Isakhiwo wama-chromosomes - esematheni zocwaningo amashumi eminyaka ezayo.

Kuze kube manje, izici kwezakhi zezinto ayisihloko locwaningo izazi zezinto eziphilayo-ososayensi emhlabeni, kungukuthi wafunda ngokugcwele. Nsuku zonke amaqiniso ezintsha nezithakazelisayo. Ngobuchwepheshe ethuthukisiwe, izindlela kohlaziyo kanye nemishini yesimanje, bonke ososayensi zijule zidlule izimfihlakalo uhlelo chromosomal, ukutadisha ukwakheka kwama-molecule futhi supramolecular yayo.

Nokho, namuhla, abantu abaningi baye kuningi eselikuzuzile wokucwaninga ngezakhi zofuzo wezinto ezincane eziphilayo. Umuntu ngamunye nesithakazelo, ukuvula incwadi, ungakwazi ukufunda isakhiwo chromosome, isakhiwo sabo futhi zisebenza vivo. Mayelana-ke kanye nenkulumo. Ngu uhlobo olunjani lwesakhiwo se-chromosome zihlukaniswe zibe:

• telotsentrichnye,
• akrotsentrichnye,
• submetacentic,
• metatsentrichnye.

Telotsentrichnye kukhona induku okwenyanga futhi aqukethe centromere, okuyinto evela izindikimba ezimbili. Akrotsentrichnye futhi akheke induku-like, kodwa munye "ingalo" amancane yabo, cishe imperceptible. (Ihlombe - ingxenye chromosome, okuyinto iza kolunye uhlangothi centromere). isakhiwo Submetatsenrichnoe kuyinto chromosome nge izingalo eside noma esifushane. Futhi metatsentrichnomu isakhiwo uhlobo kukhona Ama-chromosomes e ezimise-V, okuyizinto ngobude emahlombe okufanayo.

Ngokuvamile ama-chromosome bezyadernyh eziphilayo, kuhlanganise amagciwane namagciwane
I-chromosomes zisifake ngamunye luyingxenye ngabanye. Isakhiwo chromosome of amagciwane nezinye izinhlobo ulwelwe iyona elula kunazo. I-chromosome webhaktheriya yakhiwa nqunu kabili balahleke DNA uhlobo okungase komugqa noma annular. Isakhiwo apharathasi chromosome zamagciwane sihluke webhaktheriya molecule e-DNA. Ngokwesibonelo, ubude molecule ye-DNA igciwane kuhluka kumuntu ukuba eziyikhulu namashumi micrometer, bacterium DNA ifinyelela ubude micrometer ayizinkulungwane ezimbili. Split, ie synthesis molecule osizayo (ukufanisana) amagciwane wama-chromosomes iqala komunye yokuqalisa bese uya kanye ubude balo lonke, futhi amagciwane ke uya zombili izinkomba kusukela ukuqala, lapho izimfoloko ezimbili uhlukanise DNA kwakhiwa. Chromosome igciwane equkethe RNA kuyinto i-molecule elilodwa RNA ngesimo intambo, nakuba phakathi kwabo kukhona dvuhnitchatye-molecule. On ubukhulu chromosome lincane kakhulu kunalezo equkethe DNA.

Ama-chromosomes e eziphilayo yenuzi
Isakhiwo chromosome yeseli eukaryotic kokuba i-nucleus, kubhekwa enye yezinto ezinzima kakhulu. Kusekelwe phezu komugqa DNA of ubude eside, okungaba kuze 5 cm! izimo ezinjalo zingatholakala ngokutadisha isakhiwo chromosome womuntu. Ngaphandle molecule ye-DNA zimumethe chromosome ezikhethekile amaprotheni - histones. Bayisihlanu: H1, H2A, H3, H4 - kukhona amaprotheni main. Ngaphandle kwabo-molecule yakhiwa amaprotheni negistonnye. Isakhiwo wama-chromosomes eukaryotic kunzima kakhulu futhi kuthatha ifomu lobuhlalu.

Kunezinhlobo eziningana wama-chromosomes, okuyizinto bungavami. Lezi zihlanganisa i-chromosome giant polytene chromosome futhi chromosome lampbrush.

• Ama-chromosomes e-Giant kuhluke osayizi omkhulu. Betholakala khona emazingeni athile lomjikelezo iseli - kwesikhathi sokuphila esiphakathi cell ukwahlukana. Atholakala emangqamuzaneni athile izibungu isinambuzane, kanye yezilwane ezinomgogodla ezingenamgogodla.

• Polytene-chromosomes kukhona amaningi ingane imicu ukuthi ukhulise kusukela umzali semali, kodwa akazange azinze esizweni ngendlela kunezinxushunxushu futhi zenziwe Kuvunguza olulodwa. Basuke eziqukethwe emangqamuzaneni izibilini eziphilayo, isibonelo, amaseli emathunjini we fat umzimba, izindlala salivary, kuqhoqhoqho. Polytene-chromosomes futhi kungatholakala izitsha izibungu izinambuzane ezimbili ezinamaphiko.

• Ngokuvamile ama-chromosome lampbrush - a-chromosomes giant, isikhathi eside kunaleso polytene, okuyinto atholakala oocytes (Iqanda amaseli) yezilwane ezinomgogodla. Ukwakheka lampbrush Ama-chromosomes e sibonisa inani elikhulu angusayizi ohlukile futhi ubude amathebhu uhlangothi, lapho i-RNA zamagama kwenzeka.

Njengoba ubona, eziningi izinhlobo chromosome. Kuzo zonke izinto eziphilayo zihluke. Futhi Into ezithakazelisayo kakhulu ukuthi indlela zalesi simiso yamangqamuzana Namanje hhayi wafunda kuze kube sekupheleni. Isakhiwo-chromosome, inombolo, isakhiwo kanye ukwephulwa yayo kuholela ngokuguqula izakhi eziphilayo - konke lokhu evulekile sihloko zofuzo.