Becoming a male.
D000818:Animals; D002417:Cattle; D005333:Fetus / Q000502:physiology; D005611:Freemartinism; D005854:Germ Cells / Q000166:cytology; D006128:Growth; D006801:Humans; D008297:Male; D051381:Rats; D012708:Sertoli Cells / Q000166:cytology; D012732:Sex Determination Analysis; D012733:Sex Differentiation; D013737:Testis / Q000033:anatomy & histology / Q000254:growth & development