Severe cases can even lead to death. Best way to protect yourself from getting the flu? Get an annual flu shot. When is flu season? The flu season occurs in the fall and winter, but the virus can stay active year-round. Is the flu virus contagious? Yes, it is very contagious. You can have the flu for 1 to 4 days before you start feeling sick.
Some mollusks have bilateral symmetry. Mollusks include gastropods such as snails, bivalves such as oysters, and cephalopods such as squid. Some bivalves have bilateral symmetry. Some mollusks have bilateral symmetry. Mollusks include gastropods such as snails, bivalves such as oysters, and cephalopods such as squid.
Sea stars or starfish are marine invertebrates belonging to Kingdom Animalia and phylum Echinodermata, class Asteroidea. The names sea star and starfish are also used for the closely related brittle stars, which make up the class Ophiuroidea. They exhibit a superficially radial symmetry. Starfish typically have five or more arms which radiate from an indistinct disk (pentaradial symmetry). In fact, their evolutionary ancestors are believed to have had bilateral symmetry, and sea stars do exhibit some superficial remnant of this body structure.