In most multicellular organisms, every cell carries the same DNA, but this genetic information is used in varying ways by different types of cells. In other words, what a cell does within an organism dictates which of its genes are expressed.
Most enlisted positions require four years of active duty. If you join the Navy through an officer program, you must serve at least four of your eight years on active duty. However, pilots and flight officers must serve a minimum of eight to 10 years of active duty. Dentists, Medical Service Corps officers and nurses must serve a minimum of three years of active duty.
You must have served at least 181 days of continuous active duty and been discharged under other than dishonorable conditions. If you served less than 181 days, you may be eligible if discharged for a service connected disability. Service after 9/7/1980 (enlisted) or 10/16/1981 (officer)