The primary concern of cell division is the maintenance of the original cell's genome. Before division can occur, the genomic information that is stored in chromosomes must be replicated, and the duplicated genome must be separated cleanly between cells. A great deal of cellular infrastructure is involved in keeping genomic information consistent between generations.
Military discharge certificate. In the United States of America, every service member who is discharged or released from active duty is issued a DD Form 214, a military discharge certificate. A reservist who is called up to active duty is given a DD 214 when he or she is deactivated and returned to the reserves.
It is just another name for military job. In the Marine Corps, the MOS is a four digit number that represents the kind of job you are assigned. The first two digits are the category of your job, and the last two digits are the specific job title. So for a MOS of 0331, the 03 means that you are Infantry, and the 31 means you are a machine gunner.