Which one of the following statements with respect to amphibian development is correct?
1
The organizer is itself induced by the Nieuwkoop Centre located in the dorsalmost mesodermal cells.
2
The organizer functions by secreting proteins like Noggin, Chordin and Follistatin that blocks BMP signal that would otherwise dorsalize the mesoderm.
3
In the presence of BMP activators the ectodermal cells form neural tissue.
4
Wnt signalling causes a gradient of β- catenin along the anterior-posterior axis of the neural tube that appears to specify the regionalization of the neural tube.
5
Question Not Attempted