An estrogen-dependent breast cancer cell line is grown in a medium that contains estrogen.Cell proliferation is monitored over time.In a separate experiment,the cell line is grown in a medium that lacks estrogen but includes bisphenol A,a compound found in polycarbonate plastics.When monitored,cell proliferation is higher than in the presence of estrogen.A possible explanation of these results is that bisphenol A
A) inhibits the binding of estrogen to the estrogen receptor.
B) is an agonist of the estrogen receptor.
C) inhibits adenylate cyclase.
D) is toxic to the cell line.

Question

Quizplus · Accepted Answer

Bisphenol A is acting as an agonist of the estrogen receptor, mimicking the effect of estrogen and promoting cell proliferation. The fact that proliferation is higher in the absence of estrogen suggests that bisphenol A is binding to the receptor even when estrogen is not present.

An Estrogen-Dependent Breast Cancer Cell Line Is Grown in a Medium