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

The beginning of archenteron formation in the development of a frog represents which stage?

At which stage of embryonic development is the fate map prepared?

What type of cleavage occurs in mesolecithal eggs?

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:

Metamorphosis in frog is fastened by