LSAT Explanation PT 44, S2, Q8: Most plants have developed chemical defenses

LSAT Question Stem

Each of the following, if true, weakens the argument EXCEPT: 

Logical Reasoning Question Type

This is a Weaken question. 

Correct Answer

The correct answer to this question is E. 

LSAT Question Complete Explanation

The question type for this problem is Weaken, and it's asking us to identify the answer choice that does NOT weaken the argument presented in the passage.

The argument in the passage can be broken down as follows:

Premise: Most plants have developed chemical defenses against parasites, and humans ingest these natural pesticides without harm every day.

Conclusion: Therefore, the additional threat posed by synthetic pesticides sprayed on crop plants by humans is minimal.

The argument's structure is flawed because it assumes that natural and synthetic pesticides have the same effects on humans without providing any evidence to support this claim. To answer the question, we need to evaluate each answer choice and determine which one does not weaken the argument.

An "Evaluate" question for this argument could be "Are synthetic pesticides similar in structure and effect to natural pesticides?"

Now, let's discuss each answer choice:

a) This answer choice weakens the argument by pointing out that humans have had time to adapt to natural pesticides, suggesting that synthetic pesticides might pose a different level of threat. This is not the correct answer.

b) This answer choice also weakens the argument by stating that the concentrations of synthetic pesticides are typically higher than those of natural pesticides. This implies that synthetic pesticides could be more harmful. This is not the correct answer.

c) This answer choice weakens the argument by suggesting that synthetic pesticides are more potent than natural pesticides, which could make them more dangerous. This is not the correct answer.

d) This answer choice weakens the argument by stating that synthetic pesticides are harmful to a wider variety of organisms, increasing the likelihood that humans might be affected. This is not the correct answer.

e) This is the correct answer choice, as it does not weaken the argument. If synthetic pesticides have similar chemical structures to natural pesticides, it supports the idea that they might have similar effects on humans and thus pose a minimal additional threat.

In conclusion, the correct answer to this Weaken question is answer choice (e), as it does not undermine the argument's conclusion or the relationship between the premises and the conclusion.