Gamete ilmin halitta - shi ne ... Jigon manufar

Gamete - shi ne jiki ta nazarin halittu jima'i Kwayoyin dauke da guda sa na chromosomes. Gametes taka muhimmiyar rawa a cikin hadi da fetal ci gaba. La'akari da jikin mutum, a kowane somatic (ba haihuwa) cell cewa shi ne 46 chromosomes, cewa shi ne diploid. Kawai a cikin jam sel, gametes, yawan chromosomes ne 23. A lokacin da wadannan Kwayoyin fis, wani zygote aka kafa tare da cikakken sa na chromosomes.

Wannan tsari da za a tattauna a more daki-daki a kasa. A farko bincika daki-daki, abin da yake cikin gamete ilmin halitta. Wannan jam sel zama dole ga haifuwa. Amma abin da yake da tsarin da kuma ilmin jikin mutum? Bari mu yi nazarin wannan tambaya a cikin daki-daki.

gametogenesis

Gametogenesis - gamete maturation aiwatar a cikin jiki. Yana nufin spermatogenesis (a cikin maza) kuma oogenesis (a mace). Gametogenesis ne ba a cikin rayuwa ta sake zagayowar daga kwayar dabbobi da kuma shuke-shuke: algae, fungi, arthropod, da tsuntsaye, halittar dabba mai kafafuwa, mollusks, dabbobi masu shayarwa.

Anatomy of gametes

Mace gamete ilmin halitta - ne kwai. An kafa a sakamakon oogenesis. Dauke da kwai wadata da na gina jiki zama dole domin ci gaba da zygote bayan hadi. Su immobile da muhimmanci (game da 100,000 sau) Excel a size ɗa namiji Kwayoyin.

Male gamete ilmin halitta - a maniyyi. Wadannan Kwayoyin suna da yawa fiye da karami da mace gamete. Suna da flagella cewa yin maniyyi motility da kuma taimakawa wajen gabatarwa na mace jam sel. A arthropod maniyyi da flagella, amma shi ne wajen wani banda ga mulkin.

A hoton da ke ƙasa nuna hotunan namiji da mace gametes - qwai da maniyyi.

A nazarin halittu rawa

Mene ne gamete ilmin halitta? Definition da kuma ayyuka sun riga sun bayyana, za mu magance su nazarin halittu rawa. Gametes taka muhimmiyar rawa a haifuwa. Tattara abubuwa masu kyau, namiji da mace gamete samar da wata zygote - keji da cikakken diploid chromosomes. The mutum kwai daya ne kawai irin chromosome - X. Tun maza da kuma X- da Y-chromosome maniyyi wani bangare ne X, kuma wani ɓangare - Y chromosome. Dangane da abin da irin maniyyi da takin wani kwai dogara a kan jima'i da yaro. XX chromosomes encode mace, XY - namiji.

Nan da nan bayan hadi, zygote fara girma da kuma raba. Tu da wani kwan da ya hadu ne a stock na gina jiki a cikin nau'i na kwai gwaiduwa. Zygote ne a lokacin da ya zama a cikin wani m jihar, ba raba da ba ci gaba kafin farko na sharadi gwargwado. Wannan irin ci gaba ne halayyar wasu shuke-shuke.

By yawan kwai gina jiki kasu kashi aletsitalnye (ba tare da gwaiduwa) oligoletsitalnye (da kananan adadin gina jiki), mezoletsitalnye (talakawan yawan gina jiki), poliletsitalnye (tare da manyan yawan gwaiduwa). Yana iya ƙarasa da cewa gamete ilmin halitta - a jima'i cell, ba tare da wanda haifuwa tsakanin mutane da aka ba jinsunan.