Unicellular organisms are made up of only one cell. That one cell does everything the organism needs to survive.Examples: Bacteria, Amoeba, Paramecium.Multicellular organisms are made up of many cells. These cells have special functions (like muscle cells, nerve cells, etc.).Examples: Humans, animals, plants.
Unicellular organisms are basically single-celled creatures like bacteria or amoebas. They can do everything they need to survive within that one cell, which is pretty impressive.Multicellular organisms, on the other hand, are made up of tons of cells that work together to form different tissues and organs. Think humans, plants, animals - anything with specialized cells that do different jobs.The big difference is that unicellular organisms are super self-sufficient, while multicellular organisms can get way more complex and do way cooler things because they've got so many cells working together. It's pretty cool to think about how different these two types of organisms are!