Undifferentiated embryonic cells, a term mostly used in foreign literature.

Undifferentiated cells resulting from cleavage of a fertilized egg (ZYGOTE). Inside the intact ZONA PELLUCIDA, each cleavage yields two blastomeres of about half size of the parent cell. Up to the 8-cell stage, all of the blastomeres are totipotent. The 16-cell MORULA contains outer cells and inner cells.

Synonyms: Blastomeres, Blastocyte, Blastocytes, Blastomere