Zitsanzo za Mafunso Okhudza Chimake cha Selo
Chitoliro cha selo ndi gawo lofunika kwambiri la maselo a eukaryotic, lomwe limagwira ntchito ngati malo olamulira ntchito za maselo. Chimasunga zinthu za majini a selo, monga DNA, yomwe imakonzedwa m'ma chromosome. Kumvetsetsa ntchito ndi kapangidwe ka chitoliro cha selo ndikofunikira kwambiri pophunzira za sayansi ya maselo ndi majini. M'nkhaniyi, tikambirana zitsanzo zingapo za mavuto okhudzana ndi chitoliro cha selo, ndi mafotokozedwe.
Chiyambi cha Selo la Mkati
Tisanafufuze mafunso a chitsanzo, tiyeni tikambirane mwachidule za selo. Thupi la selo lili ndi nembanemba ya nyukiliya, yomwe imailekanitsa ndi selo. Nembanemba iyi ili ndi zigawo ziwiri za lipid bilayer ndipo ili ndi ma pores a nyukiliya omwe amalola kusinthana kwa zinthu pakati pa selo ndi selo. Gawo limodzi lofunika kwambiri la selo ndi nucleolus, dera lomwe ma ribosome amapangidwa.
Ntchito zazikulu za selo la selo ndi monga kusunga chidziwitso cha majini, kubwerezabwereza kwa DNA, ndi kulemba kwa RNA. Lolani selo limayang'aniranso kayendedwe ka selo ndipo limagwira ntchito yofunika kwambiri pakugawikana kwa selo.
Chitsanzo cha Funso 1
Funso: Fotokozani ntchito ya nembanemba ya nyukiliya pa ntchito ya selo.
Kukambirana:
Nembanemba ya nyukiliya, yomwe imadziwikanso kuti envelopu ya nyukiliya, imakhala ndi zigawo ziwiri za nembanemba ya lipid bilayer yomwe imalekanitsa zomwe zili mu nyukiliya (nucleoplasm) ndi cytoplasm. Nembanemba ya nyukiliya imagwira ntchito ngati chotchinga chosankha chomwe chimayang'anira kusinthana kwa zinthu pakati pa nyukiliya ndi cytoplasm, monga RNA, mapuloteni, ndi ma nucleotide.
Ma pores a nyukiliya omwe ali mu nembanemba iyi amagwira ntchito yofunika kwambiri pa kunyamula mamolekyu. Mwachitsanzo, mamolekyu a RNA omwe amapangidwa mu nembanemba ayenera kutuluka mu cytoplasm kuti asinthidwe kukhala mapuloteni. Mosiyana ndi zimenezi, mapuloteni ofunikira pa ntchito ya nyukiliya, monga enzyme ya DNA polymerase, ayenera kulowetsedwa mu nembanemba. Motero, nembanemba ya nyukiliya imasunga malo amkati mwa nembanembayo ndikuonetsetsa kuti kulumikizana pakati pa nembanembayo ndi cytoplasm kukuyenda bwino.
Chitsanzo cha Funso 2
Funso: Kodi tanthauzo la nucleolus ndi chiyani ndipo ntchito zake ndi ziti?
Kukambirana:
Nucleolus ndi kapangidwe kamene kamapezeka mkati mwa selo lomwe silili ndi nembanemba ndipo limawoneka lakuda pansi pa maikulosikopu. Ndi malo oyambira kupanga ribosome, organelle yomwe imagwira ntchito popanga mapuloteni.
Ntchito yaikulu ya nucleolus ndi kulemba kwa ribosomal RNA (rRNA), yomwe kenako imaphatikizidwa ndi mapuloteni a rRNA kuti apange ma ribosomal subunits. Ma subunits awa amasamutsidwa kupita ku cytoplasm, komwe amasonkhanitsidwa kukhala ma ribosome ogwira ntchito.
Kuwonjezera pa ntchito yake pakupanga ribosome, nucleolus imathandizanso pakuwongolera kayendedwe ka maselo, kusintha mayankho a kupsinjika, komanso kukonza DNA. Chifukwa chake, nucleolus imagwira ntchito yofunika kwambiri pakusunga thanzi la maselo ndi kugwira ntchito kwawo.
Chitsanzo cha Funso 3
Funso: Kodi chromatin imagwira ntchito bwanji pakulamulira majini mu nyukiliyasi ya selo?
Kukambirana:
Chromatin ndi gulu la mapuloteni a DNA ndi histone omwe amapezeka mu selo. Mu selo la maselo a eukaryotic, DNA simapezeka mu unyolo wautali koma m'malo mwake ndi kapangidwe kakang'ono, kokonzedwa bwino kotchedwa chromatin. Pali mitundu iwiri ikuluikulu ya chromatin: euchromatin ndi heterochromatin.
Euchromatin ndi mtundu wotseguka komanso wogwira ntchito molemba, zomwe zikutanthauza kuti majini omwe ali mu euchromatin amapezeka mosavuta kuti alembedwe mu RNA kenako nkusinthidwa kukhala mapuloteni. Mosiyana ndi zimenezi, heterochromatin ndi mtundu wocheperako ndipo nthawi zambiri sagwira ntchito molemba molemba molemba.
Kuwongolera kapangidwe ka chromatin kumachita gawo lofunika kwambiri pakulamulira kagwiritsidwe ntchito ka majini. Njira monga methylation ya DNA ndi kusintha kwa histone zimatha kusintha kapangidwe ka chromatin motero zimakhudza kupezeka kwa majini ku zinthu zolembera. Izi zimathandiza maselo kuwongolera majini molondola malinga ndi zosowa zawo.
Chitsanzo cha Funso 4
Funso: Kodi n’chiyani chimachitika ku selo panthawi yogawa maselo, makamaka mu mitosis?
Kukambirana:
Pa nthawi yogawa maselo, makamaka mitosis, selo limadutsa mu kusintha kotsatizana. Njirayi ingagawidwe m'magawo angapo:
1. Prophase: Chromatin imasungunuka kukhala ma chromosome omwe amawoneka pansi pa maikulosikopu yowala. Chromosome iliyonse imakhala ndi ma chromatids awiri alongo olumikizidwa pa centromere. Nucleolus imayamba kugwira ntchito ndipo nembanemba ya nyukiliya imayamba kusweka.
2. Prometaphase: Nembanemba ya nyukiliya imasweka pafupifupi kwathunthu, zomwe zimapangitsa kuti microtubule spindle igwirizane ndi kinetochores zomwe zili pa centromeres ya chromosome iliyonse.
3. Metaphase: Ma chromosome amatsagana m'mbali mwa equator ya selo, yotchedwa metaphase plate. Izi zimatsimikizira kuti selo lililonse la mwana wamkazi limalandira kopi yofanana ya zinthu za majini.
4. Anaphase: Ma chromatids alongo amalekanitsidwa ku mbali zosiyana za selo, zomwe zimayendetsedwa ndi kufupikitsa kwa ma microtubules.
5. Telophase: Gulu lililonse lolekanitsidwa la ma chromatids tsopano lili mbali zosiyana za selo ndipo limabwereranso ku chromatin. Nembanemba ya nyukiliya imayamba kupangidwa mozungulira gulu lililonse la chromatin, ndikupanga ma nuclei awiri aakazi.
6. Cytokinesis: Njirayi imaphatikizapo kugawikana kwa cytoplasm, zomwe zimapangitsa kuti maselo awiri osiyana a mwana aliyense akhale ndi nucleus yakeyake.
Pa nthawi ya mitosis, kusweka ndi kupangidwanso kwa nembanemba ya nyukiliya ndikofunikira kuti zitsimikizire kuti majini afalikira mofanana ku maselo aakazi.
Mapeto
Kumvetsetsa bwino kapangidwe ndi ntchito ya selo, pamodzi ndi njira zomwe zimayenderana nayo, ndikofunikira kwambiri mu sayansi ya maselo ndi mamolekyu. Kudzera mu mndandanda wa mavuto ndi zokambirana zomwe zili pamwambapa, titha kuwona momwe selo limagwirira ntchito ngati malo owongolera, kusunga zinthu za majini ndikuwongolera ntchito za maselo. Chidziwitsochi sichimangothandiza kuphunzira zoyambira za sayansi ya maselo komanso chimakhudza kwambiri kafukufuku wazachipatala, kuphatikizapo kumvetsetsa njira zomwe matenda a majini amagwirira ntchito komanso kupanga njira zochiritsira majini.
