You are here
From Cell to Organism
- The cell is the basic unit of life.
- A group of similar cells forms a tissue.
- Different tissues form an organ.
- Several organs form an organ system.
- All the organ systems together make an organism.
Example 1 — The Stomach
- Muscle tissue and lining tissue form the stomach.
- The stomach is an organ.
- It joins other organs to form the digestive system.
Example 2 — A Whole Plant
- Plant cells form tissues, then organs like leaves and roots.
- These organs form systems in the plant.
- Together they make the whole plant organism.
Important Points
- The order is: cell → tissue → organ → organ system → organism.
- Organisms made of many cells are called multicellular organisms.
Definition — Tissue
A tissue is a group of similar cells that work together to do a particular job.
Definition — Multicellular Organism
A multicellular organism is a living being made up of many cells, like a plant or an animal.
🏭 Ever Heard Of — The Largest Cell
The yolk of an ostrich egg is a single cell, the largest known cell in the living world.
It measures about 130 to 170 mm across. The egg also has a shell for protection and a white liquid that feeds the cell as it develops.
