Question

Yolk plug can be seen during which developmental stage of frog?

• A. gastrulation
• B. blastulation
• C. cleavage
• D. organogenesis

Answer 1

Answer: (A)

gastrulation

Answer 2

Gastrulation is the process which converts single-layered blastula into $2$ or $3$ -layered gastrula. Gastrulation involves rearrangement of cells due to morphogenetic movements of the cells. The rearrangement forms blastopore through which white spot of yolky endodermal cells are visible, this is called yolk plug. Also, in gastrulation a new cavity called archenteron or primitive gut forms.