Wāhanga Ira Ira: Te Mārama ki te Hanganga me te Mahi Ira
He hanganga matatini ngā ira-kōmiro kei roto i te pūtake o ngā pūtau eukaryotic. Kei a rātou ngā mōhiohio ira i roto i te āhua o te DNA me ngā pūmua, ā, he mahi nui tā rātou ki te tuku i ngā āhuatanga mai i tētahi whakatipuranga ki tētahi whakatipuranga. Hei mārama ki te mahi a ngā ira-kōmiro, he mea nui kia ruku hohonu atu ki roto i ō rātou wāhanga me te whai wāhi atu ki te mahi ira. I roto i tēnei tuhinga, ka tūhuratia e mātou ngā wāhanga matua o ngā ira-kōmiro, tae atu ki ngā centromere, ngā telomere, ngā chromatids, me ētahi atu, me ā rātou mahi.
Hanganga Taketake o ngā Chromosome
Ko ngā ira-kōromomā he mea hanga mai i te DNA e takai pūmau ana i ngā ngota pūmua e kiia nei ko ngā histone, e hanga ana i tētahi hanganga e mōhiotia ana ko te chromatin. I roto i ngā pūtau eukaryotic, ka kitea, ka whakaritea hoki ngā ira-kōromomā i ngā wāhanga o te wehenga pūtau, te mitosis me te meiosis. Ka hangaia e ngā ira-kōromomātā kua whakapotohia ngā ira-kōromomā, he rite ki ngā miro takai, ā, e rua ngā ira-kōromomā ōrite o ia ira-kōromomāmā e kiia nei ko ngā ira-kōromomāmā tuahine.
He pokapū
Ko tētahi o ngā wāhanga tino nui o te irahiko ko te centromere. Ko te centromere te wāhanga o te irahiko e mahi ana hei pūwāhi punga mō ngā irahiko tuahine e rua, ā, koinei hoki te wāhi e piri ai te kinetochore. Ko te kinetochore he hanganga pūmua matatini e piri ai ngā muka porowhita i te wā e wehea ana te pūtau, e āwhina ana i te wehenga tika o ngā irahiko ki ngā pūtau tamāhine.
Kāore te pokapū o te ira tangata e noho tonu ana i waenganui o te ira tangata; ka rerekē pea tōna tūranga. I runga i te tūranga o te pokapū, ka taea te whakarōpū i ngā ira tangata ki ētahi momo: metacentric (te pokapū o te ira tangata kei waenganui), submetacentric (te pokapū o te ira tangata kei runga ake i te pokapū), acrocentric (te pokapū o te ira tangata e tata ana ki te pito), me te telocentric (te pokapū o te ira tangata kei te pito).
Telomera
Ko ngā telomere ngā pito o ngā ira-kōromōne rārangi, he mea tito mai i ngā raupapatanga ira-kōromōne auau. Ka tiakina e ngā telomere ngā pito o ngā ira-kōromōne mai i te pirau me te hanumi ki ētahi atu ira-kōromōne. I ia wā ka wehea he pūtau, ka whakapotohia ngā telomere, e pā ana ki te koroheketanga pūtau me te koroheketanga whānui. Ka taea e te whākōkī telomerase te whakanui ake i te roa o te telomere, e whai wāhi nui ana ki ngā pūtau me wehe pinepine, pērā i ngā pūtau take me ngā pūtau matepukupuku.
He mahi nui anō tā ngā telomere ki te whakatau i te roa o te ora o te pūtau. Ina poto rawa ngā telomere, ka uru ngā pūtau ki tētahi wāhanga e mōhiotia ana ko te koroheketanga, ka mutu te wehewehe engari ka noho kaha tonu te pākia o te tinana. He tikanga nui tēnei hei ārai i te tipu pūtau kāore i te whakahaeretia me te mate pukupuku.
Chromatid
He huinga ōrite o ngā wāhanga rārangi e rua te chromatid e hanga ana i tētahi chromosome kua tāruatia. I mua i te wehenga pūtau, e rua ngā chromatid e honoa ana ki tētahi rohe e kiia nei ko te centromere. Kei roto i ia chromatid he tārua tika o te DNA, kia whiwhi ai ia pūtau tamahine i te rauemi ira katoa e hiahiatia ana mō te mahi noa.
Ngā ringa P me Q
E rua ngā wāhanga matua o ngā ira-ira, arā, ko ngā ringaringa. Ko te ringaringa poto ko te ringaringa P, ko te ringaringa roa ko te ringaringa Q. Nō te reo Wīwī tēnei ingoa, ko te tikanga o te kupu 'petit' he iti mō te ringaringa P. Mā tēnei wehenga ka taea te mahere i ngā ira-ira me te tautuhi i te wāhi o ngā ira motuhake.
Mā ngā hangarau mahere ira, pērā i te tae whitiki me te whakamomona fluorescein in situ (FISH), ka whakamahia ēnei wehenga hei tautuhi tika ake i te wāhi o ngā ira, ngā hapa rānei i roto i te ira. He mea whai hua tēnei i roto i te rangahau ira me te tautuhi i ngā āhuatanga e pā ana ki te ira.
Te Mahi me te Hiranga o ngā Chromosome
Ehara i te mea ko ngā ira anake te kawenga a ngā ira-pūtau; engari ka whakahaere anō hoki i te whakaaturanga ira me te whakarite i te pumau o ngā ira mā te whakahaere i te wehenga pūtau. Anei ētahi o ngā mahi me te hiranga o ngā ira-pūtau:
1. Te Tuku Ira: Mā ngā ira-ira ka taea te tuku iho i ngā rauemi ira mai i tētahi whakatipuranga ki tētahi whakatipuranga, kia whiwhi ai ngā uri i ngā mōhiotanga ira e tika ana mō te whanaketanga me te mahi.
2. Te Whakahaere Ira: Ko te taunga o ngā ira i runga i ngā chromosome me ā rātou taunekeneke ki ngā pūmua histone me ētahi atu kaiwhakahaere ka pā ki te whakaaturanga ira. Ka taea e te hanganga chromatin te kiato ake, te wetewete ake rānei, e whakatau ana mēnā he ira hohe, he ira kore mahi rānei.
3. Te Whakahaere i te Kanorau Ira: I te wā o te meiosis, ka whakanui ake ngā kaupapa pēnei i te whakawhiti me te whakawhiti rauemi ira i waenga i ngā chromosome homologous i te kanorau ira, he mea nui tēnei mō te whanaketanga me te urutau.
4. Te Pūmautanga o te Ira: Mā te hanganga rārangi me te piko o ngā telomere ka āwhina i te tiaki i ngā mōhiohio ira i te wā o te tukanga tāruarua DNA, ka ārai i te kino, i te ngaronga rānei o ngā mōhiohio ira.
Whakamutunga
Mā te mārama ki ngā wāhanga o ngā ira-kōromō me ā rātou mahi ka kitea he māramatanga hohonu ake ki ngā tikanga tuku iho me ngā whanaketanga ira i roto i ngā rauropi. He mahi motuhake, he mahi nui hoki tā ia wāhanga o te ira-kōromō ki te pupuri i te pono me te haere tonu o ngā rauemi ira, kia taea ai e ngā rauropi te tipu, te whanake, me te whakaputa uri whai hua. Mai i ngā centromere ki ngā telomere, ka mahi tahi ia wāhanga ki te whakarite kia mau tonu, kia whakapuakina hoki ngā mōhiohio ira i roto i te tikanga tika, me te whakanui i te mīharo me te uaua o te ora i te taumata moroiti. Kei te haere tonu ngā rangahau ki te hura i ngā mea ngaro mō ngā ira-kōromō, ka āwhina pea i tō tātou māramatanga ki ngā mate ira me ngā rongoā hou pea.
