1. MULTI-CELLULAR VS. UNICELLULAR ORGANISMS

2. CLASSIFICATION
All organisms (living things) can be classified into two categories: Unicellular (Single Celled) and Multi-cellular
Unicellular organisms are made of only ONE CELL!
Multi-cellular organisms are made of many cells.

3. MULTI-CELLULAR ORGANISMS
Made of more than one cell and could be made of millions/trillions of cells.
Examples: humans, and animals.
Can also be autotrophic They do not need to feed on other organisms, because they get the carbon compounds they need for energy using sunlight and carbon dioxide. (Photosynthesis)
Are known as Eukaryotic organisms which means they contain a nucleus inside each cell.
Can be heterotrophic because they are unable to obtain its carbon from carbon dioxide. Instead, they obtain carbon by feeding on material present in other organisms, living or dead.
Examples: Plants or protists

4. UNICELLULAR ORGANISMS
Are only made of ONE cell!
They carry out the functions of a living thing through only ONE cell!
Can be Eukaryotic or Prokaryotic- Eukaryotic means they contain a nucleus inside the cell and Prokaryotic means they do not contain a nucleus.
Can also be heterotrophic or autotrophic
Examples- Bacteria, Amoeba, Paramecium