Concentration:
the amount of a substance within a of another
substance

Volume

Explanation:

In chemistry, the CONCENTRATION of a solution is the amount of a substance present within a volume of another substance. In other words, the concentration refers to the amount of a solute dissolved in a particular volume of a solvent to make a solution.

Concentration can be expressed in mass per volume i.e. g/cm³ or mol per volume i.e. mol/L or mol/dm³ etc. The amount of a substance is measured in Mass or mole, while the volume of a substance in Litres (L).

it is a learned trait

explanation:

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.