While the tadpoles of competing species may complete metamorphosis in as little as just a few short months, Bullfrog tadpoles can remain in the same state for as long as one to two years before they actually become adult frogs.
Two types of white blood cells called lymphocytes are vital to the specific immune response. Lymphocytes are produced in the bone marrow, and mature into one of several subtypes. The two most common are T cells and B cells. An antigen is a foreign material that triggers a response from T and B cells.
Lymphocytes are a type of white blood cell. There are B and T type lymphocytes. 1  B lymphocytes become cells that produce antibodies. 2  Antibodies attach to a specific antigen and make it easier for the immune cells to destroy the antigen. 3  T lymphocytes attack antigens directly and help control the immune response.here are B and T type lymphocytes. 1  B lymphocytes become cells that produce antibodies. 2  T lymphocytes attack antigens directly and help control the immune response.