In some embryos, the daughter blastomeres are either above or to the side of each other. This is said to be radial-type symmetry. In some embryos, the daughter blastomeres are not direclty over or beside each other. They are tilted to the left or right 45 degrees. This latter cleavage symmetry is said to be spiral.
![]() | This is an animated gif. (No movement? Click Reload/Refresh) |