Ключевые слова: 4cell embryo, artificial, baby, biology, blastocyst, cell, cells, cleavage, development, diagram, division, early, egg, egg retrieval, embryo, embryo freezing, embryo transfer, embryology, fertilisation, fertilization, fertilized, fetus, gastrula, genetic, grade embryos, human, illustration, in vitro, ivf, medical, medicine, morula, nucleus, oocyte, prenatal, reproduction, reproductive, research, science, stage, stages, technology, zygote,