Hierarchy of Life for Fungi, Protists, Plants, and Animals

1. Fungi and protists may be unicellular or multicellular depending on the species.

1.1. A unicellular organism is composed of one cell.

1.1.1. Each cell contains membrane-bound organelles (or an endomembrane system) and thousands of different molecules.

1.1.1.1. Each organelle is composed of molecules.

1.1.1.1.1. Each molecule is composed of atoms.

1.2. A multicellular organism can be composed of tissues.

1.2.1. Each tissue is composed of cells.

1.2.1.1. Each cell contains membrane-bound organelles (or an endomembrane system) and thousands of different molecules.

1.2.1.1.1. Each organelle is composed of molecules.

2. Molecules include both macromolecules and smaller molecules.

3. Common atomic elements include CHONPS.

4. Plants and animals are multicellular organisms that are composed of organ systems.

4.1. Each organ system is composed of organs.

4.1.1. Each organ is composed of tissues.

4.1.1.1. Each tissue is composed of cells.

4.1.1.1.1. Each cell contains membrane-bound organelles (or an endomembrane system) and thousands of different molecules.