Mhedziso ye "kuberekwa kwehupenyu hutsva", sekutonga, inongogumirirwa chete nesangano pamusoro pemubereki wemwana semugumisiro wemusangano unoshuva weii uye chirume. Uyezve, maererano nehuwandu, hucheche hunoitika, fetus inokura uye dumbu guru rinowedzera mumamangwana mune ramangwana. Chii chiripo kuti uve akachenjera, zvinhu zvose zvinotora nyore ... Kutaura zvazviri, kufambira mberi kwevanhu vasati vaberekwa kunonyanya kukosha uye kwakashata, zvinoda zvakadzidza kudzidza. Ngatiedzei kunzwisisa zvinonzwisisika zveimwe yezvikamu zvaro - kupatsanurwa kwe zygote.
Zygote is fertilized sperm ovum. Izvo ndezvekuzadza, izvo zvinogona kuitika mukati memazuva matatu mushure mokurara kwepabonde, intrauterine kukura kwevanhu kunotanga. Somugumisiro wekupindira kwe spermatozoon muzai, nuclei yavo inosanganiswa ne chromosomal seti ye 23 mababa uye ma 23 chromosomes amai uye nucleus inoumbwa neyese ye 46 chromosomes inherent mumasero ese emuviri, kusina masero emagetsi. Mushure meizvi, zygote inopwanyika.
Kuparadzaniswa kwevanhu zygote isitiro yezuva rezuva rekuparadzanisa embryo muzvikamu zviduku zveesero kuburikidza nekudzikisa chimiro chavo nenzira yakangofanana nechimiro chemai amai (mitosis kana kuti fission kuburikidza nemhando yecloning) asi ichichengetedza hukuru hwayo (anenge 130 μm). Blastomers - masero akaumbwa panguva yekuparadzaniswa kwe zygote, uyewo akaparadzanisa, uye pamitemo yakasiyana, mune mamwe mazwi, kupatsanurwa kwavo hakukwanisi.
Somugumisiro weboka rokutanga re zygote, pane maviri akasiyana-siyana blastomeres. Chimwe, chikuru, "rima", ndicho chikonzero chekugadzirwa kwemasukirwo nhengo dzemukati. Izvo zvakagadziriswa zvakakura zvinowanikwa mumakamu akatevera zvinonzi embryoblast. Chechipiri, chiduku uye "chiedza" chine blastomer, kupatsanurwa kwacho kunoitika nokukurumidza, kunogadzirisa zvakangofanana - trophoblast. Nekubatsira kwayo kune minwe-yakafanana villi, inofanirwa kuti kugadziriswa kwekupedzisira kwe zygote kune uterine cavity. Blastomeres, pasina kubatana nemumwe nemumwe, inobatwa nerubatsiro rwegozi rimwe chete rinobwinya reii. Kuputika kwayo kunogona kutungamirira kukurudzirwa kwemazamu akasiyana-siyana, somuenzaniso, mapatya akafanana.
Kuonekwa kwema-multicellular embryo
Somugumisiro wekuparadzana kwezygote, mavara akawanda embryo anoumbwa, anoumbwa nezvikamu zvemasero embryoblast (mukati) uye trophoblast (periphery). Ichi ndicho chikwata che morula - nguva yekukura kweumumiresi, umo mune masero zana muBud, kupwanya uye
Panenge pazuva rechigumi nemapfumbamwe, embryo (implantation) ye embryo inokura mumadziro emuviri, iyo inenge iri mumamiriro ezvinhu akakwana emasero ayo. Kubvira panguva ino mudzimai anodzika kuenda kumwedzi, uye iwe unogona kugona kutanga kwekuita pamuviri.