cantante = singer (masc. or fem.) - el cantante, la cantante
bailarín = dancer (masc.) - el bailarín
atleta = athelete (masc. or fem.) - el atleta, la atleta
joven = young / young person (masc. or fem.) - el joven, la joven
B. Bailarín can refer to a boy, but not a girl, because the feminine is bailarina. All the others can refer to both boy or girl.