Describe the functions of t cells and b cells.

T cells ( The thymus cells) and B cells ( The bone marrow) are the major cellular components of the adaptive immune response . T cells are involved in cell- mediated immunity , whereas B cells are primarily responsible for humoral immunity

Explanation:

Your body can produce the most effective weapons that are against the invaders, which may be bacteria, viruses or parasites. Other types of T-cells recognise and kill virus-infected cells directly. Some help B-cells to make antibodies, which circulate and bind to antigens. A T-cell (orange) killing a cancer cell (mauve).

not necessarily. higher fitness requires the organism to be reproductive successful. for example, an organism at age 10 with 15 offspring is much more fit than an organism at age 15 with only 5 offspring.