Which part of the adaptive immune response involves b cells?

Humoral immunity

Explanation:

Adaptive immunity is of two types: cell-mediated immunity and antibody-mediated immunity. Antibody-mediated immunity includes B cells. The function of B cells is to transform into plasma cells which in turn form antibodies. Antibodies are also called immunoglobulins and bind with a specific antigen to generate an immune response. Body fluids or humor include blood and lymph. Since the antibodies bind to the antigens in body fluids (blood and lymph), the antibody-mediated immunity is also called humoral immunity.

cells use diffusion to get substances in and out of themselves. that diffusion will occur across the cell membrane or the outer covering of the cell. because we are talking about the surface of the cell, surface area and volume are  important factors here. as a cell increases in size, its surface area and volume increase as well.  we call that the surface area to volume ratio (sa: vol).  but the catch is that  volume increases at a greater rate than surface  area. in other words, as a cell gets bigger, the sa: vol gets smaller. so a really small cell like bacteria is mostly cell membrane (surface) with very little contents (volume). a really big cell like an egg, is mostly insides with a super thin membrane. so what ends up happening is that the cell cannot efficiently diffuse all of the stuff it needs in/out to survive. therefore cell size is limited to about 100mm. so how do we make organisms bigger than 100mm? cells divide! by dividing and becoming multicellular, organisms are able to grow!   check out the diagrams i attached to see the effect of sa: vol. i hope this ! good luck!