Answer:
Either due to mistakes when the DNA is copied or as the result of environmental factors such as UV light and cigarette smoke.
HIV tests are used to detect the presence of the human immunodeficiency virus
(HIV) the virus that causes acquired immunodeficiency syndrome (AIDS) in serum, saliva , or urine such tests may antibodies, antigens, or RNA .
Enzymes are considered catalysts, they help reactants and can be used over and over
