Practice question

Feminization associated with atrazine first documented in northern leopard frogs displaying hermaphroditism in contaminated ponds, but subsequent studies confirmed effects across multiple vertebrate classes including fish such as zebrafish and medaka showing oocyte production in male gonads, reptiles altering temperature-dependent sex ratios, birds reducing male behavior, mammals including rats decreasing testosterone. Conserved steroidogenic pathways involving aromatase and estrogen receptors render many vertebrates vulnerable. Broad phylogenetic conservation of estrogen signaling means atrazine-induced elevation of estrogen synthesis impacts sex determination widely documented among vertebrates broadly, not limited to mammals or insects.