Why the cells don’t just continue to grow larger as organisms grow larger

There are two main reasons why cells divide rather than continuing to grow larger and larger: ... more demands the cell places on its DNA. If the cell grows too large, it will have trouble moving enough nutrients and wastes across the cell membrane.

white blood cells or wbc s are mainly 2 types-

1.agranulocytes

2.granulocytes

the monocytes or macrophages of agranulocytes , dendritic cells which are accessory leucocytes, and b cells which is one type of lymphocytes   identify the antigens present on the pathogen's surface. these three cells are called antigen presenting cells(apc) which are phagocytes and destroy the antigens by secreting antitoxins. besides this leukocyte is always plays vital role in the immunity of the body.