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Fecundation can be defined as the encounter and fusion of two gametes cells forming a new individual. Fertilization is divided in some parts, the passage of the sperm through the radiate corona, penetration of the spermatozoid in the zona pellucida, reaction acrossomic and fusion of the membranes of the oocyte and the spermatozoa, and soon afterwards the nesting that is the fixation of the already fertilized ovule On the wall of the uterus.   Reference: GARCIA, sonia. FERNANDEZ, casemiro. Embriologia3°ediçao. 659paginas

Animal cell is a eukaryotic cell in animals, they are larger and structurally more complex and contain much more DNA, is cracked by the richness of its membranes. It composed of several cytoplasmic organelles where each one plays an important role for its functioning.  Nucleolus:  production of ribosomal components. Core : preserve and transmit genetic information.  Ribosomes:  protein production.  Rough endoplasmic reticulum:  protein transport.   Smooth   endoplasmic reticulum:  cellular transport, lipid synthesis.  Vesicles : transport of substances.  Golgi complex:  makes cell secretion.  Cytoskeleton:  transport of substances and give shape to. Mitochondria:  cellular respiration.  Vacuole:  intracellular digestion.  Cytoplasm:  store substances. Lysosomes:  digestion of organic substances.  Centrioles:  Cytoskeletal organization and movement of...

The blastocyst is an embryo formed between 4° to 5°days after the fertilization. We can observe the formation of blastula consisting of a set of cells and the formation of a central cavity, the blastocele.  The cells of the inner man cell, now called the embryoblast, are located in poles, while those of the outer mass the trophoblast flatten and from the epithelial wall of the blastocyst. The internal cell mass will give rise to the tissues of the embryo itself, while the external cell mass would from the trophoblast that later contributed to the formation of the placenta.  Reference:SADDLER, T. W. Embriologia Médica,7.ed. Editora Longman, 1995