Which of the following is NOT a type of T cell?

A. Forming a large number of cytotoxic cells:Cytotoxic cells are produced by T lymphocytes, notB cells. B cells respond to antigens primarily by producing antibodies and memory cells, not cytotoxic T cells.

B. Immediately producing antigen-specific antibodies:B cells require activation and clonal expansion before producing significant amounts of antibodies. The response is not instantaneous; there is a latent period during the primary immune response.

C. Producing progeny cells that include plasma cells and memory cells:Upon activation, B cells undergo clonal selection and differentiate into plasma cells, which secrete antibodies, and memory B cells, which provide long-term immunity. This is the hallmark of the primary adaptive immune response.

D. Reducing its size:B cells do not shrink in response to antigen exposure. Instead, they proliferate and differentiate to mount an effective immune response.

A. Lymph nodes:Lymph nodes provide sites where B lymphocytes can encounter antigens and become activated, but they do not directly release antibodies. They function mainly as filtering and immune activation centers.

B. T lymphocytes:T cells mediate cellular immunity by directly attacking infected or abnormal cells or helping activate other immune cells. They do not produce antibodies themselves.

C. Medullary cords:Medullary cords are structures within lymph nodes that contain plasma cells and macrophages. While they house antibody-producing cells, they do not themselves secrete antibodies.

D. B lymphocytes:B cells differentiate into plasma cells upon activation. While they can produce some antibodies initially, the bulk antibody secretion is carried out by the plasma cells they generate.

E. Plasma cells:Plasma cells are fully differentiated B lymphocytes specialized for antibody production. They secrete large quantities of antibodies specific to a particular antigen, making them the primary source of circulating antibodies in adaptive immunity.