Everybody seemed quite certain that “aleph” is definitely totally Jewish. However, it seems quite a controversial issue in the Poskim whether a child born from a Jewish mother but a non-Jewish father is actually a Jew.
We pasken ???? ???. The Meforshim dispute whether this means Kosher straight away, or Kosher after Geirus (meaning that he isn’t a mamzer). Tosfos in a few places (See ??????? ??:, ????? ?”?) holds that the child is not Jewish. Rashi in ??????? ?”? seems to take on that the child is not Jewish, as he does in the end of Parshas Emor (See ??? ???? who is ?????.) Maharsha and R’ Akiva Eiger bring contradictions about this. The Nesivos paskened the one needs Geirus Lechumra (See also Teshuvos R’ Yaakov Melisa Siman ??).
R’ Eliezer Gordon, in ?????? ??? ?????? ??’ ? wants to learn that even the ???? ??? ???”? pasken like that.
So it’s not so clear.