​The early embryonic development in amphibians and aves serves as two different model plans of development. In the former, the germ layer formation is initiated from a fluid-filled ball-like blastula, while in the latter the germ layer formation is initiated on a flat blastodisc. Given below are some of the terms for amphibian embryo in column I and from avian embryo in column II:​

​Which of the following is the all-correct match of Column I with Column II?​

Correct option is B

Explanation-

A. Blastocoel → iv. Between epiblast and hypoblast
In both amphibians and avians, the blastocoel is a fluid-filled cavity. In birds, the blastocoel forms between the epiblast and hypoblast, matching option iv.
B. Blastopore lip → ii. Primitive streak
The blastopore lip in amphibians is the site of gastrulation initiation.  Its avian equivalent is the primitive streak, where cells ingress to form mesoderm and endoderm.
C. Dorsal lip of blastopore → iii. Hensen’s node
The dorsal lip of the blastopore in amphibians is the organizer region, which initiates axis formation. Hensen’s node is the functional equivalent in birds — also an organizer.
D. Blastopore → v. Primitive groove
The blastopore is the opening through which cells move during gastrulation. In birds, this is functionally equivalent to the primitive groove (a groove within the primitive streak through which cells ingress).
E. Nieuwkoop center → i. Posterior Marginal Zone (PMZ)
The Nieuwkoop center in amphibians is a signaling center that induces the organizer. In birds, the Posterior Marginal Zone (PMZ) serves a similar role, initiating primitive streak formation by signaling to Koller's sickle and the epiblast.

 Final Answer:
A → iv
B → ii
C → iii
D → v
E → i

Correct answer - Option b -​A-iv, B-ii, C-iii, D-v, E-i