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.
1 Nasal cavity â is part of the respiratory system. 2  Located within the nose (and posterior). 3  Orbital cavities â house the eyes. 4  Oral cavity â the mouth, contains the teeth and gums. 5  Synovial cavities â surround freely movable joints and secrete a lubricating fluid like serous membranes.he superior division is called the thoracic cavity. The thoracic cavity is surrounded by the ribs and muscles in the chest. Itâs further su divided into lateral pleural cavities (each pleural cavity envelopes a lung) and the mediastinum.