Ascientist plans to find out the cause of decrease in bird population in a location. he interviews 50 people who work in the local oil mine and 45 of them believe that the mine does not affect the birds. the scientist concludes that 90 percent of people in the location believe that the local oil mine does not cause decrease in bird population. why is the scientist's conclusion most likely unreliable?

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.