Izinhlobo zama-Chromosomes: Izisekelo ze-Biology yezakhi zofuzo
Ama-chromosome ayizakhiwo ezincane kakhulu ezitholakala ngaphakathi kwamaseli agcina ulwazi lwezakhi zofuzo olubalulekile ekukhuleni, ekuthuthukisweni, kanye nasekusebenzeni kwezinto eziphilayo. Ku-biology, ama-chromosome adlala indima ebalulekile futhi agxile kakhulu ekufundweni emkhakheni wezakhi zofuzo. Ukuqonda ama-chromosome kusho ukucwaninga ngolimi oluyisisekelo lokuphila. Lesi sihloko sizoxoxa ngezinhlobo ezahlukene zama-chromosome, imisebenzi yawo, kanye nokubaluleka kwawo ezintweni eziphilayo.
Incazelo kanye nesakhiwo sama-Chromosomes
Kuwo wonke amaseli e-eukaryotic, ama-chromosome atholakala kuyi-nucleus. Ama-chromosome akhiwa yi-DNA (i-deoxyribonucleic acid) kanye namaprotheni abizwa ngokuthi ama-histones. I-DNA iqukethe ulwazi lwezakhi zofuzo oluhlelwe lwaba izakhi zofuzo. Ngendlela ehlelekile kakhulu, i-DNA ende ihlanganiswe ngokuqinile kuma-chromosome, okuwavumela ukuthi angene ngaphakathi kwi-nucleus yeseli.
Njengoba amangqamuzana elungiselela ukuhlukana, ama-chromosome aba abalulekile. Ayaphindaphindeka, okuqinisekisa ukuthi iseli ngalinye lendodakazi lithola isethi ephelele yama-chromosome. Kubantu, isibonelo, kunezimbili zama-chromosome ezingu-23, okwenza ama-chromosome angu-46 esewonke. Isibili ngasinye sakhiwe yi-chromosome eyodwa ezuzwe kumama kanye nesinye esivela kubaba.
Izinhlobo zama-Chromosomes Ngokusekelwe Esimweni se-Centromere
Ama-chromosome angahlukaniswa ngokusekelwe endaweni ye-centromere, indawo lapho i-chromosome ihlukana khona ibe yizingalo ezimbili. Izindawo ezahlukene ze-centromere zithinta ukuma nokusebenza kwe-chromosome. Nazi ezinye izinhlobo zama-chromosome ngokusekelwe endaweni ye-centromere:
1. I-Metacentric
Ama-chromosome aphakathi nendawo ane-centromere etholakala cishe phakathi nendawo, ngakho izingalo ze-p ne-q cishe zilingana ngobude. Lawa ma-chromosome abonakala ngesimo "se-V" ngaphansi kwe-microscope ngesikhathi sokuhlukaniswa kwamaseli.
2. I-Submetacentric
Kuma-chromosome angaphansi kwe-metacentric, i-centromere ayikho phakathi nendawo, kodwa ishintshwa kancane iye ohlangothini olulodwa, okwenza ingalo eyodwa ibe yinde kunenye. La ma-chromosome abonakala enomumo "L".
3. I-Acrocentric
Lolu hlobo lune-centromere eseduze kakhulu nokuphela kwe-chromosome, okuholela engalweni eyodwa ende kakhulu kanye nengalo eyodwa emfushane kakhulu. Lokhu kungalingani kuvame ukuthinta indlela izakhi zofuzo ezivezwa ngayo.
4. I-Telocentric
Ama-chromosome e-telocentric ane-centromere yawo ekugcineni kwe-chromosome, ekhiqiza ingalo eyodwa kuphela. Kubantu, ama-chromosome e-telocentric awatholakali empeleni, kodwa atholakala kwezinye izinhlobo.
Izinhlobo zama-Chromosomes Ngokusekelwe Kumsebenzi
Ngaphandle kokusekelwe endaweni ye-centromere, ama-chromosome angahlukaniswa futhi ngokusekelwe emsebenzini wawo emzimbeni:
1. Ama-Chromosomes e-Autosomal
Ama-chromosome e-autosomal akha ama-pair okuqala angu-22 ama-chromosome omuntu. Awabandakanyeki ekunqumeni ubulili bomuntu, kodwa aphethe izakhi zofuzo ezahlukahlukene ezilawula imisebenzi eyahlukahlukene yezinto eziphilayo. Ukungalingani noma ukuguquka kwalezi zakhi zofuzo kungaholela ezifweni zofuzo ezizuzwe njengefa.
2. Ama-chromosome Ocansi
Ama-chromosome ocansi ayizimbili zama-chromosome kubantu, anomthwalo wokunquma ubulili. Abantu banezinhlobo ezimbili zama-chromosome ocansi: u-X no-Y. Abesifazane bavame ukuba nama-chromosome amabili e-X (XX), kuyilapho abesilisa bene-chromosome eyodwa ye-X neyodwa ye-Y (XY). Ukuba khona noma ukungabikho kwe-chromosome ye-Y kudlala indima ebalulekile ekuthuthukisweni kwezici zocansi zesibili.
Ukushintshashintsha kwe-Chromosome kanye nezinguquko
Ukuguquka kwezakhi zofuzo, noma ukuhlukahluka kwesakhiwo se-chromosome, kungenzeka, okungaba nomthelela omkhulu emvelweni. Kunezinhlobo eziningana zezinguquko ezibalulekile ze-chromosome:
1. Ukususwa (Ukulahlekelwa)
Kwenzeka lapho ingxenye ye-chromosome ilahleka noma isuswa, okungaholela ekulahlekelweni kwezakhi zofuzo ezibalulekile eyodwa noma ngaphezulu.
2. Ukukopisha
Kwenzeka lapho ingxenye ye-chromosome iphindaphindwa, okwenza ivele izikhathi ezingaphezu kwesisodwa ku-genome.
3. Ukuguqulwa
Izingxenye ze-chromosome ziyaguqulwa bese zifakwa kabusha ku-chromosome, okungaphazamisa ukubonakaliswa kwezakhi zofuzo kuleyo ndawo.
4. Ukufuduka
Ukushintshana kwezingxenye phakathi kwama-chromosome angewona awe-homologous. Lokhu kungabangela izinguquko ezinkulu ekuhleleni izakhi zofuzo, okuholela ezifweni noma ezinkingeni zofuzo.
5. I-Aneuploidy
Isimo lapho amaseli enenani elingajwayelekile lama-chromosome. Isibonelo, i-Down syndrome ibangelwa ukuba khona kwekhophi eyengeziwe ye-chromosome 21 (i-trisomy 21).
Izifundo ze-Chromosome kwezokwelapha nocwaningo
Ucwaningo lwama-chromosome luvule amathuba amaningi kwezokwelapha kanye nezakhi zofuzo. Ukuhlaziywa kwama-chromosome, okunye kwawo okwenziwa ngendlela eyaziwa ngokuthi i-karyotyping, kuhilela ukudaya ama-chromosome nokuwabona ukuthi awanakho yini ukukhubazeka kwesakhiwo noma ukusebenza kwawo.
Ukuhlolwa kwangaphambi kokubeletha kuvame ukwenziwa ukuze kutholakale ukukhubazeka kwe-chromosome embungwini, njenge-trisomy 21, ukuze kutholakale izinyathelo zokuvimbela kusenesikhathi. Ucwaningo lwezakhi zofuzo luhlanganisa nokutadisha ukuguquka kwe-chromosome kumdlavuza. Umdlavuza uvame ukuhambisana nokuguquka kwe-chromosome, okungathinta inkambo yesifo noma impendulo yesiguli ekwelashweni.
Isiphetho
Ama-chromosome adlala indima ebalulekile ekuzuzeni izakhi zofuzo kanye nokusebenza kwezinto eziphilayo. Ukuqonda izinhlobo zama-chromosome, kokubili ngokwesakhiwo kanye nomsebenzi, kunikeza ukuqonda okujulile ngebhayoloji yama-molecule kanye nezakhi zofuzo. Ama-chromosome abalulekile hhayi kuphela kubacwaningi nososayensi kodwa nakulabo abahilelekile kwezempilo, njengoba lolu lwazi lungasetshenziswa ekuxilongweni nasekwelapheni izifo zofuzo. Ngokuqhubeka kwentuthuko yobuchwepheshe kanye nocwaningo, ulwazi lwethu ngama-chromosome kanye nomthelela wawo empilweni luzoqhubeka lukhula, luvule umnyango wekusasa lezokwelapha elenziwe ngezifiso neliphumelelayo.
