#24 - Scientist: Some consumer groups claim that the economic benefits

[Administrator]

Complete Question Explanation

Weaken. The correct answer choice is (D).

In this stimulus, a scientist argues that the risk of health problems from genetically engineered foodstuffs is minimal. Their support for this conclusion is that in most cases, only a single gene in a plant's genetic structure is changed, and since this change is so slight, it cannot have effects significant enough to be worrisome.

My immediate response to this is, how do we know? I'm not convinced that a single gene is necessarily insignificant because it's just one gene. Sure, it's possible, maybe even likely, but we're being asked to take this scientist's argument for granted, and I'm not convinced. If I were to prephrase an answer to this weaken question, I would look for something that says that just one gene can, in fact, be significant enough to render a foodstuff unsafe if tampered with.

Answer choice (A): This answer choice provides an irrelevant detail about genetically engineered plants that mentions nothing about the capacity of a single gene or health risks. Skip.

Answer choice (B): Careful--all this answer choice is saying is that any potential health risks may be reduced by other factors, but these health risks might still be serious enough to make the foods unsafe to eat. In addition, the phrase "may be" is a huge issue here--this means that there may not be any factors to reduce the health risks at all! Hard skip.

Answer choice (C): This is a tempting answer, but scientists don't necessarily need to know which exact gene determines every possible characteristic. They may only know the responsible genes of a few characteristics, and that is enough for them to genetically modify a foodstuff to their satisfaction. Overall, scientists not knowing this information does not necessarily mean that one gene, if altered in that plant, can produce adverse health effects. Let's see if there is a stronger answer choice out there.

Answer choice (D): This is the correct answer choice. Boom, this is exactly what we're looking for. This answer choice says that there are plants that can be toxic to some animals whose toxicity is affected by the alteration of a single gene. This answer choice makes clear that one gene alone, if altered, can cause a plant to be unsafe for animals (like us!) to eat. If you disagree with the argument that humans are animals, it's very possible that we may eat the animals who eat these plants, thus bringing the health risk to us (albeit indirectly).

Answer choice (E): This is a completely irrelevant factoid about consumers who are strongly opposed to genetically-altered foods. Skip.

[nguyenpcindy]

I was struggling to choose between C and D, but ultimately chose C. I could see that the Weakening point is whether or not a slight alteration can have significant or negative effects. Though I see now that D basically captures that prephrase, I initially dismissed it because to referred to animals and plants, not necessarily the effects of GMO plants to humans.

Given this, I turned to C, which I had interpreted that if we don't know the precise locations for genes -- say a gene that controls whether or a plant is toxic or whatever -- then when we alter genes, how do we know that it didn't affect the "bad" gene?

Am I stretching answer C too much to fit my pre-phrase?

[Robert Carroll]

nguyenpcindy,

Answer choice (C) just says that scientists don't know the function of every gene. But they might know the functions of the genes they're altering - in fact, that seems rather likely, as they'd likely only alter the genes that they know would produce a favorable effect on the foodstuffs thus engineered. So in answer choice (C), altering genes might not always be a positive thing (it's unknown how it would work in some cases), but we don't have much reason to think that the altering of foodstuffs would involve those unknown genes. Answer choice (D), on the other hand, makes it that a single gene really does often make the difference for toxicity, so the risk of altering a single gene is pretty high.

As you recognized, answer choice (D) really does match your prephrase. The question type of Weaken. An "overinclusive" answer can't be bad for a Weaken - if plant and animal genes are thus affected, then plant genes for plants used as foodstuffs will also be covered. So the broad language is not a bad thing.

Robert Carroll

[christinecwt]

Hi Team - may I know wh Answer Choice B is incorrect? Thanks!

[katehos]

Hi Christine!

Simply put, answer choice (B) is incorrect because it is neutral towards, or perhaps even strengthens, the scientist's conclusion that genetically engineered food has minimal health risks. Answer choice (B) asserts that health risks associated with genetically altered plants can be at least partially offset by additional nutritional benefits, which supports the scientist's general opposition to the claims of 'some consumer groups.' Of course, it's important to note that the scientist isn't arguing that the consumer groups are wrong because health benefits outweigh health risks (in this case, (B) would strengthen the argument), but rather the scientist is arguing that these health risks don't really exist at all (in this case, (B) might strengthen the argument by showing that whatever minimal risk remains can be offset somewhat by added benefits; though not quite as clearly as in the previous example). So, at a bare minimum, this answer choice does not hurt the argument.

Since we are looking for something that weakens the argument, we can eliminate answer choice (B) and instead find that (D) is correct.

I hope this helps!
-Kate

[goingslow]

Is (D) out of scope because it talks about toxicity to animals, not humans, since we're concerned with "hidden health risks to humans"?

[Adam Tyson]

Humans ARE animals, goingslow! Answer D is not out of scope at all, but is exactly what we need and is the correct answer. If one gene can have that much of an impact, then the scientists' claims that "come on, it's just one gene, that's no big deal!" looks pretty weak.

That human/animal thing is an old favorite of LSAC, btw. They know that some students will mistakenly treat humans as somehow being different from animals, rather than being a type of animal. To distinguish humans from the rest of the animal kingdom, they would have to say "non-human animals," and even then we would still find information about other animals to be of at least some interest. If it's true about, say, apes and dogs, might it also be true for us? It sure would make me think twice! After all, scientists do all sorts of laboratory testing on non-humans (rats, pigs, etc.) to help us understand what might happen to people under similar circumstances.

[goingslow]

Thank you for the point on humans and animals! Much appreciated.

[nivernova]

I have a question.

I considered D as a very strong contender but ended up choosing C instead.

The reason was that, even if the plants' toxicity was affected by the alteration of a single gene, as D argues, there seemed no way to find out whether the effect of the alteration was a positive or a negative one....

Please help me with that!

[Robert Carroll]

nivernova,

I don't see a defense of answer choice (C) in your answer, only criticism of answer choice (D), so for why answer choice (C) is wrong, I'll refer you to my previous post in this thread.

As to your objection to answer choice (D), it seems beside the point whether the alteration was positive or negative. If the alteration is positive, then not altering the gene would leave the plant at a higher level of toxicity; if the alteration is negative, then altering the gene would increase its toxicity. Either way, the toxicity of a plant is affected by the alteration of a single gene. Thus, a single gene's being altered (or not altered) can be the difference between levels of toxicity. And that would be terrible for the argument, which thinks that one gene's being altered can't have such a devastating effect.

Robert Carroll