Answer
The levels of human structural complexity from organism (most complex) to atom (least complex) are:
1. Organism (composed of organ systems)
2. Organ System (composed of organs)
3. Organ (composed of tissues)
4. Tissue (composed of cells)
5. Cell (composed of organelles)
6. Organelle (composed of molecules)
7. Molecule (composed of atoms)
8. Atom
Work Step by Step
We can see this organization because the higher complexity structure is consisted of numerous lower structure units in order for it to function. For example, an organ system consists of multiple organs, which needs tissues, which needs cells and so on.
