kwa kapangidwe ka chromosome, monga kusintha kwa majini kapena kukulitsa majini, kungayambitse matenda a oncogene kapena kuletsa majini oletsa chotupa.
3. Matenda a Klinefelter: Amadziwika ndi kuchuluka kwa ma chromosome X imodzi kapena zingapo mwa amuna.
4. Matenda a Turner: Amayambitsidwa ndi monosomy X, pomwe mkazi ali ndi chromosome imodzi yokha ya X.
Kafukufuku Wamtsogolo M'munda wa Ma Chromosomu
Kafukufuku wowonjezereka wokhudza kapangidwe ka ma chromosome ndi ntchito yake ukufuna kuwunikira kwambiri matenda a majini ndi khansa, komanso kupeza njira zopangira njira zatsopano zochiritsira. Mwachitsanzo, kumvetsetsa ntchito ya kusintha kwa hysteresis mu malamulo a majini kwatsegula njira zatsopano zopangira mankhwala zomwe zingasinthe kapena kulunjika kusinthaku kuti kuchiritse matenda.
Mapeto
Kapangidwe ka ma chromosome mu nyukiliyasi ya eukaryotic ndi kapangidwe kovuta koma kokonzedwa bwino komwe kumatsimikizira kusungidwa, kufotokozedwa, ndi kusamutsa bwino kwa chidziwitso cha majini. Ma chromosome ndi zinthu zambiri kuposa DNA yokha; ndi zida zolondola za moyo, zomwe zimasonyeza kukhazikika kwa majini ndi kusinthasintha. Mwa kumvetsetsa ma chromosome, sitingotsegula zinsinsi za moyo komanso timatsegula njira yopitira patsogolo zachipatala ndi zamoyo mtsogolo.
