Nhng Vn V Kinh Nguyt Ph N

Nguyn nhn g v vo lc no th gii tnh ca con ngi c quyt nh? tr li cu hi ny, cc nh khoa hc tin hnh nghin cu trong nhiu nm v khng nh c rng: Gii tnh ca con ngi c quyt nh bi nhim sc th mang cc t bo sinh dc ca cha m. l nhng thng tin v di truyn c cha ng trong nhn t bo ca trng v tinh trng.Trong thi k u phi thai, gii tnh ca con ngi cha c phn nh r rng. Nu phi thai ny l do tinh trng mang nhim sc th Y ca ngi cha v trng ca ngi m (mang nhim sc th X) kt hp m thnh, tuyn sinh dc nguyn thy ca n s dn dn pht trin thnh tinh hon. Phi thai ny s pht trin thnh mt c th nam gii. Ngc li, nu phi thai l do tinh trng mang nhim sc th X v trng kt hp vi nhau, tuyn sinh dc nguyn thy s dn dn pht trin thnh bung trng v mt c th n s hnh thnh. Qu trnh phn ha tuyn sinh dc nguyn thy s bt u vo khong tun th 6-7 ca phi thai v s hon thnh khi phi thai c 18-25 tun.Ngoi s khc nhau v nhim sc th v tuyn sinh dc, gia nam v n cn c s khc bit v kt cu cc c quan sinh dc trong v ngoi, cc loi hoc mn trong c th. giai on u, trong mi phi thai u c hai h thng ng dn gi l h ng dn trung thn v h ng dn trung thn ph. Lc ny phi thai cha c s khc bit v gii tnh.Tinh hon ca ca thai nhi nam c th to ra testosteron v mt loi protein c kh nng c ch h ng dn trung thn ph. Di s kch thch ca testosteron, h ng dn trung thn dn dn pht trin thnh cc c quan sinh dc trong nh ng dn tinh v bao tinh hon. Cn di tc dng c ch ca loi protein ni trn, h ng dn trung thn ph dn dn thoi ha. Sau , testosteron s chuyn bin thnh mt loi hoc mn khc c quan sinh dc ngoi pht trin thnh m nang, dng vt v tuyn tin lit.Trong c th thai nhi n, do khng c protein c ch nn ng dn trung thn ph s t bin i thnh hai ng dn trng, t cung v on trn m o. Do khng chu nh hng ca testosteron nn ng dn trung thn t ng thoi ha. C quan sinh dc ngoi pht trin thnh dng n gii, tc l c mi ln, mi b, m vt v on di m o.S phn ha c quan sinh dc trong cng c hon thnh trc tun th 16-23 ca thai nhi.
PriceUSD0
LicenseFree
File Size2.52 MB
Version1.0
Operating System iOS
System RequirementsCompatible with: iphone3gs, iphone3gs, ipadwifi, ipadwifi, ipad3g, ipad3g, ipodtouchthirdgen, ipodtouchthirdgen, iphone4, iphone4, ipodtouchfourthgen, ipodtouchfourthgen, ipad2wifi, ipad2wifi, ipad23g, ipad23g, iphone4s, iphone4s, ipadthirdgen, ipadthirdgen, ipadthirdgen4g, ipadthirdgen4g, iphone5, iphone5, ipodtouchfifthgen, ipodtouchfifthgen, ipadfourthgen, ipadfourthgen, ipadfourthgen4g, ipadfourthgen4g, ipadmini, ipadmini, ipadmini4g, ipadmini4g