桑そう実じつ胚はいMeanings1nounmorulabiologyA biological term for an early-stage embryo consisting of a solid ball of cells, resembling a mulberry.受じゅ精せい卵らんは分ぶん割かつを繰くり返かえし、桑そう実じつ胚はいを形けい成せいする。The fertilized egg undergoes repeated divisions and forms a morula.