LSAT 117 | Section 2 | Logical Reasoning: Q8

LR Question 8 Explanation

QUESTION TEXT: Most plants have developed chemical defenses against …

QUESTION TYPE: Weaken – EXCEPT

CONCLUSION: The additional threat posed by synthetic pesticides is minimal.

REASONING: Plants naturally contain many pesticides, and humans consume these natural pesticides every day without harm.

ANALYSIS: The argument relies entirely on a comparison: Natural pesticides don’t harm us, so synthetic pesticides probably don’t either.

To weaken, we want answers showing that natural and synthetic pesticides are meaningfully different. There will be four of those, since this is a Weaken – EXCEPT question.

The correct answer will be the only one that is either irrelevant or strengthens the similarities between the two.

___________

1. Weakens. If humans have been consuming natural pesticides for thousands of years, we may have adapted to them. But we may not be adapted to synthetic pesticides.
2. Also weakens. Even if natural pesticides are harmless at low concentrations, synthetic pesticides may exist at much higher concentrations.
3. Also weakens. If natural pesticides are generally less potent, then their safety doesn’t tell us much about more toxic synthetic pesticides.
4. Also weakens. If natural pesticides target only specific parasites, but synthetic pesticides harm many kinds of organisms, then synthetic pesticides may pose greater risks to humans.
5. CORRECT. This strengthens the argument. If synthetic pesticides usually have chemical structures similar to natural pesticides, then the comparison between them becomes stronger. Similar chemical structures suggest that the substances may behave similarly.