Overview Rash from poison ivy. Many people develop an itchy rash that causes lines or streaks that look like this. Poison ivy, oak and sumac: Overview Many people get a rash from poison ivy, poison oak, and poison sumac. This rash is caused by an oil found in the plants. This oil is called urushiol (you-ROO-shee-all).
Cells in heart muscle process a lot of energy, so they have a large number of mitochondrion, the part of the cells where energy is made. Like all living things, cells die. The number of cells that an adult male loses per minute is roughly 96 million.
When cells divide, they make new cells. A single cell divides to make two cells and these two cells then divide to make four cells, and so on. We call this process cell division and cell reproduction, because new cells are formed when old cells divide. The ability of cells to divide is unique for living organisms. Why Do Cells Divide?