ANTIBIOTIC SUSCEPTIBILITY TESTING. Bacteria demonstrate two kinds of resistance to antibiotics, namely intrinsic resistance and acquired resistance. Intrinsic resistance means that the species was resistant to an antibiotic even before its introduction.
Radiation is naturally present in our environment, as it has been since before the birth of this planet. In addition, radiation can be produced artificially, as in medical x-rays and microwaves for cooking. Nonetheless, most people are not aware of all the natural and man-made sources of radiation in our environment.
Quick Answer. Most chlorofluorocarbons are released into the atmosphere through leakages from refrigerants and the use of aerosols. They have no notable natural sources. Chlorofluorocarbons are chemical compounds composed of carbon, fluorine and chlorine. Continue Reading.