[Solved] A woman's natural testosterone level drops with the removal of ovaries or A) erotic plasticity. B) refractory periods. C) the adrenal glands. D) the anterior commissure. Placenta: A structure that forms within the womb during pregnancy, supplying the developing fetus with oxygen and nutrients, and eliminating its waste. Nonshared Environmental Effect: Refers to the environmental factors that contribute to the differences in development among siblings within the same family. Teratogens: Substances or factors that can cause congenital deformities or developmental abnormalities in an embryo or fetus. Blastocyst: An early stage in the development of an embryo, consisting of a sphere of cells surrounding a fluid-filled cavity, before implantation in the uterus.