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.
Most bivalve mollusk shells, like clams, are mirror images of each other. Brachiopod shells are both unlike and unequal. Brachiopods have a larger ventral shell (pedicle valve) and a smaller dorsal shell (brachial valve).The symmetry of the brachiopod is through both shells instead of between shells as in mollusks.ost bivalve mollusk shells, like clams, are mirror images of each other. Brachiopod shells are both unlike and unequal. Brachiopods have a larger ventral shell (pedicle valve) and a smaller dorsal shell (brachial valve).