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Lesson 1 of 15

Cells with one job

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6 min

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Your body starts as one cell. That cell divides again and again to make billions of cells. The cells do not stay in a heap.

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A heap of four different cells.
Step 1 of 4
  1. A heap of four different cells.
  2. Four more cells — all the same shape, packed edge to edge.
  3. Packed together, they are one tissue.
  4. The heap's cells do not work together: not a tissue.

Rule

A tissue is a group of cells working on one job. They are usually similar.

  • Tissue — a group of cells, usually similar, doing one job.
  • Organ — different tissues working together, like the heart.
  • Organ system — organs working together, like the digestive system.

The order is cell, tissue, organ, organ system, organism. An organism is one whole living thing, like you.

An amoeba is one cell. That one cell does every life job, such as eating and moving. In a plant or an animal, the jobs are shared between cells. Sharing jobs is called division of labour. Each kind of cell can do its one job well. So sharing jobs makes the body work better.

Try the lab to finish this lesson.