PrepTest 134, Section 3, Question 17
Science writer: The deterioration of cognitive faculties associated(72 more words not shown)
Which one of the following,(10 more words not shown)
- AThe inability of(20 more words not shown)
- BAcetylsalicylic acid reduces(8 more words not shown)
- CThe activity of(14 more words not shown)
- DThe protein BA(9 more words not shown)
- EImmune reactions by(11 more words not shown)
Reading the argument
The brain's defense could be doing damage of its own. That's the science writer's explanation of the cognitive decline associated with Alzheimer's.
Follow the sequence described here. Protein BA builds up because patients can't eliminate it. Microglia, the brain's immune cells, attack those deposits by releasing poisons. Those poisons also destroy healthy brain cells nearby. Think of a fight in which the attack on the target also damages the surrounding area: the response to a problem can create another problem.
That gives the writer a mechanism connecting microglia with declining cognitive function. The writer also points to anti-inflammatory drugs that slow the deterioration. How does that drug observation fit the proposed explanation?
What we’re looking for
I don't have a specific new fact to predict yet. For this strengthener, I want something that ties the evidence more firmly to harmful microglial activity. Keep the conclusion precise: it concerns the cause of cognitive deterioration associated with Alzheimer's, not a complete explanation of why someone initially develops the disease.
Working the answers
- A
This is tempting because it connects the protein problem to the immune system. But an unspecified deficiency that prevents removal of BA isn't the same thing as harmful activity by microglia. A tells us why the deposits might accumulate; it doesn't directly reinforce the writer's particular explanation of how microglia cause cognitive decline. Mentioning the immune system isn't enough to make every connection equally supportive.
- BCorrect
Now the drug observation fits the proposed cause. The passage says acetylsalicylic acid slows deterioration; B says it reduces production of immune cells in the brain. Microglia are those immune cells. If reducing their production accompanies slower deterioration, that supports the claim that their activity contributes to the damage. It doesn't prove the cause by itself, but it gives the drug's beneficial effect a relevant link to the writer's account.
- C
Clearing some protein deposits could be beneficial while the same immune activity also harms nearby healthy cells. Both effects could happen at once. C therefore isn't automatically a refutation of the argument, but it doesn't strengthen the claim about the harmful effect on cognitive function. It describes success against the target rather than evidence of the surrounding damage.
- D
This offers a direct harmful effect of BA itself. If the protein directly interferes with cognitive function, that supplies another route to deterioration besides the microglial attack. It does not support attributing the decline specifically to the activity of those immune cells.
- E
Microglia reacting in other brain diseases doesn't tell us what causes the deterioration discussed here. Those reactions could have different roles or consequences. We need support for this proposed mechanism in Alzheimer's-associated decline, not merely another setting in which microglia act.
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