BOSTON, Nov 13 (LSN) Scientists at Advanced Cell Technology of Worcester, Mass., announced yesterday that they had created a “master cell” by combining a human cell with a cow egg. The researchers said that the procedure would be used to grow replacement body tissues. Other experts in the field were skeptical of the claim, but did say that the incident called for laws governing such research.  According to a report by the Associated Press, the hybrid cell is made by removing the nucleus of a cow egg and inserting a human cell’s nucleus. Theoretically, the hybrid cell could be transferred to a uterus and grown into a clone of the human from whom the cell originated. However, Dr. Michael West, Advanced Cell Technology’s chief executive claims that cloning is not the objective – growing replacement body parts is the goal.