For this to happen the DNA must replicate itself exactly. When DNA replicates itself and the cell divides both of the new cells that are produced contain the exact same DNA (barring mutations) which means both new cells can code to make the same proteins.
Americium was first produced in 1944 by the group of Glenn T. Seaborg at the University of California, Berkeley. Although it is the third element in the transuranic series, it was discovered fourth, after the heavier curium.
Dr. Glenn Seaborg and Edwin McMillan, Joseph Kennedy, and Arthur Wahl are credited with the discovery of plutionium. Plutonium was chemically identified in February in 1941 by Glenn T. Seaborg, Edwin M. McMillan, Joseph W. Kennedy, and Arthur C. Wahl at the Berkeley Laboratory of the University of California (United States). They synthesized and isolated it in December of 1940 after bombarding uranium with deuterons.