__ is done at 121 centigrade degree, for 15 minutes at 1 atmospheric pressure Answer: square

The process described in the question is known as autoclaving. Autoclaving is a sterilization method that uses high-pressure saturated steam to eliminate all forms of microorganisms, including large numbers of bacterial spores. The process is typically done at 121 degrees Celsius (250 degrees Fahrenheit) for 15 minutes at 1 atmospheric pressure. This method is commonly used in laboratories, hospitals, and other facilities where sterilization of equipment and media is required.