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In higher organisms, gametes are of two distinct types: large immobile ones known as eggs or egg cells (see ovum) and small ones known as sperm. They come together at fertilization. In some lower organisms the gametes are all the same, or they may belong to different mating strains but have no obvious differences in size or appearance.
The Pillars of Hercules represent the promontories of Gibraltar and Ceuta. The shield represents the regions of Castile, Léon, Aragón, Navarre, and Granada. Effective date: 18 December 1981.
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