In mammals the chorion and the allantois together form

When mouth develops from blastopore, the organism is called

During early and middle fetal life, the testis are located in the

In human, beings, after .............. month of pregnancy, the embryo's heart is formed.

During embryonic development, the establishment of polarity along anterior/ posterior, dorsal/ventral or medial/lateral axis is called

Seminiferous tubules develop central lumen after