HW9-23___Chp43_Gastrulation__Neurl_Dev.__STUDENT_VERSION

Free Response 1 (5 points) : Diagram the correct primary induction process in frogs making sure to include the blastocoel, ventral lip, yolk plug, dorsal lip, and “neuralizing” factors. Is primary induction in the formation of the neural plate associated with positive or negative factors? Explain. Free Response 2 (5 points) :In class we learned about a protein called Sonic hedgehog (Shh) and its relation with the function and the development of the neural tube. What tissue/structur produces this protein? What do the release of this protein and BMP lead to? What does the Shh activate and how is this related to the motor neuron formation? , blastoco "neutralizing" factor e - dorsal lip I & yolk plug ventral lip Primary induction in the formation of the neural plate is associated with positive factors because the signal from the motorchord instructs the overlying epithilium to become neural. 2) Shh is produced by the notochord. The release of Shh and BMP leads to gradients of growth factors in the developing neural tube. Shh activates a receptor in neural tube cells and directs motor neuron formation.