<span>The answer is letter B.
Some bacteria that interact with humans can cause benefits to the body when they are small in numbers. An example of this bacteria is the lactobacilli which can be found as an ingredient in some drinks that can purify the digestive system. Though, they can only be taken in small amounts because they may overwhelm the immune system which can cause major complications within the internal organs. Some bacteria that interact with humans can be harmful because of their capacity to divide at a fast rate. <span>
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Traits that have 3 or more phenotypes may be the result of MULTIPLE alleles, I believe. Hope that helps!
<span>systematic knowledge of the physical or material world gained through observation and experimentation.</span>
