Extract:
Microbes and Health
There are 10 times more microbes than human cells in the human body. Scientists have long known that the human body is host to a staggering number of microorganisms, but recent information is shedding light on just how pivotal a role these bacteria play in the development of the human immune system.
The human body plays host to a wide array of microorganisms that are specially adapted to survive in particular portions of the human body. There is such a great amount of variation in these microorganisms that few people will share the same strains of bacteria in the same quantities. This process begins at birth: a newborn infant emerges from the womb, a germ-free environment, and is immediately coated with germs from its mother’s birth canal. These germs immediately begin to breed and colonize the human body that will now be its new host.
The most intriguing discovery is not that the body’s immune system tolerates these millions of harmless organisms, but that it may rely upon their presence to function properly. Scientists recently found that with laboratory mice that could not produce a particular inflammation-reducing molecule, upon being injected with a particular strain of bacteria that was then allowed to breed, their immune system quickly developed the ability to synthesize that molecule. Simply put, the mice needed the bacteria for their immune systems to function properly.
This same basic concept is also being used with humans. A relatively experimental process known as fecal bacteriotherapy is now being used to reintroduce healthy bacteria into a colon that lacks the capability to defend itself against pathogenic agents. Scientists are just beginning to understand the important role that these microorganisms play in the body of a healthy human being, but early tests have yielded remarkable discoveries.
Which of the following is not listed as a detail in the passage?
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A
Babies are born coated with germs from the birth canal.
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B
Mice and humans respond to microbes similarly.
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C
Few people share the same microbes in the same quantities.
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D
Human bodies contain far more microbes than they do cells.
The detail not listed is that mice and humans respond to microbes similarly, while both are discussed, the passage never explicitly compares their responses or states they're similar.
A) Babies are born coated with germs from the birth canal.
Explicitly stated: "a newborn infant... is immediately coated with germs from its mother's birth canal" upon emerging from the "germ-free environment" of the womb.
B) Mice and humans respond to microbes similarly.
Never stated. The passage describes mouse research showing immune dependency, then separately mentions human bacteriotherapy applications, but never draws explicit parallels between species' responses or claims similarity. This represents an unsupported inference.
C) Few people share the same microbes in the same quantities.
Explicitly stated: "There is such a great amount of variation in these microorganisms that few people will share the same strains of bacteria in the same quantities."
D) Human bodies contain far more microbes than they do cells.
Explicitly stated in the opening sentence: "There are 10 times more microbes than human cells in the human body."
Conclusion
Three details appear verbatim in the text: microbial colonization at birth, individual microbial variation, and numerical microbial dominance. The mouse-human similarity claim represents an extrapolation beyond the passage's actual content boundaries, connecting two examples without explicit comparative language.