Cell signaling can be classified to be mechanical and biochemical based on the type of the signal. 1  Mechanical signals are the forces exerted on the cell and the forces produced by the cell. These forces can both be sensed and responded by the cells. Biochemical signals are the biochemical molecules such as proteins, lipids, ions and gases.
1 You must be an American citizen at least 18 years of age (or 21 years in some states). 2  You must be able to pass a drug test and in some cases, a physical endurance exam. 3  Bailiffs are expected to have clean criminal records and be model citizens [source: CV Tips ].
Requirements to Becoming a Notary Public. 1  You must be a citizen of the United States or an alien lawfully admitted for permanent residence. 2  You must be a resident or employed in the State of Illinois for at least 30 days. 3  You must be at least 18 years of age.  You must be able to read and write the English language.