#15 - Main Point

[Administrator]

Complete Question Explanation

(See the complete passage discussion here: lsat/viewtopic.php?t=14646)

Main Point. The correct answer choice is (B)

With Main Point questions we should always try to prephrase an answer before looking at the
choices provided. In this case, the main point of this passage is to introduce the reader to the important
scientific discovery of NGF, as well as the steps taken by the scientist in confirming early hypotheses,
and further details about NGF uncovered through subsequent research.

Answer choice (A): The first half of this answer choice looks good, but the importance of the scientist’s
discovery was not to simply increase our understanding of chick embryos. Since the ramifications of
Rita’s discovery were further-reaching, this choice is wrong.

Answer choice (B): This is the correct answer choice. Most importantly, this response concludes that
the discovery of NGF was pivotal to biochemistry, a fact reflected in the first paragraph.

Answer choice (C): This answer choice is relevant only to the second paragraph. Since the question asks
for the main point of the passage, this answer should be eliminated. Furthermore, the passage states that
Levi-Montalcini used the tissue-culture technique, not that she devised it.

Answer choice (D): This response confines its observations to the last paragraph, and does not reflect
the main point of the passage. Furthermore, the passage actually stated that NGF is produced by tissues
to which the nerve cells will connect, and this choice contrarily claims that NGF is produced only when
nerve cells have already connected.

Answer choice (E): Once again, this response should be immediately eliminated simply because it is
relevant only to the last paragraph. Furthermore, this choice is false given the passage, because it leaves
out the possibility that nerve cells die if NGF is simply removed.

[lsatprep1215]

Hi, I want to ask about answer E, why is " it leaves out the possibility that nerve cells die if NGF is simply removed" incorrect? From line 48-55 it states that NGF is necessary for cells to continue survive and they die if they encounter anti NGF.

[Jeremy Press]

Hi lsatprep1215,

Answer choice E sets up an encounter with anti-NGF antibodies as the sole exception to the rule that NGF directs the growth of nerve cells and ensures nerve-cell survival. But in line 58 the passage states that there is another circumstance where NGF might not perform those functions: "if the factor is not present." This means that there might be some instances in animals when NGF is removed for some reason, or when NGF was not present to begin with, when it's not performing the functions identified in answer choice E. So answer choice E is too strongly worded.

To be factually aligned with the passage, answer choice E should have read: "NGF, a chemical that was discovered by Levi-Montalcini, directs the growth of nerve cells toward the cells with which they must connect and ensures the survival of those nerve cells throughout the life of the organism except when the organism produces anti-NGF antibodies or when NGF is not present for another reason."

Note that even if answer choice E were changed as I suggested above, it would still not be broad enough to be the main point of the passage.

I hope this helps!

Jeremy