Reproductive ọrụ na ndu pụtara meiosis

The omumu ọrụ nke ahụ a rụrụ n'oge njikọ nke abụọ gametes (izizi mkpụrụ ndụ) na ihe omume na ụdi mmepe nke zaigọtụ enyemaka ahu - ịmụpụta egg. Mmekọahụ nne na nna mkpụrụ ndụ a na-set nke n-chromosomes. Ọ na-akpọ haploid. Zaigọtụ na-ewere a set nke ndị a, ọ bụ a diploid cell, ie, chromosome nọmba 2n n'ebe: otu nne nwa na otu ọnụmara. Ndu meiotic nkewa pụrụ iche dị mkpa ka na cell mejupụtara ke eziokwu na ekele ya, na-haploid cell kpụrụ si diploid mkpụrụ ndụ.

definition

Meiosis na usoro ndu a na-akpọ a ụdị mitosis; ruru ya diploid somatic sel nke na Genital glands na-ekewa n'ime 1n gametes. Mgbe kernel na-ịmụpụta, e nwere a anọ na nke gametes. N'ihi ya, ọ na-agbake 2n chromosome set. Meaning nke meiosis bụ iji hụ ichebe pụta ụwa ọ bụla ụdị ndụ ntule chromosomes na kwesịrị ekwesị nke ukwu nke DNA.

nkọwa

Meiosis - usoro bụ na-aga n'ihu. Ọ mejupụtara abụọ iche iche nke nkerisi successively esonụ ọ bụla ọzọ: meiosis m na meiosis II. Onye ọ bụla nke Filiks, n'aka nke ya, mejupụtara prophase, metaphase, anaphase, telophase. The akpa nkewa nke meiosis ma ọ bụ meiosis m, halves ọnụ ọgụgụ nke chromosomes, i.e. e nwere onu nke a na-akpọ Mbelata nkewa. Mgbe ọ bụ nke abụọ ogbo nke meiosis ma ọ bụ meiosis II, haploid mkpụrụ ndụ na-adịghị ize mgbanwe, ọ na-azọpụta. Nke a usoro a na-akpọ equational nkewa.

All mkpụrụ ndụ na ogbo nke meiosis, ebu ụfọdụ ozi na mkpụrụ ndụ ihe nketa larịị.

• Meiotic prophase nke mbụ - ogbo nwayọọ helix chromatin na guzobere chromosomes. Ná ngwụsị nke a nnọọ mgbagwoju edinam mkpụrụ ndụ ihe nketa na ihe onwunwe ugbu a na mbụ ya ụdị - 2n2 chromosomes.
• Metaphase abịa - abịa na kacha larịị nke helix. Mkpụrụ ndụ ihe nketa na ihe onwunwe ka na agbanwebeghị.
• Anaphase nke meiosis na-esonyere a Mbelata. Ọ bụla ụzọ nke ndị nne na nna chromosomes enye onye nke ya nwaanyị mkpụrụ ndụ. Genetic ihe gbanwere na mejupụtara, dị ka chromosome nọmba bụ ọkara na: n'ihi na onye ọ bụla osisi nke cell dị mkpa maka 1n2 chromosome.
• Telophase - adọ mgbe akpụ isi, na iche cytoplasm. Nwa mkpụrụ ndụ na-kere, ha 2 ma ọ bụla n'ime abụọ chromatids. ntụgharị setịpụrụ nke chromosomes na haploid ha.
• Ọzọkwa interkinesis hụrụ, a obere ezumike n'etiti mbụ na nke abụọ ogbo nke meiosis. The abụọ nwa mkpụrụ ndụ ndị dị njikere ịbanye nke abụọ ogbo nke meiosis, nke pụtara site n'otu usoro dị ka nke mitosis.

The ndu pụtara meiosis bụ ya mere na eziokwu na ya nzọụkwụ nke abụọ site mgbagwoju usoro ama kpụrụ haploid mkpụrụ ndụ 4 - 1n1 chromosomes. Ie, onye diploid nne cell na-enye ndụ anọ - ọ bụla haploid chromosome set. Na otu n'ime ndị mbụ meiotic ogo adọ mkpụrụ ndụ ihe nketa na ihe onwunwe recombines, na nzọụkwụ nke abụọ a rụrụ ije nke chromosomes na chromatids dị iche iche okporo osisi nke cell. A mmegharị - isi iyi nke mgbanwe na dị iche iche ihe n'ịgwa nke intraspecific.

pụta

N'ihi ya, ndu pụtara meiosis, n'ezie oké. Mbụ niile, ọ ga-kwuru dị ka isi, isi ogbo nke Jenesis nke gametes. Meiosis dịgidere nyefe nke mkpụrụ ndụ ihe nketa na ozi sitere na otu organism umu ọzọ, ọ bụrụhaala na ha mụta nwa mmekọahụ site. Meiosis enyere intraspecific n'ịgwa eme n'ihi na nwa mkpụrụ ndụ dị iche bụghị nanị nne na nna ma na-iche na.

Ke adianade do, ndu pụtara meiosis mejupụtara n'inye mbenata ọnụ ọgụgụ nke chromosomes na oge mgbe izizi mkpụrụ ndụ na-kpụrụ. Meiosis ana achi achi ha haploid; n'oge nke njikọta spam nke zaigọtụ diploid chromosome Ọdịdị na-weghachiri eweghachi.