They combine to form low altitude ozone
A mutation is a change in trait. For example people who are lactose intolerant are normal, but people that can can drink milk without a problem have mutated. Hopefully this makes sense and helped.
ANSWER FOR QUESTION 1:
The most common type of E. coli infection that causes illness in people is called E. coli O157, which produces a toxin known as Shiga-toxin. Shiga-toxin producing E. coli is abbreviated as STEC. Symptoms of infection with this germ include watery or bloody diarrhea, fever, abdominal cramps, nausea, and vomiting.
ANSWER FOR QUESTION 2:
Some other germs don’t cause as many illnesses, but when they do, the illnesses are more likely to lead to hospitalization. Those germs include: Anyone can get sick from eating contaminated food. Follow four simple food safety steps —clean, separate, cook, and chill—to lower your chance of food poisoning and to protect yourself and your loved ones.