Apenas a spermatozoon penetrates in vulo. (LOPEZ, 1996 pg. 327). 2.Antes to reach the membrane of vulo, the spermatozoon crosses the pelcida zone. 3.A head of the spermatozoon reaches the plasmtica membrane. The head of the spermatozoon formatted for the nucleus only penetrates. The tail is abandoned of the side of is.

Thus, the nucleus, when crossing the membrane of vulo, forms one fecundao membrane. (LOPEZ, 1996 pg. 327). 4.Com the fusing of the nucleus haplide of the spermatozoon with the one of vulo also haplide forms a Diplide nucleus (2N) and from appears the cell there egg or Zygote. The fecundao process is complete. (LOPEZ, 1996 pg. 327). From the union of the spermatozoon and vulo it has beginning not only the fecundao process, but, also, the beginning of the life.

5.Aps the fecundao, the egg suffers successive mitticas divisions that originate some cells that remain joined; thus the initial development of the embryo starts. Exactly with the increase of the frame number it does not have increase of the total volume, period called segmentation. (LOPEZ, 1996 pg. 327). 6.A phase in sequence is the gastrulao. In this phase, the increase of the frame number is folloied of the increase of the total volume. Still in this phase the germinativos or embryonic brochures are formed, that will give origin to fabrics of the individual. (LOPEZ, 1996 pg. 327,328). 7.O third period of the embryonic development after the fecundao is organognese where the differentiation of the agencies occurs. A time is enough to understand the importance of the union of its cells that such act is the beginning of a future human being. (LOPEZ, 1996 pg. 327,328). The Embryo and the Ethics Each individual can present a distinct reflection on the embryos. In such a way, to guide the thought and the quarrel, we suggest the visualization of the embryo from two distinct optics: the 1) embryo as a cellular entity with potential multiples for the research and unprovided of any conscience of its existence or, 2) to think about the embryo as a human being in potential, endowed with perspectives and possibilities.