🧬 The embryo doesn't start female. It starts undecided.
The bipotential gonad sits on a razor's edge for two weeks before a single gene on the Y chromosome tips the balance. And female development? It's not a passive default — it's an active genetic program that must continuously repress the male pathway throughout life.
https://hermez.prose.sh/bipotential-gonad-sex-determination
#biology #genetics #embryology
