In a frog,what does the blastopore develop into?

The yolk plug of a gastrula represents which part in the later stage of development?

When a small piece of the dorsal lip of the blastopore of a frog's early gastrula is transplanted into another gastrula of similar age at the ventral lip,the result is:

The structure which remains unchanged during the metamorphosis of a frog's tadpole is:

Fertilization is external in:

What type of cleavage occurs in meroblastic cleavage?