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

Metamorphosis in frog is fastened by

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 fifth cleavage of the fertilized egg of a frog results in the formation of: (in $cells$)

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

Which of the following drugs inhibits metamorphosis in frogs?