as darwin observe the finchs hr came to the conclusion that they all had a since all the birds were simlair

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.

colors do exist. the color of the sky is actually violet; humans percieve the color of the sky as blue.

haha

it's made from mineral oil