LSAT 148 – Section 4 – Question 07

LSAT 148 - Section 4 - Question 07

December 2016

You need a full course to see this video. Enroll now and get started in less than a minute.

Ask a tutor

Target time: 1:08

This is question data from the 7Sage LSAT Scorer. You can score your LSATs, track your results, and analyze your performance with pretty charts and vital statistics - all with a Free Account ← sign up in less than 10 seconds

Question
QuickView		 Type Tags Answer
Choices		 Curve Question
Difficulty		 Psg/Game/S
Difficulty		 Explanation
PT148 S4 Q07
+LR
Strengthen +Streng
Causal Reasoning +CausR
A
4%
160
B
84%
163
C
4%
158
D
2%
154
E
7%
160
124
139
153
 +Easier 147.694 +SubsectionMedium

Although some animals exhibit a mild skin reaction to urushiol, an oil produced by plants such as poison oak and poison ivy, it appears that only humans develop painful rashes from touching it. In fact, wood rats even use branches from the poison oak plant to build their nests. Therefore, urushiol probably did not evolve in these plants as a chemical defense.

Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that urushiol (the chemical that causes poison ivy and poison oak reactions) did not evolve as a chemical defense for these plants. This is based on the observation that, while some animals have a mild urushiol reaction, the reaction is not severe in any animals other than humans. Furthermore, wood rats use urushiol-producing plants for nest material.

Notable Assumptions
The author also assumes that the mild skin reactions caused by urushiol don’t deter animals. The author also assumes that urushiol could not have originally evolved as a chemical defense in the plants that produce it, even if it’s no longer effective.

A
Wood rats build their nests using dead, brittle branches, not live ones.
This is irrelevant, since it does not provide any additional information about the effects of urushiol and whether it likely evolved as a chemical defense. For one thing, we don’t know if live or dead branches have different urushiol content.
B
A number of different animals use poison oak and poison ivy as food sources.
This strengthens the hypothesis, since it affirms the author’s assumption that any mild reaction caused by urushiol doesn’t deter animals from using it.
C
It is common for plants to defend themselves by producing chemical substances.
This is irrelevant, since the argument only makes claims about urushiol based on observations specific to urushiol; whether chemical defenses are common in other plants doesn’t matter.
D
In approximately 85 percent of the human population, very small amounts of urushiol can cause a rash.
This is irrelevant, since the argument has already established that urushiol is harmful to humans. We primarily care about how it affects animals.
E
Poison oak and poison ivy grow particularly well in places where humans have altered natural forest ecosystems.
The growth of urushiol-producing plants in human-altered ecosystems is irrelevant to the hypothesis that urushiol did not evolve as a chemical defense in those plants.

Take PrepTest

Review Results

LSAT PrepTest 148 Explanations

Section 1 - Logical Reasoning

Section 2 - Reading Comprehension

Section 3 - Logical Reasoning

Section 4 - Logical Reasoning

Get full LSAT course

Leave a Reply