Question

Which structure in the avian embryo is analogous to the dorsal lip of blastopore of the amphibian:

• A. Primitive groove
• B. Area opaca
• C. Hensen's node
• D. Koller's sickle

Hint:

Hensen's Node = The “Boss” (Organizer) of the bird embryo.

Answer 1

The Correct Option is C

Step 1: Concept
Gastrulation in different species involves “organizer” regions that direct development of the primary body axis.

Step 2: Meaning
An analogous structure performs the same developmental function in a different species.

Step 3: Analysis
In amphibians, the dorsal lip of the blastopore is the primary organizer. In birds, Hensen's node at the anterior end of the primitive streak performs the same role.

Step 4: Conclusion
Hensen's node is the avian analogue to the amphibian dorsal lip.

Final Answer: (C)