Hans Spemann and colleagues developed the concept of the primary organizer in amphibian embryos while studying the
A) medial cells between the optic cups.
B) anterior terminus of the notochord.
C) lateral margins of the neural tube.
D) posterior edge of the dorsal ectoderm.
E) dorsal lip of the blastopore.

Question

Quizplus · Accepted Answer

Hans Spemann and colleagues developed the concept of the primary organizer in amphibian embryos through their studies of the dorsal lip of the blastopore. They found that this region contained cells that were able to induce the formation of a second embryonic axis when transplanted to another part of the embryo, indicating that it played a crucial role in early development.

None of the other options listed were specifically linked to the concept of the primary organizer. The medial cells between the optic cups are involved in eye development, but not in the formation of the primary organizer. The anterior terminus of the notochord is important for organizing the neural plate, but it is not the primary organizer. The lateral margins of the neural tube are involved in neural crest cell formation, but not in the primary organizer concept. The posterior edge of the dorsal ectoderm is important for the formation of the spinal cord, but again, it is not directly linked to the primary organizer concept.

Hans Spemann and Colleagues Developed the Concept of the Primary