Every living thing -- from a tiny bacterium to a giant whale -- contains DNA. DNA is a molecule that carries the instructions for building and running an organism. On May 21, 2010, a team of scientists led by Craig Venter announced something extraordinary: they had created a living cell using DNA that was entirely designed on a computer and assembled in a laboratory. The process took fifteen years and cost approximately $40 million. First, the team chose a simple bacterium called Mycoplasma mycoides. They decoded its DNA, which contains about one million genetic letters. Then they rebuilt that DNA from scratch using chemical building blocks. Finally, they inserted the synthetic DNA into an empty cell from a related species. The cell came to life. It grew, divided, and produced copies of itself -- all following the instructions written by humans. This achievement was both exciting and controversial. Some scientists celebrated it as a major step toward designing organisms that could produce medicines, create biofuels, or clean up pollution. Others worried about safety. If humans can create life, what happens if a synthetic organism escapes the lab? These questions are part of a field called bioethics -- the study of what is right and wrong in biology and medicine. The synthetic cell was not entirely new life. The scientists copied an existing organism's DNA rather than inventing something entirely original. But it proved that human-made DNA could control a living cell, opening a door that science had never opened before.