- The biggest cells in the body can be nerve cells. Although the main nucleus of nerve cells is microscopic the tails can extend for over 3 ft. (1 m) or more through and be seen even without a microscopic.
- Among the smallest cells in the body are red blood cells. These are just 0,0075 mm across and have no nucleus since nearly their only task is ferrying oxygen.
- Most body cells live a very short time and are continually being replaced by new ones. The main exception are nerve cells these are long lived but rarely replaced.