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.
Cnidaria. The gastrovascular cavity in Cnidaria is surrounded by an inner tissue layer called the gastrodermis. The outside of the organism has a tissue layer called the epidermis. Between these two tissue layers is a gel-like region called the mesoglea.nimals such as jellyfish, corals and flatworms have a much simpler way to handle the digestion of food, as well as the circulation of nutrients around the body. Learn about the structure and function of the gastrovascular cavity in these organisms.