Kodi khromozomu? Ikani DNA. A peyala ya DNA

Chibadwa ndi masiyanidwe mu chikhalidwe kulibe chifukwa DNA, majini, deoxyribonucleic acid (DNA). Masitolo ndi transmits uthengawu ku maselo mawonekedwe a maunyolo nucleotides mu DNA. Kodi mbali chodabwitsa izi ndi za chibadwa? ndi khromozomu mawu a kufala kwa makhalidwe cholowa chiyani? Mayankho a mafunso amenewa kumvetsa mfundo ya 'kala' ikusonyeza ndi kuchuluka majini padziko lathuli. Pamlingo waukulu zimadalira m'mene khromozomu kwambiri akulowa anapereka, ku recombination nyumba izi.

Mbiri ya kutsegula kwa "chibadwa tinthu"

Kuphunzira pansi maso ndi maselo a zomera ndi nyama, botanists ambiri ndi maphunziro akadali cha m'ma XIX, anafotokoza ulusi abwino ndi laling'ono annular dongosolo mu phata la. zambiri kuposa DNA ena otchedwa mpainiya wa German anatomist WALTHER Flemming. Kuti ntchito aniline utoto kwa processing wa nyumba nyukiliya. Fleming anatulukira mankhwala otchedwa "chromatin" kwa luso lake kudetsa. Mawu akuti "khromozomu" mu 1888 kukhazikitsa ulimi wa sayansi Genrih Valdeyer.

Pa nthawi yomweyo Flemming anali kufunafuna yankho la funso la chimene khromozomu, ndi Belgium Edouard Van Beneden. A pang'ono m'mbuyomo German zamoyo Theodor Boveri ndi Eduard Strasburger anachita mndandanda wa zinthu zatsopano kutsimikizira chizindikiro DNA, ndi zonse za chiwerengero chawo mu mitundu yosiyanasiyana ya zamoyo.

ANAKULIRA chromosomal chiphunzitso cha chibadwa

American katswiri Walter Sutton tinapeza DNA angati opezeka phata selo. Scientific anakhulupirira nyumba izi onyamula mayunitsi cha chibadwa, makhalidwe thupi. Sutton anapeza kuti DNA zigwirizana majini, kudzera amene wadutsa kuchokera ku makolo ndi ana katundu ndi ntchito. Zachibadwa m'mabuku anafotokoza khromozomu awiriawiri, kayendedwe kawo pa gulu la phata selo.

Kaya anzake a American, ntchito mbali imodzi anatsogolera Theodor Boveri. Onse ofufuza ntchito kuphunzira nkhani ya kusintha kwa makhalidwe cholowa, kukonza chakudya zofunika pa ntchito ya DNA (1902-1903). pofuna kukwaniritsa chiphunzitso Boveri-Sutton zinachitika mu zasayansi ya Nobel Thomas Morgan. Wopambana American zamoyo ndi gulu lake akhazikitsa mndandanda wa malamulo a kuwayika chibadwa pa khromozomu, ife apanga maziko cytological kwa kufotokoza limagwirira a malamulo a Gregor Mendel - bambo kukhazikitsidwa kwa chibadwa.

The DNA selo

Investigation ya kapangidwe ka DNA anayamba Atapeza ndi kufotokoza za m'ma XIX. Izi corpuscles ndipo filaments zili zamoyo prokaryotic (sanali nyukiliya) ndi maselo eukaryotic (mu phata la). Kuphunzira pansi maso kwasonyeza kuti asakhale ndi vutoli ndi mfundo morphological maganizo. Izi mafoni filamentous thupi, lomwe ndi kuonekera mu magawo ena a mkombero selo. Buku lonse la interphase phata chromatin ali. Mu nthawi zina distinguishable khromozomu mu chromatids imodzi kapena ziwiri.

Bwino anawona formations zimenezi pa magawano selo - mitosis kapena meiosis. Maselo eukaryotic zambiri kusunga DNA lalikulu dongosolo liniya. Mu prokaryotes, iwo ali ang'onoang'ono, ngakhale pali kuchotserapo. Maselo zambiri monga mtundu kuposa wina DNA Mwachitsanzo ang'ono awo "particles cholowa" ali mitochondria ndi chloroplasts.

mawonekedwe DNA

Aliyense khromozomu ali ndi dongosolo la munthu, wosiyana makhalidwe ena kudetsa. Mu kuphunzira kafukufuku wakapangidwe kazachilengedwe Nkofunika kudziwa udindo wa centromere ndi kutalika ndi mayikidwe a mikono wachibale m'chiuno. Achikhalire DNA nthawi wapangidwa ndi njira zotsatirazi:

• metacentric kapena ofanana, yodziwika ndi malo pakati pa centromere ya;
• submetacentric kapena neravnoplechie (constriction ndi kuchepetsa kwa mmodzi wa telomers);
• acrocentric, kapena ndodo woboola pakati, imene centromere ndi ili pafupifupi kumapeto DNA;
• wa akulozera ndi mawonekedwe nkomwe definable.

khromozomu ntchito

DNA ndi lopangidwa ndi chibadwa - ndi mayunitsi zinchito cha chibadwa. Telomeres - malekezero a mikono khromozomu. zinthu izi apadera kutumikira kwa chitetezo zidutswa kuwonongeka, antiblock. Centromere amagwiranso ntchito yake ndi anawaonjezera kuwirikiza kawiri DNA lapansi. Iwo ali kinetochore, iye wokwera dongosolo spindle. Mugulu DNA ndi munthu pa malo malo centromere lapansi. Filaments ntchito spindle kuti maselo mwana chimafika pa khromozomu wina, koma osati onse. Yunifolomu anawaonjezera kuwirikiza kawiri mu ndondomeko fission amapereka chiyambi cha tizilombo ta. Mwendo wina asakhale ndi vutoli limayamba imodzi pa malo osiyanasiyana ngati kuti ndinasintha Iyamba dongosolo lonse kugawa.

Ntchito ya DNA ndi RNA

Kupeza zimene munthu asakhale ndi vutoli, amene ndi ntchito ya nyumba imeneyi nyukiliya analephera kuphunzira kapangidwe kake amuzolengedwa ndi katundu. Maselo eukaryotic, DNA nyukiliya anapanga ndi chuma zinaphatikizidwa - chromatin. Malinga ndi kuwunika, tichipeza zinthu mkulu maselo kulemera organic:

• deoxyribonucleic acid (DNA);
• asidi ribonucleic (RNA);
• histone mapuloteni.

zidulo mkati akutenga mbali mwachindunji biosynthesis la amino zidulo ndi mapulotini kupereka kufala kwa makhalidwe cholowa ku mibadwomibadwo. DNA ali phata la maselo eukaryotic, RNA ndi anaikira mu cytoplasm lapansi.

majini

X-ray kusanthula anasonyeza kuti DNA ndipamene mwauzimu pawiri, zomwe zigwirizana ndi unyolo wa nucleotides. Iwo kuimira zimam'patsa deoxyribose, mankwala gulu ndi mmodzi wa zapansi anayi nitrogenous:

1. A - adenine.
2. G - guanine.
3. T - thymine.
4. C - cytosine.

Zambiri dezoksiribonukleoproteidnyh helical filaments - ndi chibadwa onyamula mudziwe yosiyanasiyana za ndondomeko ya amino zidulo mu mapuloteni kapena RNA. Pa chulutsa makhalidwe cholowa kwa makolo ana imafalikira mu mawonekedwe a alleles mbewu. Amasankha kugwira ntchito, kukula ndi chitukuko cha makamaka chamoyo. Ofufuza ena, anthu m'madera a DNA kuti musakhale encode polypeptides ntchito zolimbana. Matupi a anthu akhoza kukhala Chibadwa 30 chikwi..

anapereka DNA

Chiwerengero cha DNA, zizindikiro zawo - Mbali khalidwe la mawonekedwe. Mu ntchentche Drosophila chiwerengero chawo - 8, mu anyani - 48, munthu - 46. nambala imeneyi nthawi zonse kwa maselo a zamoyo za mtundu womwewo. Pakuti eukaryotes onse pali lingaliro la "DNA diploid." Izi amaika zonse, kapena 2n, mosiyana haploid - theka kuchuluka (n).

DNA ndi lopangidwa ndi peyala imodzi ya magazi mawonekedwe omwewo, kapangidwe, malo, centromeres, ndi zinthu zina. Homologues ndi makhalidwe awo kuti kusiyanitsa iwo kuchokera DNA ena Anatipatsa. Kudetsa ndi utoto zofunika amatilola kuganizira, kufufuza zinthu zapadera lirilonse. DNA Diploid chili mwa somatic maselo haploid yomweyo - mu nyongolosi (otchedwa gametes). Mu nyama ndi zinthu zina ndi heterogametic chiwalo chachimuna anapanga mitundu iwiri ya DNA kugonana: X khromozomu ndi Y. Aamuna ndi ya XY, akazi - XX.

Anthu asakhale ndi vutoli akonzedwa

anthu maselo a thupi ali 46 DNA. Onsewo amaphatikizidwa awiriawiri 23 amene amapanga akonzedwa. Pali mitundu iwiri ya DNA autosomes ndi kugonana. Woyamba mawonekedwe 22 awiriawiri - sizachilendo kwa akazi ndi amuna. Iwo yodziwika ndi aŵiri 23 - kugonana DNA, amene maselo a thupi mwamuna si a magazi.

makhalidwe majini kugwirizana ndi jenda. Pakuti HIV ndi Y ndi X khromozomu amuna awiri X akazi. Autosomes muli zina zokhudza makhalidwe cholowa. Pali njira kuti kulola Makonda awiriawiri onse 23. Iwo ali bwino kuonekera kanjedza, pamene utoto mumtundu yeniyeni. Ndi noticeable kuti 22 khromozomu mu matupi a anthu - laling'ono. DNA ake mu chikhalidwe anatambasula ali ndi kutalika kwa 1.5 cm, ndipo ali awiriawiri miliyoni 48 zapansi nitrogenous. Special mapuloteni histones ku chromatin amagwira psinjika, ndiyeno ulusi amatenga malo zikwi zochepa mu phata selo. Pansi ndi elekitironi maso, ndi histones mu phata interphase amafanana mikanda, kuziluka pa chingwe cha DNA.

matenda majini

Pali zikwi zitatu. Zosiyanasiyanazo matenda otengera chifukwa cha kumawononga ndi chisokonezo DNA lapansi. Zikuphatikizapo ozerezeka. Mwana ndi matenda majini yodziwika ndi Kuchedwa kukula m'maganizo ndi m'thupi. Mu enaake fibrosis pali kulephereka ntchito za zopangitsa exocrine. Violation kumayambitsa mavuto ndi thukuta, kumasuka ndi kudzikundikira ntchofu mu thupi. Izo zimapangitsa izo zovuta ntchito mapapo zingachititse mavuto kupuma ndi imfa.

Kulakwila masomphenya mtundu - khungu - asanazolowere mbali zina za mtundu sipekitiramu. Amapatsira mwana wake kumabweretsa kufooka kwa clotting magazi. Lactose tsankho salola thupi kudya shuga mkaka. M'mautumiki za kulera angapezeke pa kutengera za matenda makamaka chibadwa. Mu malo akuluakulu ambiri a zachipatala ndi mwayi wolandira kuwunika yoyenera ndiponso chithandizo.

Gene mankhwala - malangizo a mankhwala ano, elucidation zomwe zimayambitsa chibadwa cha matenda otengera ndi kuwonongedwa kwake. Ndi maluso atsopano mu maselo pathological m'malo kutanganidwa kutumikiridwa majini yachibadwa. Pankhaniyi, madokotala sanali kuthetsa wodwala matendawa ndi zifukwa matendawa. Kudzudzulidwa ikuchitika yekha somatic selo jini mankhwala sanayambebe massively ntchito mwachibale kwa maselo kugonana.