Top 10 unbelievable historical concurrencies. A zygote is a single cell which has formed as the result of the merging of an egg cell and a sperm cell. In other words, it's a fertilized egg, with the potential to develop into a living organism.
Gastrovascular system of the flatworm Dugesia, colored yellow. The gastrovascular cavity is the primary organ of digestion and circulation in two major animal phyla: the Cnidaria (including jellyfish and corals) and Platyhelminthes (flatworms). The cavity may be extensively branched into a system of canals. In cnidarians, the gastrovascular system is also known as the coelenteron, and is commonly known as a blind gut or blind sac, since food enters and waste exits through the same orifice.
The nasal cavity is part of the human respiratory system. Also known as the nasal fossa, it is a small air-filled chamber behind the nose, connected via the pharynx to the l â¦ arynx (voicebox) and the trachea.Above and in front of the nasal cavity are the sinuses (paranasal cavities), located inside the facial bones.he nasal cavity is part of the human respiratory system. Also known as the nasal fossa, it is a small air-filled chamber behind the nose, connected via the pharynx to the l â¦ arynx (voicebox) and the trachea.