This experiment is carried out to observe the development of quail embryos in different days. The quail embryo usually develops and hatches in 20-21 days. We conducted the experiment until day 15, i.e. with 16 eggs in total. During the experiment, all quail embryos were incubated. The reason for incubating embryos is that fertilized eggs can easily be kept in humidified incubators and during the early stages of development, the embryos float on the egg yolk which uses for nutrition. As the embryo grows, it sinks into or below the yolk. The regular appearance of the somites made it possible to precisely observe the stages of the embryo. Say no to plagiarism. Get a tailor-made essay on "Why Violent Video Games Shouldn't Be Banned"? Get an original essay The number of quail embryos up to day 9 is 16 eggs, this is because the conditions of the embryo make them suitable to develop well within these days. The development of the amniotic cavity, which will surround the embryo, occurs. This protects the embryo and allows it to move. The appearance of the allantoic vesicle occurred which plays an important role in calcium reabsorption, respiration and waste storage. Although all embryos are incubated in the same incubator, there are still some differences between them, for example, some of them may be contaminated before being stored in the incubator. Contamination can occur in many ways, for example the embryo has been exposed to surrounding bacteria and fungi, and a piece of broken eggshell contained in the embryo prevents them from developing well. Because of this, the number of quail embryos has been decreasing day by day. On day 10, the number of quail embryos dropped to 8 total. Half of them were dead. The embryo produces an unpleasant odor and must be thrown away. In the embryos that still survived, the vitelline membrane covered almost the entire yolk. Eye pigmentation is easily visible. The upper and lower parts of the beak are differentiated, as are the wings and legs. The neck lengthens and the brain settles completely in its cavity of the external auditory canal. On days 11 to 13, the number of quail embryos that survive is 5 in total. The surviving embryo already has the appearance of claws and the first feather follicles continue to develop. In these phases, the growth of the allantois and the increase in vascularization of the calf occur. Please note: this is just an example. Get a custom paper from our expert writers now. Get a custom essay On day 14, one of the embryos died and all 4 eggs remained. During those days, the nostrils are present as narrow openings and eyelid growth begins to develop. The vitelline membrane completely surrounds the yolk and the feather follicles now cover the lower part of the limbs. On the last day, i.e. the fifteenth day, the eyelid opening takes on an elliptical shape which tends to become thinner. The allantois reaches its maximum size as the calf begins to shrink. The embryo now looks like a quail.