Development

 

41.1 Fertilization and Early Division

Sea Urchin Egg Cell

Sea Urchin Fertilization

Sea Urchin Cleavage and 2 Cell Stage

Sea Urchin 4 Cell Stage

 

Starfish Morula

Starfish Blastula

Starfish Gastrula

  

 

 

41.2 Frog Development

Unfertilized Frog Eggs

Early Neurula Stage

Early Tadpole (about 96 hours)

Tadpole (about 5 days)