The ability of mammals to control their internal body temperatures is

Question

The ability of mammals to control their internal body temperatures is a factor in the development of their brains and intelligence.This can be seen from the following facts: the brain is a chemical machine, all chemical reactions are temperature dependent, and any organism that can control its body temperature can assure that these reactions occur at the proper temperatures.

Which one of the following is an assumption on which the argument depends?

(A) Organisms unable to control their body temperatures do not have the capacity to generate internal body heat without relying on external factors.

(B) Mammals are the only animals that have the ability to control their internal body temperatures.

(C) The brain cannot support intelligence if the chemical reactions within it are subject to uncontrolled temperatures.

(D) The development of intelligence in mammals is not independent of the chemical reactions in their brains taking place at the proper temperatures.

(E) Organisms incapable of controlling their internal body temperatures are subject to unpredictable chemical processes.

Tan2017 · Answer

The brain is a chemical machine, all chemical reactions are  temperature dependent,  and any organism that can control its body temperature can assure that these reactions occur at the proper temperatures.

The ability of mammals to control their internal body temperatures is a factor in the development of their brains and intelligence.

Assumption- The development of intelligence in mammals is not independent of the chemical reactions in their brains taking place at the proper temperatures.

abhimahna · Answer

The argument is saying Controlling body temperature and Development of brains and intelligence are linked with each other.

So, assumption is they are not happening independently.

That is what option D is doing.

(A) Organisms unable to control their body temperatures do not have the capacity to generate internal body heat without relying on external factors.  : OFS. We are no where telling anything we need. 
(B) Mammals are the  only  animals that have the ability to control their internal body temperatures.  Extreme .
(C) The brain cannot support intelligence if the chemical reactions within it are subject to uncontrolled temperatures.  : We know it supports at controlled temperatures but we are not sure what would otherwise. So, incorrect 
(D) The development of intelligence in mammals is not independent of the chemical reactions in their brains taking place at the proper temperatures.  Correct for the reasons stated above. 
(E) Organisms incapable of controlling their internal body temperatures are subject to unpredictable chemical processes.  : What would happen if they do not control is OFS.

Nightmare007 · Answer

D is my go. We must state that intelligence or development is dependent on chemical reactions.

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nazgull · Answer

Only negating option D tears up the argument apart. Hence it is the best choice.

chesstitans · Answer

although this is a LSAT question, the pattern is very similar to that of a gmat question.
D is the answer b/c D fulfills the gap between "Development of intelligence" and "the brain"; also, C does not concern with "dependent"
The pattern in A,B,C,E is that the scope has shifted; in other words, the argument does not concern with what is not stated.

nightblade354 · Answer

Bumping for discussion. This is a tremendous LSAT assumption question!

lybeaver · Answer

Premise:  (1) Ability to control body temperature - develop brain
Why? (2) Chemical reaction in brain depends on temperature. Controlling temperature assure reaction occur at proper temperature.

Here, the missing gap (assumption) is that reaction occur at proper temperature could lead to the development of brain. In other words, the development of brain depends on chemical reaction at proper temperature. We must link (1) to (2)

(A) Organisms unable to control their body temperatures do not have the capacity to generate internal body heat without relying on external factors.  
Wrong. The argument only concerns about organism that can control body temperature while A talks about organism who are  UNABLE  to control body temperature. In addition, external factors is irrelevant to scope.

(B) Mammals are the only animals that have the ability to control their internal body temperatures.  
Wrong. Whether mammals are the  only animals who can control body temperature  or not is irrelevant.

(C) The brain cannot support intelligence if the chemical reactions within it are subject to uncontrolled temperatures.  
Wrong. TRAP. The missing gap is that reaction occur at proper temperature could lead to the development of brain, we don't know what would otherwise

(D) The development of intelligence in mammals is not independent of the chemical reactions in their brains taking place at the proper temperatures.  
Correct. The development of intelligence in mammals is not independent of the chemical reactions in their brains taking place at the proper temperatures = The development of intelligence in mammals depends on the chemical reactions in their brains taking place at the proper temperatures.

(E) Organisms incapable of controlling their internal body temperatures are subject to unpredictable chemical processes. 
Wrong. Whether  chemical processes are unpredictable  or not is irrelevant

unraveled · Answer

The ability of mammals to control their internal body temperatures is a factor in the development of their brains and intelligence.This can be seen from the following facts: the brain is a chemical machine, all chemical reactions are temperature dependent, and any organism that can control its body temperature can assure that these reactions occur at the proper temperatures.

Which one of the following is an assumption on which the argument depends?

(A) Organisms  unable to control their body temperatures  do not have the capacity to generate internal body heat without relying on external factors. - WORNG. This one is like E only. Beyond scope.

(B)  Mammals are the only animals that have the ability to control  their internal body temperatures. - WRONG. Not a relevant assumption. Infact it does nothing to the passage.

(C) The  brain cannot support intelligence if  the chemical reactions within it are  subject to uncontrolled temperatures . - WRONG. Reversal case that may or may not be true.

(D) The development of intelligence in mammals  is not independent  of the chemical reactions in their brains taking place at the proper temperatures. - CORRECT. Only if dependent than it can happen.

(E) Organisms  incapable of controlling their internal body temperatures  are subject to unpredictable chemical processes. - WRONG. Those who can't control is not in the scope of the passage. Like A only.

Answer D.

VerbalBot · Answer

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The ability of mammals to control their internal body temperatures is

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