According to the American Cancer Society, skin cancer is the most common type of cancer in the United States. Skin cancer is an abnormal growth of skin cells. It generally develops in areas that are exposed to the sun, but it can form in places that donât normally receive sun exposure.
Harmful bacteria: 1  E. Coli can also be harmful if food or water is contaminated with it and then eaten. 2  Listeriosis can cause individuals to become very ill and can even be potentially deadly. 3  Examples of where it can be found are in shellfish, cold cuts, and unpasteurized milk.Answer #1). Helpful bacteria: 1  E. Coli are found in the intestines of humans and aid in digestion. 2  Streptomyces is used in making antibiotics. 3  Rhizobium are helpful bacteria found in the soil.
There are many kinds of bacteria, some which cause deadly diseases and some which are helpful to man. Those which are harmful cause diseases in man, animals, and plants. They can cause food to spoil, even poisoning people who eat them. But there are a great many bacteria that man and nature use in helpful ways. For example, bacteria play an important role in making buttermilk, sauerkraut, cheese, and vinegar by causing a chemical change called fermentation. Bacteria also attack dead plants and animals, and break them down into nourishment for the soil. Bacteria are even used to purify water in sewer treatment plants!