Mene ne wani chromosome? Saita na chromosomes. A biyu daga chromosomes

Gadar hali da kuma canzawa a cikin yanayi lumana domin chromosomes, kwayoyin halitta, deoxyribonucleic acid (DNA). Stores da kuma watsa kayyade bayani a cikin wani nau'i na sarƙoƙi na nucleotides a DNA. Wace rawa a wannan sabon abu nasa ne da kwayoyin halittu? Mene ne wani chromosome cikin sharuddan watsa hereditary halaye? Amsoshin wadannan tambayoyi zai fahimci ka'idojin coding kuma bambancin kwayoyin a wannan duniya tamu. Don babban har ya dogara kan yadda yawa chromosome shiga cikin sa, daga recombination daga wadannan sifofi.

Daga cikin tarihi na bude na "gadar hali barbashi"

Karatu a karkashin madubin da Kwayoyin tsirrai da dabbobi, da yawa botanists da Dabbobi har yanzu a tsakiyar XIX karni, kusantar da hankali ga mafi kyau zaren, kuma mafi karami annular tsarin a cikin nucleus din. More sau da yawa fiye da sauran chromosomes kira wani majagaba na Jamus anatomist Walther Flemming. Wannan ya yi amfani da aniline dyes don aiki na nukiliya Tsarin. Fleming ya gano wani abu da ake kira "chromatin" domin da ikon batawa. Kalmar "chromosome" a 1888 mini iso, a cikin kimiyya da juyin juya halin Genrih Valdeyer.

A lokaci guda Flemming aka neman amsa ga tambaya na abin da wani chromosome, da Belgium Edouard Van Beneden. A kadan baya da Jamus halitta Theodor Boveri da Eduard Strasburger gudanar da wani jerin gwaje-gwajen a tabbatar da ainihi na chromosomes, da haƙuri da su lambar a jinsuna daban na rayayyun kwayoyin halitta.

Fage chromosomal ka'idar gadar hali

American masanin Walter Sutton samu daga nawa chromosomes samu a cikin cell tsakiya. Kimiyya ĩmãni wadannan Tsarin dako raka'a gadar hali, jiki halaye. Sutton gano cewa chromosomes kunshi kwayoyin halitta, ta hanyar abin da aka wuce daga iyaye zuwa zuriyarsa dũkiyarsu da kuma ayyuka. Jini a cikin wallafe bayyana chromosome nau'i-nau'i, su motsi a lokacin da rabo daga cikin cell tsakiya.

Ko da kuwa da American abokan aiki, aiki a cikin shugabanci da ya jagoranci Theodor Boveri. Dukansu masu bincike a cikin ayyukan karatu al'amurran da suka shafi na canja wuri da hereditary dabiu, tsara ainihin tanadi a kan rawar da chromosomes (1902-1903). Kara ci gaba da ka'idar Boveri-Sutton ya faru a cikin dakin gwaje-gwaje na Nobel Thomas Morgan. Fitattun American halitta da kuma tawagar sun kafa jerin dokoki na ajiye da genes a kan chromosome, mun ɓullo da cytological dalilin bayanin inji daga cikin dokokin Gregor Mendel - da kafa mahaifin halittar jini.

A chromosomes a cikin cell

Bincike na tsarin chromosomes fara bayan da aka gano da kuma bayanin irin XIX karni. Wadannan corpuscles kuma filaments kunshe ne a cikin prokaryotic kwayoyin (maras makaman nukiliya) da kuma eukaryotic sel (a cikin nucleus din). Karatu a karkashin madubin bayyana cewa chromosome ne morphological ra'ayi. Wannan mobile filamentous jiki, wanda shi ne discernible a wasu bulan na cell sake zagayowar. A gaba dayan girma daga cikin Interphase tsakiya chromatin bautar. A wasu lokuta rarrabe chromosome a daya ko biyu chromatids.

Better gani wadannan tsarin a lokacin cell division - mitosis ko meiosis. A eukaryotic Kwayoyin sau da yawa za su iya tsayar da manyan chromosomes a mikakke tsari. A prokaryotes, su ne karami, ko da yake akwai ban. Sel sau da yawa sun hada da fiye da daya irin chromosomes, misali nasu kananan "barbashi gado" ne a mitochondria da chloroplast.

fom chromosomes

Kowane chromosome yana da wani tsarin da mutum, daban-daban daga wasu batawa halaye. A cikin nazarin ilimin halittar jiki ne da muhimmanci a ƙayyade matsayi na centromere, da tsawon da kuma jeri na makamai dangi zuwa ga kugu. A sa na chromosomes mafi yawa ana hada da wadannan siffofin:

• metacentric ko-daidai, halin da tsakiyar wurin da centromere.
• submetacentric ko neravnoplechie (constriction an biya diyya ga daya daga telomers).
• acrocentric, ko sanda-dimbin yawa, a cikin abin da centromere aka located kusan a karshen chromosomes.
• na nuna da wuya definable siffar.

chromosome aiki

Chromosomes an hada da genes - da aikin raka'a gadar hali. Telomeres - da iyakar da chromosome makamai. Wadannan qware abubuwa bauta domin neman kariya daga lalacewa, antiblock, niƙaƙƙun gaɓãɓuwa. Centromere aikin ta ɗawainiya da cire tallafin da chromosomes. Yana yana da wani kinetochore, shi ne don shi saka dogara sanda tsarin. Kowane biyu daga chromosomes ne mutum a wurin location da centromere. Filaments aiki dogara sanda haka da cewa 'yar Kwayoyin kara a kan daya chromosome, amma ba duka biyun ba. Uniform maimaitawan a fission tsari na samar da asalin na kwafi. Kwafi na kowane chromosome fara lokaci guda a dama wurare irin wannan cewa markedly accelerates da dukan tsari na rarraba.

Aikin na DNA da RNA

Don gano abin da wani chromosome, wanda shine aiki da wannan nukiliya tsarin kasa bayan karatu ta biochemical abun da ke ciki da kuma dukiyoyinsu. A eukaryotic Kwayoyin, makaman nukiliya chromosomes an kafa ta Fused abu - chromatin. Bisa ga bincike, shi kunshi high kwayoyin nauyi kwayoyin abubuwa:

• Deoxyribonucleic acid (DNA).
• ribonucleic acid (RNA).
• histone sunadaran.

Nucleic acid suna shan wani kai tsaye sashi a cikin biosynthesis na amino acid da sunadaran da cewa samar da watsa hereditary halaye daga tsara zuwa tsara. DNA na dauke a cikin nucleus din eukaryotic Kwayoyin, RNA da aka mayar da hankali a cytoplasm.

genes

X-ray bincike ya nuna cewa DNA Forms biyu karkace, wanda ya kunshi sarkar na nucleotides. Suna wakiltar wani carbohydrate deoxyribose, phosphate kungiyar da kuma daya daga cikin hudu nitrogenous sansanonin:

1. A - adenine.
2. G - Bibyun.
3. T - taimain.
4. C - saitosin.

Kuri'a dezoksiribonukleoproteidnyh helical filaments - a genes dauke da lamba bayanai game da jerin amino acid a cikin sunadaran ko RNA. A lokacin multiplication na hereditary halaye daga iyaye zuwa zuriya yana daukar kwayar cutar a cikin nau'i na gene alleles. Su sanin da aiki, girma da kuma ci gaban da wani musamman kwayoyin. A cewar wasu masu bincike, wadanda yankuna na DNA da cewa ba encode polypeptides yi kullum ayyuka. The mutum genome iya samun har zuwa dubu 30. Kwayoyin halittu.

kafa na chromosomes

A total number of chromosomes, su siffofin - halayyar alama na da tsari. A gardama Drosophila su lambar - 8, a mannyan birai - 48, da wani mutum - 46. Wannan adadin shi ne akai ga Kwayoyin kwayoyin da cewa ya kasance a cikin wannan jinsin. Domin duk eukaryotes akwai manufar "diploid chromosomes." Wannan cikakken sa, ko 2n, sabanin haploid - rabin adadin (n).

Chromosomes an hada da daya biyu daga homologue wannan siffar, tsari da wuri, centromeres, da kuma sauran abubuwa. Homologues suna da nasu halaye da cewa bambanta su daga sauran chromosomes a cikin sa. Batawa da asali dyes yale mu mu yi la'akari, bincika rarrabe siffofin kowane biyu. Diploid chromosomes ne ba a somatic Kwayoyin haploid guda - a cikin jam (abin da ake kira gametes). A dabbobi masu shayarwa da sauran kwayoyin da ɗa namiji heterogametic kafa iri biyu jima'i chromosomes: X chromosome da Y. maza da wani sa na XY, mãtan - XX.

Human chromosome sa

jikin mutum Kwayoyin dauke da 46 chromosomes. Dukan su suna hade a 23 nau'i-nau'i cewa yin up sa. Akwai iri biyu chromosomes autosomes da kuma jima'i. A farko form 22 nau'i-nau'i - su ne na kowa da mata da kuma maza. Suna halin da 23rd biyu - jima'i chromosomes, wanda suke da sel da namiji jiki ne maras homologue.

Halitta dabiu hade tare da jinsi. Domin watsa ne Y da kuma X chromosome a cikin maza, biyu X mata. Autosomes dauke da sauran bayanai game da hereditary halaye. Akwai dabaru da cewa ba da damar sirranta duk 23 nau'i-nau'i. Su ne da ake iya gani a cikin Figures, a lokacin da fentin a wani takamaiman launi. Shi ne m cewa 22-chromosome a cikin mutum genome - da karami. Its DNA a miƙa yanayin yana da tsawon 1.5 cm, kuma yana da miliyan 48 nau'i-nau'i daga nitrogenous sansanonin. Musamman sunadarai histones daga chromatin yi matsawa, sa'an nan da thread daukan dubu sau kasa sarari a cikin cell tsakiya. A karkashin wani na'urar hange, da histones a Interphase tsakiya kama beads, strung a kan wani tufka da DNA.

kwayoyin cututtuka

Akwai kan dubu uku. Various iri hereditary cututtuka da diyya da kuma disturbances a cikin chromosomes. Wadannan sun hada da Down ciwo. Ga wani yaro da kwayoyin cuta halin da bata lokaci ba, a shafi tunanin mutum da kuma ta jiki ci gaba. A cystic fibrosis akwai kasawa a cikin ayyuka na exocrine gland. Take hakkin take kaiwa zuwa matsaloli tare da sweating, saki da kuma jari na gamsai a cikin jiki. Shi ya sa ya wuya aiki cikin huhu zai iya kai ga numfashi matsaloli da kuma mutuwa.

Take hakkin launi hangen nesa - makanta - rigakafi zuwa wasu sassa na launi bakan. Hemophilia take kaiwa zuwa weakening na jini clotting. Lactose rashin ha} uri ba da damar jikin mutum zuwa nike madara da sukari. A ofisoshin tsarin iyali za a iya samu a predisposition zuwa musamman kwayoyin cuta. A manyan cibiyoyin harkokin likita, da damar su sami dace kimantawa da kuma magani.

Gene far - shugabanci na zamani magani, da elucidation na kwayoyin Sanadin hereditary cututtuka da kuma ta kawar. Tare da sabuwar dabaru a pathological Kwayoyin maimakon damuwa gudanar al'ada genes. A wannan yanayin, da likitocin da ba ya taimaka wa haƙuri da cututtuka, da kuma dalilan da cutar. Gyara ne da za'ayi kawai somatic cell gene far ba tukuna massively amfani dangane da jima'i Kwayoyin.