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.
In nature, oxygen is released from plants and sea plankton during photosynthesis. Oxygen floats upward into the atmosphere and in turn is converted into ozone by ultraviolet radiation. This blocks out the harmful UV b rays that cause skin cancer. The production of ozone is dependent on the amount of the sunâs energy.