1. Early stage of an embryo produced by cleavage of an ovum; a liquid-filled sphere whose wall is composed of a single layer of cells; during this stage (about eight days after fertilization) implantation in the wall of the uterus occurs
   - blastosphere

Derived forms: blastulae, blastulas

See also: blastular

Type of: conceptus, embryo, fertilised egg [Brit], fertilized egg

Encyclopedia: Blastula

• bottom-dweller
• bottom-dwelling
• bottom-feeder
• bottom-feeding
• bottom-up
• bottomed
• bottomland
• bottomless
• bottomlessness
• bottommost
• bottoms up
• botuliform
• botulin
• botulinal
• botulinum
• botulinum toxin
• botulinum toxin A
• botulinus
• botulinus toxin
• botulism
• botulismotoxin
• bouchee
• bouclé
• boudoir
• bouffant