LSAT 151 – Section 4 – Question 22

LSAT 151 - Section 4 - Question 22

September 2018

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

Request new explanation

Target time: 1:27

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
PT151 S4 Q22
+LR
+Exp
Weaken +Weak
Causal Reasoning +CausR
A
2%
152
B
6%
155
C
2%
153
D
81%
164
E
9%
157
143
150
158
 +Medium 145.196 +SubsectionEasier

Biologist: When bacteria of a particular species are placed in a test tube that has different areas lit with different colors of light, the bacteria move only into the areas lit with a particular shade of red. The bacteria contain chlorophyll, a chemical that allows them to produce energy more effectively from this color of light than from any other. This suggests that the bacteria detect this color of light by monitoring how much energy their chlorophyll is producing.

Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that certain bacteria detect a particular shade of red by monitoring how much energy their chlorophyll produces. This is based on the fact that, when placed into a test tube that has different areas lit with different colors of light, the bacteria move only into areas lit with that shade of red. In addition, the bacteria’s chlorophyll allows them to produce energy more effectively from this shade of red than from any other color.

Notable Assumptions
The author assumes there’s no other explanation for why the bacteria moves only to those areas that are lit with that shade of red.

A
If the chlorophyll is removed from the bacteria, but the bacteria are otherwise unharmed, they no longer show any tendency to move into the areas lit with the particular shade of red.
This strengthens the argument by helping to establish a connection between chlorophyll and moving to that shade of red.
B
The bacteria show little tendency to move into areas containing light in colors other than the particular shade of red, even if their chlorophyll can produce some energy from light in those colors.
This is consistent with the author’s hypothesis. Because those other shades don’t produce energy as effectively, the bacteria tends not to move to those areas.
C
The areas of the test tube lit with the particular shade of red favored by the bacteria are no warmer, on average, than areas lit with other colors.
This strengthens the argument by eliminating the alternate explanation that the bacteria are moving to the areas that are warmer rather than because of the greater energy produced by their chlorophyll.
D
The bacteria show no tendency to move into areas lit with blue even when those areas are lit so brightly that the bacteria’s chlorophyll produces as much energy in those areas as it does in the red areas.
This presents evidence inconsistent with the author’s hypothesis. If the bacteria don’t move to areas lit in blue, even if those areas produce as much energy as the areas lit in the particular shade of red, this suggests the bacteria isn’t moving due to its chlorophyll’s energy.
E
There are species of bacteria that do not contain chlorophyll but do move into areas lit with particular colors when placed in a test tube lit with different colors in different places.
Other bacteria might move toward other lights for other reasons besides chlorophyll. The author never suggested that no bacteria can ever move to any lights through other methods. The conclusion is just that this particular bacteria detects the red light through chlorophyll.

Take PrepTest

Review Results

LSAT PrepTest 151 Explanations

Section 1 - Reading Comprehension

Section 2 - Logical Reasoning

Section 3 - Logical Reasoning

Section 4 - Logical Reasoning

Get full LSAT course

Leave a Reply