Final answer:
Noggin, chordin, and follistatin are BMP antagonists involved in proper embryonic development by inhibiting the activity of BMPs, allowing for proper dorsal structure formation including the neural tube.
Step-by-step explanation:
Noggin, chordin, and follistatin all have in common that they are BMP antagonists. These proteins play a critical role during early embryonic development where they inhibit the activity of bone morphogenetic proteins (BMPs). This inhibition is crucial for the proper development of the dorsal structures, such as the neural tube, by preventing the BMPs from signaling ectodermal cells to become epidermal cells and instead allowing these cells to contribute to the formation of the neural plate. This mode of action contrasts with the Wnt signaling pathway, which typically operates to signal ectodermal cells to form the epidermal cells and the neural plate. The fact that these proteins are BMP antagonists points to how cell signaling and regulatory pathways are conserved across species, emphasizing their importance in developmental biology. The interaction between these antagonists and BMPs is an example of how extracellular factors can influence cell fate and morphogenesis during embryogenesis.