#11 - Sharks have a higher ratio of cartilage mass to body

[Administrator]

Complete Question Explanation

Cannot Be True. The correct answer choice is (A)

As with most Cannot Be True questions, the stimulus does not contain
an argument. Instead, a fact pattern is presented and you are tested on
your knowledge of those facts. Let’s review each statement, sentenceby-
sentence, keeping in mind that in Cannot questions you accept the
statements in the stimulus as true:

          Statement: Sharks have a higher ratio of cartilage mass to body
          mass than any other organism.

     This is a very broad, global statement indicating that no other
     organism has a higher ratio of cartilage mass to body mass than
     sharks.

          Statement: They [sharks] also have a greater resistance to cancer
          than any other organism.

     This is another very broad, global statement indicating that no
     other organism has a greater resistance to cancer than sharks.

          Statement: Shark cartilage contains a substance that inhibits tumor
          growth by stopping the development of a new blood
          network.

This statement is narrower, and focuses only on shark cartilage.
Since no information is given about the cartilage of other
organisms, it is possible that other organisms contain the tumorinhibiting
substance mentioned in this statement.

          Statement: In the past 20 years, none of the responses among
          terminal cancer patients to various therapeutic measures
          has been more positive than the response among those
          who consumed shark cartilage.

This statement is also narrower than the first two, but broader
than the last statement. While it is specific in stating that no
therapeutic measures have received more positive response than
shark cartilage, the statement is limited to the past 20 years and to
terminal cancer patients. Note also that just because shark cartilage
has received a more positive response than any other therapy does
not tell us how successful shark cartilage therapy has been, or
mean that other therapies were unsuccessful—they could have
worked very well but not quite as well as shark cartilage.

Of the four statements above, the first two are global and can never be
violated. The last two are possible sources of wrong answers as they are
specific enough to eliminate certain statements, but open enough to allow
for a variety of possibilities. The makers of the test love to play with these
“edges,” and you should make sure that the answer you select directly
violates a statement in the stimulus.

Answer choice (A): This is the correct answer. The answer violates the
second sentence of the stimulus, where the author indicates that sharks
have a “greater resistance to cancer than any other organism.” This
statement means that no other organism matches or exceeds the cancer
resistance of a shark.

Answer choice (B): This answer focuses on the susceptibility of an
organism to cancer. Other than stating that sharks are the least susceptible
to cancer (greatest resistance = least susceptibility), we know nothing
about the cancer susceptibility of any other organism. Hence, this answer
is possibly true and therefore incorrect.

Answer choice (C): The third statement in the stimulus notes that shark
cartilage contains the inhibiting substance. There is no mention that other
organisms do not have the substance or that the substance is the primary
reason that sharks are cancer resistant. Thus, this answer choice could be
true and is incorrect.

Answer choice (D): From the discussion of the fourth statement you know
this answer choice could be true. Accordingly, it is incorrect.

Answer choice (E): The stimulus addresses sharks and cancer resistance.
Although cancer resistance would logically have some connection to
the immune system, cancer resistance is only one aspect of the immune
system and therefore other organisms could have an immune system that is
overall more efficient than the shark’s immune system. Consequently, this
answer choice is possibly true and therefore incorrect.

[cboles]

I chose D for this question because the stimulus doesn't mention anything about "many sorts of therapy." It just discusses their success in consuming shark cartilage. That being said, why is A right?

[Jonathan Evans]

Hi, Cboles,

Here you must read the stimulus carefully: "If the claims made above are true, then each of the following could be true EXCEPT"

Whenever "EXCEPT" is in the question stem, you must pause to consider what effect this term has on the task. Often when I encounter a word such as "EXCEPT" or "LEAST" in all caps, I will circle it and remind myself to reread the question stem before picking a final answer.

In this case, the question stem instructs you to find which answer choice Cannot Be True/Must Be False.

From the stimulus, you know "[sharks] have a greater resistance to cancer than any other organism." Therefore, answer A ("No organism resists cancer better than sharks do, but some resist cancer as well as sharks") contradicts this fact, so it cannot be true. It is the credited response.

Answer choice D is possible. It's simply something we don't know anything about. As you noted, it's not in the stimulus. It could be true. It might not be true. Who knows? We do not have sufficient information to prove that it cannot be true.

[SammyWu11201]

Hello. I'm having trouble wrapping my head around why the correct answer choice is A. In the analysis given in the book on page 628 in the 2020 edition of the second sentence in the stimulus, it says that NO OTHER ORGANISM has a greater resistance to cancer than sharks. However, it then proceeds to select answer choice A to be correct. Answer Choice A states that no organism resists cancer better than sharks do, but some resist cancer as well as sharks. This is true according to the analysis given for the second sentence in the stimulus, and therefore it does not match the question stem of selecting an answer that could be true EXCEPT.

Consequently, I don't understand why answer choice B is incorrect.

[Frank Peter]

Hi Sammy,

If sharks "also have a greater resistance to cancer than any other organism" then it cannot be true that "some [organisms] resist cancer as well as sharks" By saying that sharks have a greater resistance, it must mean that we can't have another organism that does as good of a job as sharks do in resisting cancer.

[lemonade42]

For (C), I'm not understanding why "no mention that... the substance is the primary reason that sharks are cancer resistant" would lead to (C) being incorrect. So if the stimulus said the substance is the main reason that sharks are cancer resistant, and even if you combine it with the fact that sharks have the greatest cancer resistance, wouldn't that still allow for the possibility that the substance is found in most organisms (which is C)? Because it's not saying the substance was the only reason for cancer resistance.

[Chandler H]

For (C), I'm not understanding why "no mention that... the substance is the primary reason that sharks are cancer resistant" would lead to (C) being incorrect. So if the stimulus said the substance is the main reason that sharks are cancer resistant, and even if you combine it with the fact that sharks have the greatest cancer resistance, wouldn't that still allow for the possibility that the substance is found in most organisms (which is C)? Because it's not saying the substance was the only reason for cancer resistance.

Hi Lemonade42,

It certainly is possible that the substance is found in most organisms. The sentence in the official explanation about the substance being "the primary reason that sharks are cancer resistant" may have been confusing; the point of including that sentence was to draw attention to the fact that "sharks have the greatest cancer resistance" and "other organisms have the same substance that inhibits tumor growth" are not mutually exclusive statements.