LSAT 139 | Section 4 | Logical Reasoning: Q23

LR Question 23 Explanation

QUESTION TEXT: Botanist: In an experiment, scientists raised domesticated…

QUESTION TYPE: Strengthen

CONCLUSION: Pesticide resistance would spread from crops to their relatives that are weeds.

REASONING: Flower color spread from domestic radishes to wild radishes. Pesticide resistance is genetically engineered.

ANALYSIS: We don’t know much about the spread of genetic traits.

• Maybe flower color is easier to spread than other traits.
• Maybe traits can spread easily in radishes, but not in other plants.
• Maybe genetically engineered traits are hard to spread.

To strengthen this argument, we could prove the opposite of one of those statements.

For example, suppose traits are harder to spread in radishes than in other plants. Then the fact that the trait did spread in radishes is evidence that traits could spread in other plants too.

___________

1. It doesn’t matter how easy it is to spread a trait from a wild to a domestic. The stimulus only talks about spreading from domestic to wild.
2. This is vague. Maybe it took a 50% increase in the ratio to increase spread speed by 1%. What does that tell us? It’s not clear what effect this has on the spread of other traits.
3. If radishes are not representative, then the argument is weaker. Radishes may not prove anything about other plants.
4. Pesticide resistance is a genetically engineered trait. The argument would be stronger if flower color were genetically engineered too. That would prove that genetically engineered traits could spread. This is a weaken answer.
5. CORRECT. This shows that almost any other genetic trait could spread more easily than radish color. So this experiment is fairly strong evidence that other traits such as pesticide resistance could spread.