Living things are broken down in to 8 levels from smallest to largest.
1. Atoms: All things are made up of atoms.
2. Molecule: Two or more atoms together. Ex: A water molecule is made up of 2 hydrogen atoms and 1 oxygen atom.
3. Organelle: Organelles are parts of a cell that have certain roles to help the cell to properly function. Examples: nucleus, cytoplasm, endoplasmic reticulum
4. Cells: All living things are made up of cells. Cells are the smallest unit of living things.
5. Tissue: A bunch of the same cells together will form a type of tissue and different tissues perform different functions. Example: brain tissue
6. Organ: When a group of tissues combines they can form an organ. Each organ performs a different function. Example: Your heart is made up of several types of tissues.
7. Organ system: When a group of organs combine they form an organ system. Example: your digestive system is made up of your esophagus, stomach, small intestine and large intestine
8. Organism: An individual living thing such as you! Other examples: cat, dog, fish
