BAIER: Now, does Secretary Clinton factor into this? SCHWEIZER: For that deal to go through, it needs federal government approval and one of those people that has to approve that deal is Secretary of State Hillary Clinton.
An antigen is any foreign substance which invades the body of an organism, while a pathogen is a living antigen (such as viruses or bacteria) which invade an organism. Many different kinds of white blood cells exist which are able to help the body fight foreign invaders in various ways.
Organelles called mitochondria, for example, provide energy to the cell, and organelles called vacuoles store substances in the cell. Organelles allow eukaryotic cells to carry out more functions than prokaryotic cells can. This allows eukaryotic cells to have greater cell specificity than prokaryotic cells.