Ngā Tauira Pātai e Matapaki ana i te Hanganga o ngā Chromosome i roto i te Nucleus Eukaryotic
He wāhanga nui te hanganga o te ira tangata o te koiora pūtau, e whakaatu ana i te āhua o te penapena, te tuku, me te whakapuakitanga o ngā mōhiohio ira i roto i ngā eukaryote. I roto i tēnei tuhinga, ka whakamāramahia e mātou ngā ariā taketake o te hanganga o te ira tangata i roto i te karihi eukaryotic, me te whakarato tauira raruraru me ngā otinga hei āwhina i tō māramatanga.
He Kupu Whakataki ki te Hanganga o te Chromosome i roto i te Eukaryotic Nucleus
He hanganga āhua tokotoko ngā ira-kōpiko kei roto i te pūtake o ngā pūtau eukaryotic. He mea tito ēnei i te DNA me ngā pūmua e kiia nei ko ngā histone. He mahi nui tā ēnei hanganga ki te whakarite kia tika te tārua me te tuku iho i ngā mōhiohio ira i te wā o te wehenga pūtau. I roto i ngā ira-kōpiko, ka takai, ka takai te DNA i ngā histone, ka hanga he hanganga e mōhiotia ana ko ngā ira-kōpiko. Ka takai, ka takai anō ēnei ira-kōpiko hei hanga i te ira-kōpiko kiato ake, inā koa i te wā o te wehenga pūtau.
Hanganga Taipitopito o ngā Chromosome
1. Te DNA me ngā Nucleotides: He mekameka roa o ngā nucleotides te DNA e hanga ana i te waehere ira. Ko ngā nucleotides he huka deoxyribose, he rōpū phosphate, me tētahi o ngā turanga hauota e whā: adenine (A), thymine (T), guanine (G), me te cytosine (C).
2. Ngā Histone: Ka mahi ēnei pūmua hei "pōkai" e takai ai te DNA. E rima ngā momo histone e whai wāhi ana ki te hanganga o te nucleosome: H1, H2A, H2B, H3, me te H4.
3. Nukleosome: Koinei te waeine taketake o te whakaritenga o ngā ira, he wāhanga poto o te DNA e takai ana i te matua histone.
4. Chromatin: Ka piri tahi ngā nucleosome tāruarua hei hanga i tētahi hanganga e mōhiotia ana ko te chromatin. E rua ngā āhua o te chromatin: he heterochromatin (kiato, kāore e mahi) me te euchromatin (ngāwari, ā, he kaha te whakaputanga).
5. Ngā Chromatid Tuahine: Ina puta te tāruaruatanga o te DNA, ka puta i ia chromosome ngā tārua e rua e mōhiotia ana ko ngā chromatid tuahine, e honoa ana i waenganui e tētahi hanganga e kiia nei ko te centromere.
Ngā Tauira Pātai me ngā Kōrerorero
Pātai 1:
Whakamāramahia ngā rerekētanga matua i waenga i te chromatin me ngā chromosome.
Kōrero:
Ko te chromatin me ngā chromosome he momo ira rerekē e rua e uru ana ki te tuku iho. Ko te chromatin te momo DNA wetekina, kāore i te whiria, e kitea ana i te wā o te huringa pūtau, e āhei ai te tuhi me te tāruarua i te DNA. He rerekē, ko ngā chromosome te momo chromatin kua whakapotohia e kitea ana i te wā o te mitosis me te meiosis; mā tēnei ka māmā ake te tohatoha tika o ngā rauemi ira ki ngā pūtau tamahine. Ko te rerekētanga matua kei roto i te nui o te whakapoto me te mahi i te wā o te huringa pūtau.
Pātai 2:
He aha te pānga o te hanganga histone ki te takai DNA i roto i te karihi o ngā pūtau eukaryotic?
Kōrero:
He mahi nui tā ngā histones ki te tākai me te whakarite i te DNA i roto i te karihi pūtau. He kino te utu o te DNA (nā te phosphate), engari he tino pai ngā histones nā te nui o te lysine me te arginine. Mā tēnei hononga ka taea e te DNA te takai pūmau ki te karihi histone, ka hanga te hanganga nucleosome. Ki te kore he histones, ka uaua te noho o te DNA roa, pakarukaru ki roto i ngā pūtau, ā, ka uaua hoki te mahi pai. Ka taea hoki e ngā histones te whakarerekē i ngā matū (pēnei i te acetylation me te methylation), ka pā ki te urunga o te DNA ki te tuhi me te tāruarua.
Pātai 3:
He aha te mahi a te centromere i roto i te wehenga pūtau, ā, he aha i hiranga ai?
Kōrero:
He wāhanga nui te centromere o te chromosome e mahi ana hei pūwāhi piri mō ngā pūmua motuhake e kiia nei ko ngā kinetochores i te wā o te wehenga pūtau. Ko ngā kinetochores ngā wāhi piri mō ngā muka microtubule e kawe ana i ngā chromatids tuahine ki ngā pou rerekē o te pūtau wehewehe. He mea nui te tūranga tika o te centromere me te hanganga kinetochore whai hua mō te tohatoha tika o ngā chromosome me te ārai i te aneuploidy, he āhuatanga kei roto i ngā pūtau he maha rerekē o ngā chromosome, ka arahi pea ki ngā mate ira.
Pātai 4:
He aha i kiia ai ko te euchromatin he mea nui ake i te tukanga whakawhiti ira i te heterochromatin?
Kōrero:
E kiia ana ko te Euchromatin he mea nui ake i roto i te whakawhitiwhiti kōrero nā te mea he ngoikore ake tōna hanganga i te heterochromatin, e māmā ake ai te uru atu o ngā whākōkī whakawhitiwhiti kōrero ki te DNA. Ko te mahi matua o te euchromatin ko te whakaatu i ngā ira e tika ana mō ngā mahi pūtau o ia rā. He rerekē, ko te heterochromatin kei roto i ngā ira kāore e mahi, kāore rānei e hiahiatia ana i ngā wā katoa, ā, he iti ake te kikī hei ārai i te whakawhitiwhiti kōrero. Ko te tikanga, he rohe ira kaha ake te whakawhitiwhiti kōrero a te euchromatin.
Pātai 5:
He aha te pānga o ngā whakarerekētanga histone ki te whakaaturanga ira? Homai he tauira o tētahi o ēnei whakarerekētanga.
Kōrero:
Ka pāngia te whakaaturanga ira e ngā whakarerekētanga histone mā te whakarerekē i te hanganga chromatin me te urunga o te ira ki te mīhini whakawhiti ira. Ko tētahi tauira ko te acetylation histone, e tāpirihia ana he rōpū acetyl ki te toenga lysine i runga i te hiku histone. Ka whakaitihia e tēnei whakarerekētanga te utu pai o te histone, ka ngoikore te taunekeneke i waenga i ngā histone me te DNA, ā, ka hua ake he hanganga chromatin tuwhera ake. Ka whakanui ake tēnei i te urunga o te DNA ki ngā take whakawhiti ira me ngā RNA polymerases, ā, ka whakarei ake i te whakaaturanga ira.
Whakamutunga
He mea nui te mārama ki te hanganga me te mahi a ngā ira-kōromō i roto i ngā pūtau eukaryotic ki ngā rangahau matatau i roto i te koiora ngota me te ira. Kua hangaia tēnei raruraru matapaki hei whakarei ake i te māramatanga o ngā ākonga me ngā kairangahau ki te āhua o te penapena me te whakarite a ngā rauropi i ngā mōhiohio ira, me te pēhea hoki e taea ai e ngā huringa o tēnei hanganga te whai wāhi ki ngā āhuatanga koiora me ngā mate.
