The role of Chordin and Noggin in patterning in developing vertebrates is equivalent to that of …(1) in Drosophila. They are secreted from the …(2) pole and antagonize the activity of bone morphogenetic factors that are secreted throughout the embryo.
A) 1: Decapentaplegic; 2: dorsal B) 1: Decapentaplegic; 2: ventral C) 1: Short gastrulation; 2: dorsal D) 1: Short gastrulation; 2: ventral