Predators often feed on weak or
sick animals in an ecosystem. the
role of the predator is described as
its ..what? : )

Predators are above all other organisms below it.  Usually as one moves up the

food chain, certain chemicals are concentrated as they move up the food chain.

Examples of this are mercury and PCB.

I THINK the correct answer would be Niche.

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.

lunar landing mission. apollo 11 was the first manned mission to land on the moon. the first steps by humans on another planetary body were taken by neil armstrong and buzz aldrin on july 20, 1969. the astronauts also returned to earth the first samples from another planetary body.

explanation: