LSAT 126 - Section 1 - Question 20

April 21, 2012

A study of rabbits in the 1940s convinced many biologists that parthenogenesis—reproduction without fertilization of an egg—sometimes occurs in mammals. However, the study’s methods have since been shown to be flawed, and no other studies have succeeded in demonstrating mammalian parthenogenesis. Thus, since parthenogenesis is known to occur in a wide variety of nonmammalian vertebrates, there must be something about mammalian chromosomes that precludes the possibility of parthenogenesis.

A
takes for granted that something that has not been proven to be true is for that reason shown to be false
The author assumes that because parthenogenesis has not been proven to occur in mammals, that it does not occur in mammals. This is flawed because it’s possible parthenogenesis. does occur in mammals, even if it hasn’t yet been proven.
B
infers that a characteristic is shared by all nonmammalian vertebrate species merely because it is shared by some nonmammalian vertebrate species
The author states that parthenogenesis is known to occur in a “wide variety” of nonmammal vertebrates. That doesn’t mean the author believes parthenogenesis ocurs in “all” nonmammalian vertebrates.
C
rules out an explanation of a phenomenon merely on the grounds that there is another explanation that can account for the phenomenon
The author doesn’t point to an alternate explanation of parthenogenesis. Also, the issue is whether parthenogenesis occurs in mammals, not what explains the phenomenon of parthenogenesis.
D
confuses a necessary condition for parthenogenesis with a sufficient condition for it
There are no necessary or sufficient conditions for parthenogenesis described in the premises or the conclusion. So there cannot be a confusion of a necessary condition for parthenogenesis with a sufficient condition.
E
assumes that the methods used in a study of one mammalian species were flawed merely because the study’s findings cannot be generalized to all other mammalian species
The claim that the study’s methods were flawed is a premise. We don’t know why the author believes the study’s methods were flawed, so we cannot say the author assumed anything regarding why the studies were flawed.

16 comments

LSAT 126 - Section 1 - Question 21

April 21, 2012

Really tough question. Reading only the question stem, it's not clear what type of question it is. Some general "principle" type, I suppose. So, you read the stimulus and then glance at the answers again. Notice there's an argument in the stimulus. Notice the answers are all conditionals. We're looking for a PSA answer choice. We can get away with fudging some ideas because the question stem has the word "most" in it.

So let's lay the argument out.

Sentence 1 zooms into the subset of "Most TV shows". What about them? They depend on advertising funding.
show alive --> funding
contrapositive
/funding --> /show alive (think canceled show)

Sentence 2 tells us a necessary condition of advertising funding.
funding --> many people buy product

Now we get to chain up:
show alive --> funding --> many people buy product

Sentence 3 runs the contrapositive on the whole chain.
/many people buy product --> /funding --> /show alive

[I think we really could have done without sentence 3 since it's not adding anything new. We could have chained up sentences 1 and 2 on our own and also ran the contrapositive on our own. Sentence 3 feels redundant to me.]

Now, sentence 4, the conclusion.
feel show worth preserving --> buy product

All together now:

[P] show alive --> funding --> many people buy product
__________________
[C] feel show worth preserving --> buy product

What's our most standard, cookie cutter formulation of a PSA or SA answer choice that we are trained to anticipate and look for?
IF P, THEN C

With some cleverly crafted referential phrasing, that's precisely what (B) is saying:

IF [a TV show would be canceled unless many people took certain actions], THEN [everyone who feels that the show is worth preserving out to take those actions]. IF [P], THEN [C]

Try to figure it out before reading on.

IF [P], THEN [C]
[P] is [a TV show would be canceled unless many people took certain actions]
[C] is [everyone who feels that the show is worth preserving out to take those actions]

[P] first. "unless" is group 3, negate sufficient. "not a TV show would be canceled --> many people took certain actions" =
"show alive --> many people took certain actions"
What could those actions possibly be referring to? Buy product.
"show alive --> many people buy product"

Now [C]. "everyone" is group 1, sufficient. "feel show worth preserving --> take those actions" Again, what could those actions possibly be referring to? Again, buy product.
"feel show worth preserving --> buy product"

The problem with answer choice (A) is that it's not describing the same shows that the stimulus is describing. The shows in the stimulus depended for their survival on MANY people buying a product. This conforms to our common sense expectations of TV shows. I would expect that the real life TV shows that depend on advertising funding would depend for their survival on MANY people buying whatever products they're meant to be buying.

(A) however talks about a set of TV shows whose survival depends on ONE single person buying a product. "would be canceled unless one took certain actions" What show in the world's survival is dependent on a single person taking some action? I have no idea. But whatever the TV shows (A)'s talking about, they're not the same TV shows that the stimulus talked about.


44 comments

LSAT 126 - Section 1 - Question 22

April 21, 2012

Psychologist: It is well known that becoming angry often induces temporary incidents of high blood pressure. A recent study further showed, however, that people who are easily angered are significantly more likely to have permanently high blood pressure than are people who have more tranquil personalities. Coupled with the long-established fact that those with permanently high blood pressure are especially likely to have heart disease, the recent findings indicate that heart disease can result from psychological factors.

Summarize Argument: Phenomenon-Hypothesis
The author hypothesizes that psychological factors can cause heart disease. This is based on a study showing that people who are easily angered are more likely to have permanently high blood pressure than people with more calm personalities, and the fact that people with permanently high blood pressure are likely to have heart disease.

Notable Assumptions
The author assumes that the correlation between being easily angered and likelihood of having permanently high blood pressure is due to anger causing the permanently high blood pressure or due to calmness causing lower blood pressure. This overlooks the possibility that high blood pressure could make one easy to anger, or that there’s an alternate cause that leads to both anger and high blood pressure. The author also assumes that high blood pressure causes heart disease.

A
Those who are easily angered are less likely to recover fully from episodes of heart disease than are other people.
This relates to the relationship between anger and recovery from heart disease. But it doesn’t undermine a causal connection between anger and the initial presence of heart disease.
B
Medication designed to control high blood pressure can greatly affect the moods of those who use it.
Without knowing whether many people take this medication, or whether the effect on moods includes making one easily angered, (B) doesn’t do enough to suggest a reversed causal relationship between being easily angered and permanently high blood pressure.
C
People with permanently high blood pressure who have tranquil personalities virtually never develop heart disease.
If anything, this could support the author’s hypothesis by showing that, despite permanently high blood pressure, calm personalities almost never get heart disease. This suggests that psychological factors may have a role to play in causing or inhibiting heart disease..
D
Those who discover that they have heart disease tend to become more easily frustrated by small difficulties.
Becoming more easily frustrated by small difficulties does not constitute being “easily angered.” So, (D) doesn’t suggest that the causal relationship between heart disease and being easily angered is reversed.
E
The physiological factors that cause permanently high blood pressure generally make people quick to anger.
This provides an alternate causal explanation for the correlation between being easily angered and having perm. high blood pressure. If certain bodily factors lead to both, there doesn’t have to be a causal relationship between being easily angered and perm. high blood pressure.

94 comments

LSAT 126 - Section 1 - Question 23

April 21, 2012

A professor of business placed a case-study assignment for her class on her university’s computer network. She later found out that instead of reading the assignment on the computer screen, 50 out of the 70 students printed it out on paper. Thus, it is not the case that books delivered via computer will make printed books obsolete.

Summarize Argument
The availability of online books won't make printed versions unnecessary. This is demonstrated by the fact that in a class, most students chose to print an assignment sheet instead of reading it online, where it was originally made available.

Notable Assumptions
The author makes a conclusion about books from premises about an assignment—in other words, the author assumes that there are enough similarities between books and assignments to draw a conclusion. A good answer choice will help bridge this gap. Additionally, the author assumes that the observed occurrence in an academic setting is generalizable.

A
Several colleagues of the professor have found that, in their non-business courses, several of their students behave similarly in relation to assignments placed on the computer network.
While this answer choice strengthens the evidence, it fails to support the relationship between the premise and conclusion (i.e., the argument). The author makes a jump from a premise about an assignment to a conclusion about books—this doesn’t fill that gap.
B
Studies consistently show that most computer users will print reading material that is more than a few pages in length rather than read it on the computer screen.
This strengthens the argument by substantiating the author’s assumption that students will print out books in addition to assignments. (B) says after a certain length people will print the reading material, strengthening the relationship between the premise and conclusion.
C
Some people get impaired vision from long periods of reading printed matter on computer screens, even if they use high quality computer screens.
This does not affect the argument. The word “some” could mean just one or two people—one person having vision issues due to computer screens doesn’t affect our argument at all.
D
Scanning technology is very poor, causing books delivered via computer to be full of errors unless editors carefully read the scanned versions.
This does not affect the argument. While it may be true that online books would be full of errors if they are not carefully read through, there is no reason for us to believe that they aren’t carefully read through every time.
E
Books on cassette tape have only a small fraction of the sales of printed versions of the same books, though sales of videos of books that have been turned into movies remain strong.
This does not affect the argument. The relative popularity between books on cassette tape and their printed version tells us nothing about the relationship between books delivered via computer and their printed versions.

23 comments

LSAT 126 - Section 1 - Question 24

April 21, 2012

Advertisement: Researchers studied a group of people trying to lose weight and discovered that those in the group who lost the most weight got more calories from protein than from carbohydrates and ate their biggest meal early in the day. So anyone who follows our diet, which provides more calories from protein than from anything else and which requires that breakfast be the biggest meal of the day, is sure to lose weight.

A
eating foods that derive a majority of their calories from carbohydrates tends to make one feel fuller than does eating foods that derive a majority of their calories from protein
The diet described involved a majority of calories from protein rather than from carbs. Whether a different kind of diet helps people “feel fuller” has no clear impact on whether the ad’s diet will help people lose weight.
B
a few of the people in the group studied who lost significant amounts of weight got nearly all of their calories from carbohydrates and ate their biggest meal at night
We know the group who “lost the most weight” got more calories from protein than from carbs. That doesn’t exclude the possibility that some people with a different diet also lost a lot of weight. They just didn’t lose the most weight.
C
the people in the group studied who increased their activity levels lost more weight, on average, than those who did not, regardless of whether they got more calories from protein or from carbohydrates
(C) suggests that exercise is another factor in weight loss. The author never assumed otherwise. The ad is merely arguing that following the ad’s diet will cause weight loss. Whether exercise also leads to weight loss doesn’t affect whether the diet leads to weight loss.
D
some people in the group studied lost no weight yet got more calories from protein than from carbohydrates and ate their biggest meal early in the day
If this possibility is true, that means not everyone on the high-protein + big meal early diet lost weight. This shows why we can’t conclude that “anyone” on the ad’s diet will “be sure to” lose weight.
E
people who eat their biggest meal at night tend to snack more during the day and so tend to take in more total calories than do people who eat their biggest meal earlier in the day
(E) describes people on a different kind of diet that isn’t what the ad describes. What’s true about those people has no affect on what will happen to people following the ad’s diet.

39 comments

LSAT 126 - Section 1 - Question 25

April 21, 2012

Some twentieth-century art is great art. All great art involves original ideas, and any art that is not influential cannot be great art.

Summary
The stimulus can be diagrammed as follows:

Notable Valid Inferences
Some 20th century art involves original ideas.

Some 20th century art is influential.

Some art that involves original ideas is influential.

If art is great, then it is original and influential.

A
Some influential art involves original ideas.
This must be true. As shown in the diagram, we can infer that some influential art involves original ideas.
B
Some twentieth-century art involves original ideas.
This must be true. As shown in the diagram, we can infer that some twentieth century art involves original ideas.
C
Only art that involves original ideas is influential.
This could be false. (C) can be diagrammed to say influential→ original. This is not a conditional claim given in the stimulus.
D
Only art that is influential and involves original ideas is great art.
This must be true. As shown in the diagram, all great art is influential and original.
E
Some twentieth-century art is influential and involves original ideas.
This must be true. As shown in the diagram, there must be at least some overlap between art involving original ideas and influential art.

12 comments

LSAT 55 - Section 1 - Question 01

April 21, 2012

3 comments

LSAT 55 - Section 1 - Question 02

April 21, 2012

3 comments

LSAT 55 - Section 1 - Question 03

April 21, 2012

3 comments

LSAT 55 - Section 1 - Question 04

April 21, 2012

14 comments

«‹207208209210211212213214215216217218219220221222223224225226227›»