Cell Organisation
This lesson covers:
- The grouping of cells into tissues, organs, and organ systems
- How tissues, organs, and organ systems form a multicellular organism
- Examples of cell organisation in plants and animals
Principles of cell organisation
In complex multicellular organisms like animals and plants, the cells do not work alone.
They are organised into increasingly complex structures like tissues, organs and organ systems.

- Tissue - A group of similar cells that perform a specific function.
Examples in humans include muscle tissue, nervous tissue, connective tissue, and epithelial tissue.
- Organ - A structure made of various tissues that work together.
Examples in humans include the heart, lungs, liver, and stomach.
- Organ system - Multiple organs cooperating together as a system.
Examples in humans include the circulatory system, respiratory system, digestive system, and nervous system.
- Multicellular organism - An organism made up of multiple organ systems.
An example is a human.
Organisation in multicellular organisms
Cells come together to form tissues, organs, organ systems, and eventually forming a multicellular organism.
Organisation in humans

As an example in humans:
- A muscle cell works together with other cells to form muscle tissue.
- Muscle tissue and other tissues form an organ called the stomach.
- The stomach works with other organs to form the digestive system.
- The digestive system and other systems form the overall human organism.
Organisation in plants

As an example in plants:
- A palisade cell works with other cells to form leaf tissues.
- Different leaf tissues work together to form an organ called the leaf.
- Leaves work with other organs like the stem to form a transport system.
- The transport system and other systems form the overall plant organism.