Gene, genome, chromosome: definition, tsarin, ayyuka

"Gene", "gene", "chromosome" - kalmomi da suke saba wa kowane schoolchild. Amma ra'ayin wannan batu yana da cikakkiyar bambanci, tun da yake don zurfafawa cikin ilimin fasahar halitta na biochemical da sha'awar fahimtar duk wannan ana buƙata. Kuma, idan akwai a matakin son sani, to nan da nan ya ɓacewa a ƙarƙashin nauyi na gabatar da kayan. Bari muyi ƙoƙari mu fahimci abubuwan da ke tattare da abubuwan da ke tattare da su a cikin kimiyya da nau'i na pola.

Mene ne jinsi?

Hanyoyin halitta shine ƙananan tsari da aikin aiki game da ladabi cikin kwayoyin halitta. A gaskiya ma, ƙananan DNA ne, wanda ya ƙunshi bayani game da wasu amino acid don gina gina jiki ko aikin RNA (wanda za'a hada shi da sinadaran). Harshen ya bayyana wadannan halayen da za a gaji da kuma daukar kwayar cutar ta zuriyarsu a gaba da jerin sassan sassa. A wasu kwayoyin unicellular, akwai canza kwayoyin halitta, wanda ba shi da alaka da haifuwa daga irinsu, an kira shi a kwance.

"A kan kafadu" na kwayoyin halitta babban nauyi ne akan yadda kwayoyin halitta da kwayoyin za su duba da kuma aiki gaba daya. Suna sarrafa rayuwarmu daga zanewa zuwa numfashin ƙarshe.

Shirin farko na kimiyyar gaba a cikin nazarin ƙirarren dan Adam Austrian mai suna Gregor Mendel, wanda a cikin 1866 ya wallafa abubuwan da ya lura game da sakamakon yayin da ya tsallake peas. Abubuwan da ke amfani da shi, ya yi amfani da shi, ya nuna alamun fasalin fasali, kamar launi da siffar peas, da furanni. Wannan mutumin ya tsara dokokin da suka kafa farkon kwayoyin halitta a matsayin kimiyya. Ginin gine-ginen yana faruwa ne domin iyaye suna bai wa yaran rabin rabin chromosomes. Saboda haka, alamu na uba da uba, haɗuwa, suna haifar da sabon hade da halaye na yanzu. Abin farin ciki, akwai wasu zaɓuɓɓuka fiye da rayayyun halittu masu rai a duniyar duniyar, kuma baza a iya samun abu guda biyu ba.

Mendel ya nuna cewa haɗin kai ba ya haɗuwa, amma an canja shi daga iyaye zuwa zuriya a cikin nau'i na rarrabe (raunuka). Wadannan raka'a, wakiltar nau'i-nau'i da nau'i-nau'i (alal misali), sun kasance masu sassaucin ra'ayi kuma an kai su zuwa ga al'ummomi masu zuwa a cikin jigilar maza da mata, kowannensu yana dauke da ɗaya daga kowane nau'i. A 1909, Danan dan Johanan Johansen ya kira wadannan kwayoyin halittar. A shekara ta 1912, wani masanin halitta daga Amurka Morgan ya nuna cewa suna cikin chromosomes.

Tun daga wannan lokacin, shekaru fiye da daya da rabi sun shude, kuma bincike ya ci gaba fiye da yadda Mendel ya yi tunanin. A halin yanzu, masana kimiyya sun zauna a kan ra'ayi cewa bayanai a cikin kwayoyin halitta sun ƙaddamar da girma, ci gaba da kuma ayyuka na kwayoyin halitta. Kuma watakila ma mutuwarsu.

Ƙayyadewa

Tsarin gizon ya ƙunshi ba kawai bayani game da sunadarai ba, amma kuma alamun lokacin da yadda za a karanta shi, da kuma wuraren da ba su da kyau don raba bayanin game da sunadarai daban-daban da kuma dakatar da kira na kwayoyin bayani.

Akwai nau'i biyu na kwayoyin halitta:

1. Tsarin - sun ƙunshi bayani game da tsarin sunadaran ko RNA. Tsarin nucleotides yayi daidai da tsari na amino acid.
2. Kwayoyin aiki suna da alhakin daidaita tsarin dukan sassa na DNA, don synchrony da jerin jerin karatunsa.

A yau, masanan kimiyya zasu iya amsa tambayar: yawancin ginsin da suke cikin chromosome? Amsar za ta mamaye ku: kimanin biliyan uku. Kuma wannan shine kawai a cikin ashirin da uku. Jiki shine ƙananan tsarin tsarin, amma zai iya canza rayuwar mutum.

Kashewa

Canje-canje ko makasudin da aka tsara a cikin jerin nucleotides shigar da sarkar DNA ana kira maye gurbi. Ba zai iya rinjayar tsarin gina jiki ba, amma zai iya kawar da dukiyarsa gaba daya. Don haka, za a sami gida ko sakamakon duniya na wannan canji.

Da kansu, maye gurbi na iya zama abin ƙyama, wato, nuna kansu a cikin cututtuka, ko kuma na mutuwa, ba don ƙyale jiki ya ci gaba zuwa wata ƙasa mai daɗi ba. Amma yawancin canje-canjen ba su san shi ba ga mutum. Saukewa da duplication suna ci gaba ne a cikin DNA, amma bazai tasiri rayuwar rayuwar kowane mutum ba.

Share shi ne asarar wani yanki na chromosome wanda ya ƙunshi wasu bayanai. Wani lokaci wasu canje-canje suna da amfani ga jiki. Sun taimaka masa ya kare kansa daga mummunar tashin hankali, irin su cutar rashin daidaitowa na mutum da kwayoyin annoba.

Kwafi shi ne sau biyu na yankin chromosome, wanda ke nufin cewa jinsin halittar da ya ƙunshi sau biyu. Saboda maimaitawar bayanin, ba shi da saukin kamuwa da kiwo, wanda ke nufin zai iya tara matakan maye gurbi kuma ya canza jiki.

Abubuwan da ke cikin jigon

Kowane mutum yana da wata babbar jigidar halittar DNA. Genes ne raka'a aiki a tsarinsa. Amma ko da irin wannan ƙananan mãkirci suna da nasarorin kansu wanda ke ba da izinin kiyaye zaman lafiyar rayuwar rayuwa:

1. Sashin hankali - ikon jinsin kada ku haɗu.
2. Dama - adana tsari da kaddarorin.
3. Lability - iyawar canzawa ƙarƙashin rinjayar yanayi, daidaita da yanayi mai ban tsoro.
4. Yawancin zantuttuka shine kasancewa a cikin DNA na kwayoyin halitta, wanda, wanda ya hada da irin wannan furotin, yana da tsarin daban.
5. Gaskiya - kasancewar siffofin siffofin guda guda.
6. Musamman shine kalma ɗaya = daya daga cikin kwayoyin da aka kawo ta wurin gado.
7. Pleiotropy shine yawancin nau'in sakamako guda daya.
8. Expressiveness - matsakaicin furci na yanayin, wadda aka tsara ta wannan jigon.
9. Zuwanci - yawan saurin abin da ya faru a cikin wani jigon jini a cikin wani jinsi.
10. Ƙarfafawa - bayyanar babban adadi na kwararru a cikin DNA.

Kyakkyawan

Halittar mutum shine duk kayan da ke cikin kwayar halitta daya. Ya ƙunshi umarnin akan gina jikin, aikin gabobin, da kuma canji na jiki. Magana na biyu na wannan lokaci yana nuna tsarin tsarin, ba aiki ba. The mutum genome - wani tarin kwayoyin abu cushe a cikin wani haploid sa na chromosomes (23 nau'i-nau'i) da alaka da wani takamaiman irin.

Dalili na genome ne da kwayoyin da na deoxyribonucleic acid suna da kyau da aka sani da DNA. All kwayoyin dauke da akalla iri biyu bayanai: da masu lamba bayani a kan tsarin da kwayoyin ke tsakiya (abin da ake kira RNA) da kuma gina jiki (wannan bayani yana kunshe ne a cikin halittar da), kazalika da umarnin cewa ayyana lokaci da kuma wuri na nuni da wannan bayani a cikin ci gaban da kwayoyin. Jinsunan suna da wani ɓangare na kwayar halitta, amma su ne tushensa. Bayanin da aka rubuta a cikin jinsin shine nau'in koyarwa don samar da sunadarai, ginshiƙan ginin jikinmu.

Duk da haka, domin a cikakken faye hali na genome arancinsu rajista a shi bayanai game da tsarin da sunadarai. Bukatar karin bayanai game da abubuwa da kwayoyin inji, wanda ya dauki wani ɓangare a cikin aikin kwayoyin halitta tsara su magana a matakai daban-daban na ci gaba da kuma a cikin daban-daban rayuwa yanayi.

Amma ko da wannan bai isa ba don cikakkiyar ma'anar genome. Bayan haka, akwai wasu abubuwan da ke tattare da shi don inganta haifar da kanta (sabuntawa), ƙaddaraccen jigilar DNA a tsakiya, da kuma sauran yankunan wanda ba a iya fahimta ba, wasu lokuta ana kiranta "son kai" (wato, zamu bauta wa kansu). Saboda wadannan dalilai, a halin yanzu, idan yazo da kwayar halitta, suna nufin dukkanin jerin DNA da ke cikin chromosomes na kwayar halitta ta wani nau'i na kwayoyin halitta, ciki har da, da gaske, kwayoyin.

Girman da tsarin tsarin kwayar halitta

Yana da mahimmanci don ɗauka cewa jinsin, kwayar halitta, da chromosome sun bambanta a wasu wakilan rayuwa a duniya. Suna iya kasancewa marasa ƙaranci kuma suna da yawa kuma sun ƙunshi biliyoyin nau'i-nau'i na kwayoyin halitta. Tsarin ginin zai dogara ne akan wanda kake bincike.

Da rashi tsakanin girman girman kwayar halitta da yawan kwayoyin da suka shiga cikin shi, ana iya rarraba nau'i biyu:

1. Karamin kwayoyin halitta wanda ba su da fiye da asusun miliyon goma. A gare su saitin jinsin ya danganta da girman. Mafi halayyar ga ƙwayoyin cuta da prokaryotes.
2. Abubuwa masu yawa sun kunshi nau'i-nau'i fiye da miliyan 100 waɗanda ba su da dangantaka tsakanin tsayininsu da yawan kwayoyin halitta. Ƙari mafi yawa a cikin eukaryotes. Yawancin jerin tsararru a cikin wannan aji ba su ƙone sunadarai ko RNA ba.

Nazarin ya nuna cewa akwai kimanin kwayoyin halitta 28,000 a jikin mutum. Ana rarraba su a fili a fadin chromosomes, amma muhimmancin wannan yanayin ya kasance abin ban mamaki ga masana kimiyya.

Chromosomes

Chromosomes hanya ce ta kunshe da kwayoyin halitta. Sun kasance a cikin tsakiya na kowace ƙwayar eukaryotic kuma yana dauke da kwayar halittar DNA mai tsawo. Za a iya ganin su a cikin wani abu mai zurfi a cikin rabuwa. Karyotype wani tsari ne na chromosomes, wanda ya kebantacce ga kowane jinsin mutum. Muhimman abubuwa masu amfani da su shine batutuwa, maɓallin telomeres da mahimman bayanai.

Canje-canje a cikin chromosomes a cikin tsarin sashin jiki

Gene, genome, chromosome - a serial watsa bayanai kewaye raka'a, inda kowane hada da wadannan gabata. Amma kuma suna fuskantar wasu canje-canje a cikin rayuwar salula. Saboda haka, alal misali, a cikin interphase (lokacin tsakanin rarrabuwa) chromosomes a cikin tsakiya suna da wuri marasa kyau, suna ɗaukar sararin samaniya.

Lokacin da tantanin halitta yayi shiri don mitosis (wato, zuwa tsari na rarraba a biyu), an kwatanta chromatin kuma ya juya zuwa cikin chromosomes, kuma a yanzu an bayyane shi a microscope mai haske. A misali, chromosomes suna kama da sandunansu da ke kusa da juna kuma suna haɗuwa ta hanyar ƙaddamarwa ta farko, ko ta hanyar ɗita. Ita ne wanda ke da alhakin samuwar rabuwa, lokacin da ƙungiyoyin chromosomes suka tashi. Dangane da wurin da aka samu a tsakiya, akwai irin wannan tsari na chromosomes:

1. Aiki - a cikin wannan yanayin an samo centromer ne a cikin tsaka-tsaki game da tsakiyar chromosome.
2. Tsakanin ƙasa, lokacin da kafadu (wato, yankunan kafin da bayan bayanan) ba su da tsayi.
3. Menecentric, idan centromer ya raba chromosome daidai a tsakiya.

An tsara wannan jinsin chromosomes a cikin 1912 kuma masu amfani da ilimin halitta sunyi amfani har zuwa yau.

Anomalies na chromosomes

Kamar yadda sauran kwayoyin halittu na kwayoyin halitta suke ciki, chromosomes na iya shawo kan canje-canjen tsarin da zasu shafi ayyukan su:

1. Ra'ayi. Wannan canji a yawan adadin chromosomes a cikin karyotype ta ƙara ko cire daya daga cikinsu. Sakamakon irin wannan maye gurbi na iya zama na mutuwa ga jaririn da ba a taɓa ciki, da kuma haifar da lahani ba.
2. Polyploidy. Ya bayyana a matsayin karuwa a yawan adadin chromosomes, adadi na rabi na lambar. An samo shi da yawa a tsire-tsire, irin su algae, da fungi.
3. Chromosomal aberrations, ko sake fasalin kudin, - wani canji a cikin tsarin da chromosome a ƙarƙashin rinjayar muhalli dalilai.

Genetics

Genetics kimiyya ne da ke nazarin ka'idojin rashin daidaituwa da kuma canji, kuma yana ba da hanyoyin samar da halittu. Ba kamar sauran kimiyyar ilimin halitta ba, tun daga lokacin da aka samo shi ya nema kimiyya daidai. Dukan tarihin jinsin halitta shine tarihin halittar da amfani da hanyoyin da kuma hanyoyin da suka dace. Dabaru da hanyoyi na jinsin suna taka muhimmiyar rawa a magani, noma, aikin injiniya, masana'antun kwayoyin halitta.

Gadar hali - jiki ta ikon samar a cikin jerin intergenerational ci gaba da morphological, biochemical kuma physiological halaye da kuma siffofin. A cikin gado, babban nau'i-nau'i, ƙungiya (kabilanci, yawan jama'a) da siffofin iyali na tsari da aiki da kwayoyin halitta, haɓakar juna (ci gaban mutum) ana haifar da su. Gida ba kawai wasu siffofi da ayyuka na jiki ba (siffofin fuskar jiki, wasu siffofi na matakai na rayuwa, yanayin, da dai sauransu), amma har da siffofin tsarin jiki na tsarin tsarin da kuma aiki da magunguna na kwayar halitta. Bambanci shine bambancin halaye tsakanin wakilan wata jinsin, da kuma dukiyar dangi don samun bambance-bambance daga siffofin iyaye. Bambanci, tare da ladabi, sune nau'i biyu na kwayoyin halitta.

Down Ciwo

Ciwo na ciwo shine cututtukan kwayoyin halitta inda karyotype ya ƙunshi 47 chromosomes a cikin mutane maimakon saba 46. Wannan yana daya daga cikin siffofin sabon abu, wanda aka ambata a sama. A cikin kashi ashirin da biyu na chromosomes, wani ƙarin ya bayyana, wanda ya gabatar da ƙarin bayanan kwayoyin cikin jikin mutum.

Sunan ciwonsa shine don girmama likitancin, Don Down, wanda ya gano shi kuma ya bayyana shi a cikin litattafai a matsayin wani nau'i na rashin tunani a cikin shekara ta 1866. Amma an gano tushen bayanan kusan kusan shekaru ɗari daga baya.

Epidemiology

A halin yanzu, karyotype a cikin 47 chromosomes a cikin mutane yana faruwa sau ɗaya a kowace shekara (fiye da jariri). Wannan ya yiwu saboda samin asali na wannan pathology. Kwayar ba ta dogara ne akan tseren, kabilanci na mahaifi ko matsayin zamantakewa ba. Yau shekaru. Matsalar ciwon jariri tare da Down ta ciwo ya karu bayan shekaru talatin da biyar, kuma bayan shekaru arbain raunin yara masu lafiya ga marasa lafiya 20 zuwa 1. Shekaru na mahaifinsa a cikin shekaru arba'in kuma yana ƙara yawan damar samun yarinya tare da sakewa.

Hanyoyin Down Down

Abinda ya fi dacewa shi ne bayyanar da wani samfurin chromosome a cikin kashi ashirin da biyu da biyu tare da hanyar da ba a raba shi ba. Yana da saboda gaskiyar cewa a wannan lokacin wannan nau'in ba ya rabuwa ta hanyar fission spindle. A kashi biyar cikin dari na lokuta, akwai mosaicism (ƙarin chromosome ba a cikin dukkan kwayoyin jiki ba). Tare da su suna da kashi 54 cikin dari na yawan mutanen da ke da wannan yanayin. A cikin kashi biyar cikin dari na lokuta, cutar ta haifar da ciwon haɗin gwargwadon ƙwayar cuta ashirin da ɗaya. Duk da haka, haihuwar yara biyu da wannan cuta a cikin iyali daya ba shi da muhimmanci.

Clinic

Mutumin da ke fama da ciwon Down zai iya gane shi ta hanyar halayen halayen halayen su, ga wasu daga cikinsu:

- fuskar fuska;
- kwanyar da aka raguwa (girman giciye mai girma fiye da na tsaye);
- fatar jiki a wuyansa;
- ninka fata da ke rufe ɗakin ido na ciki;
- matsanancin motsi na gidajen abinci;
- rage ƙwayar tsoka;
- ladabi na occiput;
- gajeren yatsun da yatsunsu;
- ci gaban cataract a cikin yara ya fi na shekaru takwas;
- ƙwayoyin cuta a ci gaba da hakora da kuma tauraron dan adam;
- cututtukan cututtukan zuciya;
- yiwuwar ciwo mai cututtuka mai yiwuwa ne;
- cutar sankarar bargo.

Amma ba zato ba tsammani don tantancewa, wanda yake dogara ne kawai a kan nuni waje, hakika, ba zai yiwu ba. Dole ne a aiwatar da karyotyping.

Kammalawa

Gene, gene, chromosome - ga alama cewa yana da kawai wata kalma wadda ma'anar da muka fahimta tare da sosai mugun. Amma a gaskiya, suka karfi da shafi rayuwarmu da kuma juyin juya hali, da kuma muna tilasta canza. Mutumin ya san yadda za a daidaita da yanayi, da abin da suka kasance, da kuma ko ga mutane da kwayoyin munanan akwai ko da yaushe wani lokaci da kuma wuri inda za su zama irreplaceable.