Gametogenesis - nayo ... gematogeneza mumatanho nezvimiro pabonde kubereka

Nhasi tinopa iwe kuti kubva chirongwa gametogenesis. In pfupi uye zvakajeka, kuti ndiwo muitiro womunhu utachiona sero kukura. Sezvo wava pachena, nyaya uchanamatira kubereka. Cherechedza kuti secrete dzakawanda kurara kubereka. Pasinei chokwadi ichi, vari vose papfungwa kutora chikamu gametes maviri (mukono nehadzi pabonde masero). Tinopa kuti funga mubvunzo uyu zvizere.

syngenesis

Takatodzidza kutaurwa kuti kurara kubereka rinoitwa kuburikidza kutora chikamu kwevanhu vaviri varume navakadzi akasiyana. Vane mumasero anokosha dzokubereka, izvo vanozivikanwa se gametes anobudiswa mune dzimwe nhengo dzomuviri. Uye chii gametogenesis? uku rokuumba utachiona chaizvo masero, izvo zvinodiwa kuberekana. Unofanirawo kuziva chokwadi kuti nedanho kwemapazi gametes anonzi muchangosangana. Meiosis utachiona mutsetse - Nde padariro utachiona sero kukura. We kuriteerera zvishoma kwapera.

Zvino sarudza chimiro pabonde kubereka:

• isogamy;
• heterogamy;
• ovogamiya.

Zvakakosha kuziva kuti zvisingapindirani zvimwe zviri maumbirwo utachiona masero. Somuenzaniso, apo isogamy vanhurume gametes vari pafoni, mukuwedzera, vane zvakafanana miganhu. Zvinotevera muchimiro chakafanana zvikuru yapfuura mumwe. Musiyano mukuru pakati rechipiri - munhukadzi utachiona masero akakura varume, sezvazvakaita kwete Mobile. Chechitatu mhando zvepabonde kubereka ndiyo inonyanya kufarirwa, sezvo rinowanikwa mune mhuka dzakawanda uye zvinomera. In musimboti ichi, hadzi utachiona masero ndee uye yakakura zvikuru kupfuura murume. In chimiro ichi wokuberekana anonzi munhurume gamete - spermatozoa, kana urume, nehadzi - zai.

The mhando mbiri dzokutanga inowanzowanika mumamiriro zvinenge akadai algae. Sei kubereka mu eukaryotes? Kuburikidza kwemapazi vechirume gametes (mazai uye urume). Somugumisiro, fertilization, zygote uye aumba. Zvakakosha kunzwisisa kuti utachiona masero ane chromosome nhamba iri shoma kaviri pane ari somatic muchitokisi. Izvi zvinotsanangurwa nyore: Kana kuwanda okutodza akanga somatic uye nembeu masero chete, muchizvarwa ose, kuti doubling pakati okutodza. Sei izvi hazvina kuitika? Nokuda meiosis, kureva sero nokupesana.

Zvakanakira pabonde kubereka

Utachiona mutsetse - kukura utachiona masero. Sexual kubereka pasina paumbwe gametes zvisingabviri. Zvakakosha kuziva kuti padariro gametogenesis mune varume nevakadzi zvakafanana zvinhu. Muudzame, isu funga izvi gare gare. Zvino isu iwe kupa zvishoma kuti kukurukura zvipenyu zvinoreva pamusoro maberekero uye kubatsira dzepabonde mhando. The mupfungwa kuberekana vakaisa majini. Muchiitiko chino, apo asexual kubereka chikamu muviri zvachose akagadzirwa zvakafanana mubereki kwayo.

Sexual kubereka rakanakira zvakawanda:

• mubatanidzwa rwaamai uye yemadzibaba majini, kureva, hapana mukana wokuti mhedziso nemagene kopi mubereki;
• volatility, mano chavagari kuchinjira kumamiriro ezvinhu matsva kuti apone kwemarudzi;
• akwanise pfungwa speciation, uye zvichingodaro.

spermatogenesis

Isu kare kuti utachiona mutsetse - chirongwa utachiona sero kukura. Zvino kunyatsotarisisa spermatogenesis, kureva, paumbwe dzisingaoneki. Total rakakamurwa muzvikamu zvina:

• kubereka;
• kukura;
• kuibvisa;
• inotungamirwa.

On kubereka rwakazara, mitotic spermatogonia kamura. Pashure paizvozvo, urume ramangwana kuyambukira padariro kukura, zvino vane zita -spermatotsity. kukura Danho kunoratidzwa kuwedzera utachiona mumasero, yakaitwa kukwanisike nokuwedzera bhuku cytoplasm. kuibvisa danho - mapoka maviri. Spermatocyte, iyo kwapfuura rokupedzisira chikuva pasi nokupesana, nokudaro zvichiumba spermatocytes maviri. Zvadaro, mumwe nomumwe wavo inokamukana zvakare. Total, mumwe spermatocytes wokutanga kurongeka, tinowana spermatids mana. Recent apinda mudariro chechina - paumbwe. Chete pashure mumatanho aya dzisingaoneki sero anotora zvatinosiita fomu kwatiri.

ovogenesis

Ovogenesis - kukura hadzi utachiona masero (oocytes). Below akarongwa uye akatsanangura pavaipfuura kwacho.

• Kubereka. Oogonia kugovera mitosis, zvichiguma kwenhamba utachiona masero kuti ramangwana kunowedzera. Zvakakosha kuziva kuti kubereka Danho weveta mwedzi fetus vasikana wechipiri.
• Growth. Danho iri zvachose akagadzirwa zvakafanana chirongwa kukura kwevarume utachiona masero. The musiyano chete - kukura zai akapfuudza kukura yemberi spermatocytes, akafanirwa kuti kuunganidza wokutanga muviri.
• The wokupedzisira pavaipfuura oogenesis - kuibvisa. It kunoratidzwa maviri anotevedzana vakamurwa meiosis. Apo mumwe spermatogenesis spermatocytes vakaumba dzisingaoneki mana. Mune imwe nyaya oogenesis oocyte ovum anokwanisa nokuumba miviri ane vatatu uye polar.

Sei dzisingaoneki vane pauwandu, asi ivo vari vakaderera kukura zai? Dzisingaoneki hazvirevi -wedzera zvinovaka muviri, sezvo kwayo upenyu kutenderera iwayo pfupi. The chikuru kushanda hono nemasero embeu - hurukuro masero zvinhu kupinda zai. Uyezve, tinofanira kuva Mobile chaizvo. Dzisingaoneki vari uchitsvaka zai vakawanda achifa, rinotsanangura zvavo nhamba zvinobatsira.