stages of embryonic development: etapa1: a sperm meets an egg in a tube, try crossing your menbrana, if cnsigue the egg produces a very tough cover q prevents the penetration of a second fertilization cncluye espermatozoide.la CNDO nuclei of sperm and egg merge. ai apartir start embryonic development, Stage 2: the zygote formed a single cell x, move x the tube on its way to the uterus and begins to divide. the end of the 2 day already formed two cells x q are kept together. etapa3: cntinuan cells divide to form an embryo of 32 cells called the morula. etapa4: a cavity formed within the morula q takes the form of a hollow ball, a sta structure is called the blastocyst stage. etapa5: a group of cells inside dl cndensa blastocyst and form a compact mass disposed at one end, so it is called tardio.las blastocyst inner cell mass originated the embryo itself, ie all tissues and cells change organos.en cover external structures will produce the embryo. etapa6: the embryo is implanted in the uterine wall has been prepared to q ste event covered with a layer named endometrio.este process continues until day 14 after fertilization.