Mulberry embryo and blastocyst are actually different developmental stages after the formation of a fertilized egg. Because after the sperm and egg unite, the fertilized egg will be formed, and after the fertilization of the fertilized egg, the cell differentiation will begin, from a fertilized egg cell gradually differentiate into 2 cells, 4 cells, 8 cells, 16 cells, 32 cells and so on. When the number of differentiated cells reaches 32, the embryo is named mulberry embryo because the shape of the embryo is similar to that of a mulberry. With the continuous development of the mulberry embryo, an embryo with a certain cavity in the middle will be formed, which belongs to the stage of blastocyst, mulberry embryo and blastocyst are different stages of the development of the fertilized egg, and mulberry embryo appears earlier than blastocyst. Generally, the appearance of mulberry embryo is about 72 hours after fertilization, and the appearance of blastocyst will be about 96 hours.