noun
: differentiation of a tissue or structure in response to factors outside itself (as differentiation of ectoderm into a lens in the presence of an optic cup)
noun
: differentiation of a tissue or structure in response to factors outside itself (as differentiation of ectoderm into a lens in the presence of an optic cup)
Webster's New International English Dictionary. Новый международный словарь английского языка Webster. 2012