In which of the following is $Bidder's$ canal present?

The blastula of a frog contains:

The concept that the organiser is essential for embryonic development was given by,or for the 'Theory of organiser',the Nobel Prize was given to:

The third cleavage in frog's development is

If the ectoderm from the neural tissue area is removed from the embryo and transplanted in place of the presumptive belly ectoderm,the embryo will develop:

During embryonic development,the establishment of polarity such as anterior/posterior,dorsal/ventral,and medial/lateral axes is called: