December 2007 LSAT
Section 4
Question 21
Based on the passage, the author would probably hold that which one of the following principles is fundamental to lon...
Replies
Alyona1983 on February 3, 2020
That is, why A and E are wrong?Ravi on February 4, 2020
@Alyona1983,Let's take a look at (A), (E), and (D).
(A) says, "The reproduction of the predator population should be
synchronized with that of the prey population, so that the number of
predators surges just prior to a surge in prey numbers."
The first part of (A) works well, but there is nothing that is implied
or made explicit about a spike in population, so this is why this
answer choice is out.
(E) says, "The predator population should be vulnerable only to
pesticides to which the prey population is also vulnerable."
The problem with (E) is that it's too specific for the author to
consider fundamental to long-term predatory control of agricultural
pests, so we can get rid of this choice.
(D) says, "The predator population’s level of consumption of the prey
species should be responsive to variations in the size of the prey
population."
If you pay attention to how this question is worded, you'll see that
it says 'fundamental,' and fundamental has a very similar meaning to
the word 'necessary.' Therefore, this question is basically asking us
which of the following answer choices, if not included, would make the
long-term control of pests a failure. Since 'fundamental' and
'necessary' essentially mean the same thing, we can actually use the
negation test for this question. If we negate (D) (if the predator's
consumption is not responsive), then the pest would prevail in the
field, which would result in a disaster. If this is the case, then the
predator would be useless. Thus, (D) is essential to the long-term
success of pest control, so it's the correct answer.
Does this help. Let us know if you have any other questions!