PrepTest 124, Section 3, Question 20
The ability of mammals to control their internal(52 more words not shown)
Which one of the following(8 more words not shown)
- AOrganisms unable to(19 more words not shown)
- BMammals are the(12 more words not shown)
- CThe brain cannot(13 more words not shown)
- DThe development of(19 more words not shown)
- EOrganisms incapable of(11 more words not shown)
Reading the argument
Does controlling body temperature explain the development of intelligence, or does it just keep chemical reactions at suitable temperatures?
The author connects those ideas. Mammals can control internal temperature; that lets them ensure the brain's chemical reactions occur at proper temperatures; therefore that ability is a factor in the development of their brains and intelligence.
My first concern is whether internal control is needed. What if an animal's surroundings already keep its brain at a suitable temperature? In that situation, the reactions could occur properly even without the animal controlling its temperature. That's a possible alternative, not a fact about a particular species.
What we’re looking for
But be careful with the conclusion: the author says temperature control is a factor, not the only possible route to intelligence. For the necessary-assumption question, we shouldn't demand a claim that no intelligence could ever exist without it. We need something connecting the temperature-related evidence to the development of intelligence. Let's check which answer the reasoning truly requires.
Working the answers
- A
How an organism generates heat isn't the missing connection to intelligence. It could generate some internal heat without being able to regulate its temperature. The argument doesn't need to rule that out; it needs temperature control to matter for the brain and intelligence.
- B
Mammals needn't be the only animals with this ability. Other animals could also regulate their temperatures without undermining the claim that the ability played a role in mammals' development. B adds exclusivity the argument doesn't require.
- C
This would rule out intelligence whenever brain reactions are subject to uncontrolled temperatures. That's stronger than saying control contributes to the development of intelligence. The author could think temperature control helps while still allowing intelligence in an organism whose temperatures aren't internally controlled. As we wondered earlier, uncontrolled temperatures could still happen to be suitable.
- DCorrect
“Not independent of” means there is a connection. The development of mammalian intelligence must have something to do with those brain reactions occurring at proper temperatures. Otherwise, why would evidence about keeping reactions at the proper temperatures support the conclusion about intelligence?
This supplies the needed link without the extreme claim in C. It doesn't say every intelligent organism must regulate its temperature, and it doesn't merely repeat the conclusion. It connects the proposed benefit of temperature control to the development the author wants to explain.
- E
Lack of temperature control doesn't necessarily make chemical processes unpredictable. Conditions might be stable or their changes predictable without the organism controlling them. More importantly, the argument doesn't require every organism lacking control to have unpredictable processes. That claim doesn't supply the needed connection to intelligence.
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