Many signaling molecules found in the frog organizer have also been found in the chick embryo's
A) primitive neural tube.
B) primitive groove.
C) Hensen's node.
D) endoderm.
E) hypoblast.

Question

Quizplus · Accepted Answer

The Hensen's node in the chick embryo is similar to the dorsal lip of the blastopore found in the frog embryo, and it is the region where the organizer forms. Many signaling molecules found in the frog organizer have also been found in the Hensen's node, suggesting a similar role in axis formation.

Answer: A
 The primitive neural tube is the precursor to the central nervous system and it forms from the ectoderm. Many signaling molecules found in the frog organizer, such as BMP and noggin, are crucial for neural tube formation in both frogs and chicks.

Many Signaling Molecules Found in the Frog Organizer Have Also