Well, I heard that a Jew only has to keep a Noahide law if it's repeated in the Torah, since Jews aren't obligated in Noahide laws. The practical application of this would be an exemption from the law ...
According to the understanding of many commentators "pru u'revu" (be fruitful and multiply) is a positive commandment which is not fulfilled unless a man has both a son and daughter as offspring. ...
The commandment to "Be fruitful and multiply" was given to Adam HaRishon. Why, then, is this not included in the Sheva' Mitzvoth Bnei Noaḥ?