Mosebetsi oa ho ikatisa le moelelo oa likokoana-hloko oa meiosis

Mosebetsi oa ho ikatisa oa 'mele o etsoa ka mokhoa oa ho kopanya li-gametes tse peli (lisele tsa thobalano) ha morali oa morali, lehe le nang le manyolo, a simoloha' me ka mor'a moo o hlaha ho zygote. Lisele tsa batsoali tsa thobalano li na le li-n-chromosomes tse itseng. E bitsoa haploid. Zygote, ha a amohela lihlopha tsena, e fetoha sele ea diploid, i. E. Palo ea li-chromosome ho na le 2n: ngoe ea bo-'mè le e le 'ngoe. Ntho ea bohlokoa ea tlhaho ea meiosis e le karohano e ikhethang ka lisele ke hore ke ka lebaka la hore sele e haploid e thehoa ho tloha lisele tsa diploid.

Tlhaloso

Bielo ea Meiosis e atisa ho bitsoa mofuta oa mitosis; Ka lebaka la lisele tsa eona tsa diploid somatic tsa liphatsa tsa lefutso li arotsoe ka 1n gametes. Ha nucleus e ntse e lengoa, li-gametes lia fuse. Ka hona, setho sa 2n chromosome se tsosolosoa. Se boleloang ke meiosis ke ho netefatsa hore polokelo ea chromosomal e bolokehile le hore na DNA e lekanang le e 'ngoe le e' ngoe ea lintho tse phelang.

Tlhaloso

Meiosis ke mokhoa o tsoelang pele. E na le mefuta e 'meli ea karohano, e latellanang ka katleho: meiosis I le meiosis II. Mokhoa ona ka mong o na le prophase, metaphase, anaphase, telophase. Sehlopha sa pele sa meiosis, kapa meiosis I, se fokotsa palo ea li-chromosome, e.g. Ho na le mohlolo oa seo ho thoeng ke fission fission. Ha mohato oa bobeli oa meiosis o hlaha, kapa meiosis II, haploidity ea lisele ha e sokele phetoho, e sala. Ts'ebetso ena e bitsoa ho arohana ha leano.

Lisele tsohle tse setsing sa meiosis li na le boitsebiso bo itseng ho liphatsa tsa lefutso.

• Phase ea meiosis ea pele ke sethaleng sa khromatin le ho thehoa ha li-chromosome. Qetellong ea ketso ena e rarahaneng haholo, liphatsa tsa lefutso li teng ka mokhoa oa sona oa pele - li-chromosome tse 2n2.
• Metaphase e fihla - boemo bo phahameng ba spiralization bo boetse bo tla. Liphatsa tsa lefutso ha li fetohe.
• Anaphase meiosis e tsamaisana le ho fokotseha. Lihlopha tse ling tsa li-chromosome tsa motsoali li fana ka e 'ngoe ea li-cell phone tsa eona. Boitsebiso ba liphatsa tsa lefutso bo fapana ka boqapi, hobane Palo ea li-chromosome e fokotsehile habeli: hobane palo e 'ngoe le e' ngoe ea sele e na le li-chromosome tse 1n2.
• The telophase ke mohato, ha nucleus e thehoa, cytoplasm e arohane. Lisele tsa morali lia bōptjoa, ho na le tse peli tsa tsona, le ka li-chromatids tse peli. Eena. Sekheo sa li-chromosome ho tsona ke haploid.
• Joale ho na le li-interkinesis, phefumoloho e nyenyane pakeng tsa mehato ea pele le ea bobeli ea meiosis. Lisele tse peli tsa morali li itokiselitse ho kena karolong ea bobeli ea meiosis, e tsoelang pele ho latela mokhoa o tšoanang le oa mitosis.

Ka hona, se boleloang ke likokoana-hloko tsa meiosis, ke hore karolong ea eona ea bobeli, ka lebaka la mekhoa e rarahaneng, ho na le lisele tsa haploid tse 4 - li-chromosome tse 11. Ha e le 'ngoe, sele e' ngoe ea 'mè ea lesea e fana ka bophelo ho ba bane - e' ngoe le e 'ngoe e na le seteishene sa chromosome ea haploid. Karolong e 'ngoe ea meiosis ea tekanyo ea pele, liphatsa tsa lefutso li khutlisetsoa hape,' me karolong ea bobeli li-chromosome le li-chromatids li fallela lipalo tse sa tšoaneng tsa sele. Tsamaiso ena ke mohloli oa mefuta-futa le mefuta e sa tšoaneng ea intraspecific.

Liphetho

Kahoo, bohlokoa ba likokoana-hloko tsa meiosis bo hlile bo monate. Ntlha ea pele, e lokela ho tsejoa e le setsi se ka sehloohong sa liphatsa tsa lefutso tsa gamete. Meiosis e fana ka phetoho ea tlhaho ea liphatsa tsa lefutso tsa mefuta ea liphoofolo ho tloha ho ntho e 'ngoe ho ea ho e' ngoe, hafeela li hlahisa thobalano . Meiosis e hlahisa mefuta e mengata ea intraspecific, hobane Lisele tsa morali li fapana le batsoali ba tsona feela, empa li fapane le tse ling.

Ho phaella moo, bohlokoa ba likokoana-hloko tsa meiosis ke ho fokotsa palo ea li-chromosome nakong ea ha lisele tsa thobalano li thehoa. Meiosis e tiisa thabo ea bona; Nakong ea manyolo ho zygote, mohopolo oa chromosome oa diploid o tsosolosoa.