Answer:
Molecules
Explanation:
Every living thing is made up of cells; it is the basic functional unit of every living being.
When cells group up, they form a tissue (epithelial tissue, elastic tissue etc.). Several different tissues make up an organ and different organs with mutual function make up an organ system.
But those are all higher levels of organization.
Cell is also comprised of things that are called subcellular level of organization.
Everything that exists is comprised of atoms, atoms make up molecules, and molecules make up organic and non-organic compounds. These compounds make up organelles, nucleus, cell matrix and cell wall; the very basic and essential parts of the cell.
