Correct option is A
The correct answer is (a) epiblast and hypoblast
Explanation:
In the avian embryo, the blastocoel-like fluid-filled cavity is formed between the epiblast and hypoblast. The epiblast is the upper layer of the embryo, while the hypoblast is the inner layer. Together, these two layers create the cavity known as the blastocoel, a structure critical for early development.
Information Booster:
The epiblast is responsible for forming the outer layer of cells, which later develops into various tissues.
The hypoblast is the inner layer of cells and plays a crucial role in forming extra-embryonic structures.
The formation of the blastocoel is essential for proper embryo development in birds.
The epiblast and hypoblast are derived from the inner cell mass of the developing embryo.
The blastocoel serves as a fluid-filled space for the embryo to grow and develop.
This process is vital for the organization of the primary germ layers during embryonic development.
Additional Information:
(b) hypoblast and yolk: The yolk provides nutrients to the developing embryo but does not form the blastocoel-like cavity.
(c) primary hypoblast and secondary hypoblast: These layers are part of the early embryonic stages but do not form the fluid-filled cavity.
(d) Koller’s sickle and Posterior Marginal Zone: These are involved in signaling during early development but are not responsible for the formation of the blastocoel-like cavity.
