Bekhorot 42: Different in One Way, Different in Another Way

With regard to an animal that is an androgynos, with both male and female sexual organs, is not considered for a first-born status, because it's not uniquely male. With editorial comments, as it were, made about the baraita that establishes these standards. Also, a tannaitic dispute on a tumtum (human) -- if this person betroths a woman, we accept the kiddushin, because the tumtum might be male. And if a man betroths a tumtum -- also, we accept the kiddushin, because the person might be female. What if the tumtum is male, but also sterile? One who is sterile has different standing with regard to the marital rules -- in terms of yibum, for example.