Gawo la Chromosome: Kumvetsetsa Kapangidwe ka Majini ndi Ntchito Yake
Ma chromosome ndi zinthu zovuta zomwe zimapezeka mkati mwa nucleus ya maselo a eukaryotic. Amanyamula chidziwitso cha majini mu mawonekedwe a DNA ndi mapuloteni, zomwe zimagwira ntchito yofunika kwambiri pakufalitsa makhalidwe kuchokera ku mibadwomibadwo kupita ku mibadwomibadwo. Kuti timvetse momwe ma chromosome amagwirira ntchito, ndikofunikira kufufuza mozama zigawo zawo ndi momwe zimathandizira pa ntchito ya majini. M'nkhaniyi, tifufuza mbali zazikulu za ma chromosome, kuphatikizapo ma centromere, ma telomere, ma chromatids, ndi ena, ndi ntchito zawo.
Kapangidwe Koyambira ka Ma Chromosomu
Ma chromosome amapangidwa ndi DNA yozungulira mamolekyu a mapuloteni otchedwa histones, ndikupanga kapangidwe kotchedwa chromatin. Mu maselo a eukaryotic, ma chromosome amaonekera ndikukonzedwa panthawi ya kugawikana kwa maselo, mitosis ndi meiosis. Chromatin yofupikitsidwa imapanga ma chromatids, omwe amawoneka ngati ulusi wozungulira, ndipo chromosome iliyonse imakhala ndi ma chromatids awiri ofanana otchedwa ma chromatids alongo.
Centromere
Chimodzi mwa zigawo zofunika kwambiri za chromosome ndi centromere. Centromere ndi gawo la chromosome lomwe limagwira ntchito ngati malo omangira ma chromatids awiri alongo ndipo ndi malo olumikizirana a kinetochore. Kinetochore ndi kapangidwe ka mapuloteni ovuta komwe ulusi wa spindle umalumikizana nawo panthawi yogawa maselo, zomwe zimathandiza kuti ma chromatids alekanitsidwe bwino kukhala maselo aakazi.
Sentromere si nthawi zonse imakhala pakati pa chromosome; malo ake amatha kusiyana. Kutengera malo a centromere, ma chromosome amatha kugawidwa m'mitundu ingapo: metacentric (centromere pakati), submetacentric (centromere pamwamba pang'ono pakati), acrocentric (centromere pafupi ndi kumapeto), ndi telocentric (centromere kumapeto).
Telomer
Ma Telomere ndi malekezero a ma chromosome olunjika, opangidwa ndi ma DNA obwerezabwereza. Ma Telomere amateteza malekezero a ma chromosome kuti asawonongeke ndi kusakanikirana ndi ma chromosome ena. Nthawi iliyonse selo likagawanika, ma telomere amafupikitsidwa, zomwe zimagwirizanitsidwa ndi kukalamba kwa maselo ndi ukalamba wonse. Enzyme ya telomerase imatha kuwonjezera kutalika kwa ma telomere, kuchita gawo lofunika kwambiri m'maselo omwe ayenera kugawanika pafupipafupi, monga maselo oyambira ndi maselo a khansa.
Ma Telomere nawonso amachita gawo lofunika kwambiri pakuzindikira nthawi ya moyo wa maselo. Ma telomere akafupika kwambiri, maselo amalowa mu gawo lotchedwa ukalamba, komwe amasiya kugawikana koma amakhalabe ndi mphamvu zogwirira ntchito. Iyi ndi njira yofunika kwambiri yopewera kukula kosalamulirika kwa maselo ndi khansa.
Chromatid
Chromatidi ndi gulu lofanana la magawo awiri olunjika omwe amapanga chromosome yobwerezabwereza. Chromozomu isanagawidwe, imakhala ndi ma chromatid awiri olumikizidwa pamalo otchedwa centromere. Chromatidi iliyonse imakhala ndi kopi yeniyeni ya DNA, kuonetsetsa kuti selo lililonse la mwana limalandira majini onse ofunikira kuti ligwire bwino ntchito.
Manja a P ndi Q
Ma chromosome amatha kugawidwa m'magawo awiri akuluakulu otchedwa mikono. Mkono waufupi umadziwika kuti mkono wa P, pomwe mkono wautali umatchedwa mkono wa Q. Dzinali limachokera ku Chifalansa, ndipo 'petit' limatanthauza yaying'ono ya mkono wa P. Gawoli limathandiza kupanga mapu a ma chromosome ndikuzindikira komwe majini enaake ali.
Ukadaulo wosiyanasiyana wa mapu a chromosome, monga kuyika utoto ndi fluorescein in situ hybridization (FISH), umagwiritsa ntchito magawowa kuti udziwe bwino malo a majini kapena zolakwika mkati mwa majini. Izi ndizothandiza pakufufuza majini ndi kuzindikira matenda okhudzana ndi majini.
Ntchito ndi Kufunika kwa Ma Chromosomu
Ma chromosome samangonyamula majini okha, komanso amawongolera momwe majini amagwirira ntchito komanso amaonetsetsa kuti majiniwo ali olimba kudzera mu kugawikana kwa maselo kolamulidwa. Nazi zina mwa ntchito ndi kufunika kwa ma chromosome:
1. Kufalikira kwa majini: Ma chromosome amalola kuti zinthu za majini zilowe m'malo mwa mibadwo ina, zomwe zimathandiza kuti ana alandire chidziwitso cha majini chofunikira pakukula ndi kugwira ntchito.
2. Kulamulira Majini: Malo omwe majini ali pa ma chromosome ndi momwe amagwirira ntchito ndi mapuloteni a histone ndi owongolera ena zimakhudza momwe majini amagwirira ntchito. Kapangidwe ka chromatin kangakhale kakang'ono kapena kosasunthika, zomwe zimapangitsa kuti majini agwire ntchito kapena asagwire ntchito.
3. Kulamulira Kusiyanasiyana kwa Majini: Panthawi ya meiosis, zochitika monga kuwoloka ndi kusinthana kwa zinthu za majini pakati pa ma chromosome ofanana zimawonjezera kusiyanasiyana kwa majini, izi ndizofunikira pakusintha ndi kusintha.
4. Kukhazikika kwa majini: Kapangidwe ka mzere ndi kopindika ka ma telomere kumathandiza kuteteza chidziwitso cha majini panthawi yobwerezabwereza kwa DNA, kuteteza kuwonongeka kapena kutayika kwa chidziwitso cha majini.
Mapeto
Kumvetsetsa magawo a ma chromosome ndi ntchito zawo kumatithandiza kumvetsetsa bwino momwe majini amagwirira ntchito komanso momwe majini amagwirira ntchito m'zinthu zamoyo. Gawo lililonse la chromosome lili ndi gawo lapadera komanso lofunika kwambiri pakusunga umphumphu ndi kupitiriza kwa zinthu za majini, zomwe zimathandiza kuti zamoyo zikule, zikule, komanso kuberekana bwino. Kuyambira ma centromere mpaka ma telomere, gawo lililonse limagwira ntchito limodzi kuti litsimikizire kuti chidziwitso cha majini chikusungidwa ndikuwonetsedwa mwadongosolo, kugogomezera zodabwitsa ndi zovuta za moyo pamlingo wa microscopic. Kafukufuku wowonjezereka akupitilizabe kuvumbula zinsinsi zokhudza ma chromosome, zomwe zingathandize kumvetsetsa matenda a majini ndi njira zatsopano zochiritsira.
