Description:
The cell is the basic unit, or building block, of all life. In humans, a typical cell will have a central nucleus, which controls the cell, and will be filled with a jelly-like substance called cytoplasm. Human cells also contain mitochondria, which generate energy for the cell, and a membrane, which encloses all of the cell's contents. Different cells are specialised to fulfil different functions; red blood cells are designed to carry oxygen around the body, whereas brain cells are designed to send information to each other.