Cells and cellular structure. Peer inside the fine and jewelled interior of the cell. Complex and self-contained, cells are the building blocks of our bodies. They do different jobs and can look quite different from one another. There are immune cells that protect us and red blood cells that carry oxygen around our bodies. Sperm cells (spermatozoa) race to egg cells (ova). Nerve cells (brain cells or neurons) light up like Christmas trees. There is a plant cell, too. Cells can go wrong too, and cause cancer.
