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.
Class Gastropoda - Snails and Slugs Primarily marine, with many freshwater and terrestrial forms Most have shell, shell lost in slugs Head possess paired tentacles that may have terminal eyes Visceral mass asymmetrical because of torsion (twisting) during development 120Â° twist results in loss of right gill and positioning of anus to the right of the head