From bricks to building
Bricks form walls, walls form rooms, rooms form a house — and cells form tissues, tissues form organs, organs form you. The body is organized in these nested levels, each built from the simpler one beneath it.
Building the body, level by level
The body is organized in a hierarchy: cells form tissues, tissues form organs, organs form systems, and systems together make the organism. Each level does a job the level below cannot do alone.
Homeostasis
Homeostasis is the body keeping its internal conditions — temperature, blood sugar, pH — steady despite a changing outside world.
Lab · Order the hierarchy
- Write these out of order: organ, cell, system, tissue, organism.
- Arrange them from smallest to largest.
- Give one example at each level (e.g., muscle cell → muscle tissue → heart → circulatory system → human).
What you should see: Cell → tissue → organ → system → organism. Each level is built from many of the one before it.