A black and blue mark under the surface of the skin, caused by bleeding under the skin. The smallest blood vessels that reach into the tiniest areas of the body. A person whose body carries a gene with the information that transmits a certain characteristic, but who does not show that characteristic. A tough, elastic substance that covers and protects the bone ends in many movable joints. The smallest unit of living tissue capable of functioning independently.
All human life starts as a single cell inside the mother.
A structure made up of genes, located in each cell. A plug that develops to stop the body from bleeding. Proteins made by the body that act as a team to relay the message to make a fibrin net. There are at least 14 clotting factors, identified by roman numerals. A deficiency in one of the clotting factors causes prolonged bleeding and is known as hemophilia.