Canzawa a ilmin halitta - shi ... canzawa Iri

Canzawa a ilmin halitta - shi ne zargin mutum da bambance-bambance tsakanin mutane da wannan nau'in. Saboda da canzawa na yawan zama da iri-irin, da kuma nau'in mafi damar daidaita canza muhalli da yanayi.

A wannan kimiyya, kamar ilmin halitta, gadar hali da kuma bambancin je hannu da hannu. Akwai iri biyu na canzawa:

• Nonhereditary (canji, phenotypic).
• Hereditary (maye gurbi, genotype).

ba-hereditary canzawa

Gyara canzawa a ilmin halitta - da ikon da guda kwayoyin halittar (phenotype) daidaita da wa muhalli dalilai a cikin ta genotype. Saboda wannan dukiya da mutum ya daidaita da canjin yanayi da kuma sauran yanayin zama. Phenotypic bambancin shi ne tushen karbuwa matakai abin da ke faruwa a kowane kwayoyin. Saboda haka, a outbred dabbobi ta inganta da yanayin qara yawan aiki: madara samarwa, kwai samarwa, da sauransu. Da dabbobi, shigo cikin dutsen yankunan, girma tsumburai kuma tare da wani da suka ci gaba undercoat. Canza muhalli dalilai da hanyar canzawa. Misalai na wannan tsari za a iya sauƙi samu a rayuwar yau da kullum: a 'yan Adam fata ne fallasa riskar hasken ultraviolet zama duhu, a sakamakon jiki exertion tsokoki ci gaba, shuke-shuke girma a shaded yankunan da a kan haske, suna daban-daban siffofi na ganye da kuma hares canza launi ulu a hunturu da kuma bazara.

Ga wadanda ba hereditary canzawa ne halin da wadannan Properties:

• kungiyar hali canje-canje.
• An ba da gaji ta zuriyata.
• ãyõyin canji a cikin genotype.
• rabo kudi na canji da tsanani da wani waje factor.

kwayoyin bambancin

Hereditary ko genotypic canzawa a Biology - ne tsari da wanda kwayoyin genome dabam. Godiya ta mutum yakan mallaki halaye baya uncharacteristic na mata zuciya. Kamar yadda Darwin, genotypic canzawa ne babban engine juyin halitta. Wadannan iri kayyade bambancin:

• maye gurbi,
• combinative.

Combinative canzawa faruwa a sakamakon gene musayar ta jima'i haifuwa. A lokaci guda a cikin ãyõyin da iyaye daban hade a wata yawan al'ummomi, kara bambancin da kwayoyin a cikin wata alƙarya. Combinative canzawa bi dokoki na gado Mendel. Wani misali na wannan canzawa - inbreeding da outbreeding (hankali da alaka da alaqa hybridization). Lokacin da siffofin da mutum m so da dorewar irin dabbobi, da amfanin inbreeding. Saboda haka, zuriyarsa zama mafi uniform inganci da gyaran gaba daya da kafa Lines. Inbreeding take kaiwa zuwa magana na recessive genes kuma iya haifar da degeneration na line. Don inganta viability na zuriya amfani outbreeding - outbreeding. A wannan zuriyarsa heterozygosity ƙaruwa kuma qara bambancin cikin yawan jama'a, da kuma yadda wani sakamako, qara kwanciyar hankali ga mutane da zuwa illa muhalli dalilai.

Maye gurbi, bi da bi, ya kasu kashi:

• genome.
• chromosome.
• gene.
• cytoplasmic.

Canje-canje da shafi cikin sel haihuwar, an gaji. Maye gurbi a somatic Kwayoyin za a iya daukar kwayar cutar zuwa zuriya, idan mutum yana vegetatively karbe (shuke-shuke, fungi). Maye gurbi na iya zama da amfani, tsaka tsaki ko cutarwa.

ilimin kwayoyin hali maye gurbi

Canzawa a ilmin halitta da ilimin kwayoyin hali maye gurbi iya zama na biyu iri:

• Polyploidy - maye gurbi fiye samu a tsire-tsire. An sa ta magnification na jimlar yawan chromosomes a tsakiya, kafa a lokacin da take hakkin su da bambance-bambance a cikin cell sandunan a lokacin fission. Polyploid hybrids suna yadu amfani da noma - a shuka hada da fiye da 500 polyploids (albasa, buckwheat, sugar gwoza, radishes, Mint, inabi, da dai sauransu).
• Aneuploidy - karuwa ko raguwa a yawan chromosomes na mutum ma'aurata. Wannan irin maye gurbi ne halin da low fahimcin muhimmancin da mutum. A tartsatsi maye gurbi a cikin mutane - daya karin chromosome a kan 21st biyu Yanã Down ta ciwo.

chromosomal maye gurbi

Canzawa a ilmin halitta da chromosomal maye gurbi bayyana lokacin da canza tsarin chromosomes kansu: asarar karshen rabo, da maimaitawa na wani sa na genes kunna raba gutsure, ɗauke da chromosome kashi zuwa wani wuri, ko kuma don wani chromosome. Irin maye gurbi sukan sa da radiation da kuma sinadaran gurbatawa.

gene maye gurbi

Mafi yawan wadannan maye gurbi bayyana azahiri, kamar yadda yake a recessive hali. Lalacewa ta hanyar gene maye gurbi canza nucleotide jerin - mutum genes - da kuma haifar da bayyanar sunadarai na gina jiki da labari Properties. Gene maye gurbi a cikin mutane sa bayyanuwar wasu hereditary cututtuka - sickle cell anemia, hemophilia.

cytoplasmic maye gurbi

Cytoplasmic maye gurbi suna hade da canje-canje a cikin Tsarin daga cikin cell cytoplasm dauke da wani jigidar halittar DNA. Yana mitochondria da plastids. Irin maye gurbi ake daukar kwayar cutar ta hanyar da masu juna biyu line, a matsayin zygote samun duk masu juna biyu cytoplasm na kwai. Misali cytoplasmic maye gurbi sa ta canzawa a ilmin halitta - shi peristolistnost shuka, wanda aka sa ta canje-canje a cikin chloroplast.

Domin duk maye gurbi ne halin da wadannan Properties:

• Sun bayyana ba zato ba tsammani.
• Gaji.
• Ba su da wani shugabanci. Maye gurbi iya fallasa a matsayin qananan rabo da kuma m alamu.
• Tashi, a daidaikun mutane, cewa shi ne na musamman.
• A ta bayyana maye gurbi iya zama rinjaye ko recessive.
• A wannan maye gurbi za a iya maimaita.

Kowane maye gurbi ne ya sa ta wasu dalilai. A mafi yawan lokuta, don a san da shi ya gaza. A gwaji yanayin amfani da su samu maye gurbi na factor directed zuwa waje yanayi - da radiation daukan hotuna da kuma kama.