Immune System
smooth muscle
A rock is a complex mixture of compounds, not a pure substance.
an element
complex reaction time is a stimulus response
Major histocompatibility complex proteins that protect cells from invasion
The structure that is responsible for the restriction of movement of large complex substances into the bloodstream of your body is the brain.
by producing an immune response
a complex and usually unpleasant emotional response to isolation.
If a substance didn't turn blue or black with iodine, it means that it didn't form any complex with iodine. When iodine forms a complex with the substance, the complex is generally blue in color.
The even more complex biochemical machinery of the Cell, which is responsible for the manufacture, maintenance and removal of [spent] complex proteins.
Wood has a complex composition; it is not only a compound.
Complex Source mastering biology