OG Test 1 - Passage IV

Questions 45-59 are based on the following passage.

Talking Bacteria

In her lab at Princeton 45University, molecular biologist, Bonnie Bassler leans over a collection of petri 46dishes; her face illuminated by an aquamarine glow. The glow, caused by a particular 47species, of bacteria is confirmation of a phenomenon Bassler has been investigating for years. Bacteria, the simplest forms of life, have the ability to communicate with each other.

As a student in graduate school, Bassler became intrigued with other 48researchers' and their discoveries involving Vibrio 49fischeri; a luminescent marine bacteria. Researchers found that these bacteria only begin to glow once they have formed a group. A series of experiments revealed that each bacterial cell releases an autoinducer, a type of chemical signal. A sensory protein 50allowed other bacteria to "hear" this molecular message. Once the bacteria have released a high enough concentration of 51autoinducer, they assemble and begin to glow. This "quorum sensing" enables the bacteria to coordinate their actions and perform their specific function.

52On the contrary, in her own lab, Bassler found evidence of quorum sensing in a 53related bacterial species called Vibrio harveyi. She also discovered that V. harveyi release a second autoinducer, or AI-2. This AI-2, which Bassler has described as a chemical "trade language," makes it possible for bacteria to communicate with other species of bacteria in the 54same neck of the woods. She found that each of the species she studied, including ones that live in humans, releases AI-2.

After her 2002 discovery, Bassler began using information from her quorum-sensing studies to understand how virulent strains of bacteria found in humans 56communicate. These 57disease-spreading bacteria rely on quorum sensing to spread disease. Bassler is hopeful that her ongoing studies of AI-2 will enable [un:58]she and her team[/n:58] to disrupt quorum sensing.59

Question 45

  • A NO CHANGE

  • B University, molecular biologist Bonnie Bassler,

  • C University, molecular biologist Bonnie Bassler

  • D University molecular biologist Bonnie Bassler

Question 46

  • F NO CHANGE

  • G dishes and her face is

  • H dishes, her face is

  • J dishes, her face

Question 47

  • A NO CHANGE

  • B species, of bacteria,

  • C species of bacteria,

  • D species of bacteria

Question 48

  • F NO CHANGE

  • G researcher's and their

  • H researchers'

  • J researchers

Question 49

  • A NO CHANGE

  • B fischeri which is

  • C fischeri,

  • D fischeri

Question 50

  • F NO CHANGE

  • G would have allowed

  • H has allowed

  • J allows

Question 51

  • A NO CHANGE

  • B autoinducer-they

  • C autoinducer. They

  • D autoinducer they

Question 52

  • F NO CHANGE

  • G Eventually,

  • H Ordinarily,

  • J Namely,

Question 53

  • A NO CHANGE

  • B related, bacterial species, called

  • C related, bacterial species called

  • D related bacterial species called,

Question 54

  • F NO CHANGE

  • G neighboring proximity.

  • H surrounding locale.

  • J vicinity.

Question 55

Which of the following alternatives to the underlined portion would NOT be acceptable?

  • A the kinds

  • B species

  • C those

  • D them

Question 56

  • F NO CHANGE

  • G has been communicating.

  • H is communicating.

  • J communicates.

Question 57

  • A NO CHANGE

  • B bacteria that Bassler has studied

  • C bacteria that live in humans

  • D bacteria

Question 58

  • F NO CHANGE

  • G her and her team

  • H herself and them

  • J her and them

Question 59

At this point, the writer is considering adding the following information: and ultimately develop new methods for treating bacterial infections Given that the information is accurate, should the writer make this addition here?

  • A Yes, because it clarifies that Bassler and her team are focusing their research on bacteria that live in humans.

  • B Yes, because it specifies how Bassler's research could directly affect humans.

  • C No, because it fails to specify which strains of bacteria are prone to attacking humans' immune systems.

  • D No, because it fails to explain how Bassler and her team plan to disrupt quorum sensing.

Questions:

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