The blastopore develops into the future

The third cleavage of frog development is:

In which of the following animals is cleavage restricted to a small portion of the animal pole of the egg?

In frogs,the chromosome number is reduced to half during which of the following stages?

The point of sperm entry during fertilization in amphibian eggs forms:

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: