Animal feed should not include genetically modified plants. A study found that laboratory rats fed genetically modifi...

Victoria on May 28, 2019

Hello @Aidyn-Carlson,

E is incorrect because it is irrelevant to the argument. The passage concludes that animal feed should not include genetically modified plants and cites the study on laboratory rats as evidence to support this conclusion. It does not matter whether the researchers could explain their results or not. Science often provides results which cannot entirely be explained by researchers. In addition to this, the passage states that the negative conditions included by the genetically modified potatoes are sufficient evidence to support the conclusion that animal feed should not contain genetically modified plants; it does not matter how the genetic modifications caused the intestinal deformities or weakened immune systems, nor does it matter if the researchers can explain why this might be the case. What matters is that these negative conditions appeared to be caused by the rats' consumption of the genetically modified potatoes.

A is the correct answer because it provides an alternate explanation for why the laboratory rats who were fed genetically modified potatoes developed intestinal deformities and a weakened immune system, and the rats who were fed the normal diet did not. If potatoes are not a normal part of the diet of laboratory rats, then the laboratory rats who were fed the regular diet may not have consumed potatoes and the laboratory rats who were fed the genetically modified potatoes may have developed these conditions because of the introduction of a new food into their diet, regardless of whether it was genetically modified or not.

Hope this is helpful! Please let us know if you have any further questions.

kens on April 9, 2020

Would it be correct to interpret that "normal diet" does not consist of potato, so the other group of rats did not consume any type of potatoes at all?

1127 on August 2, 2020

I have the same question as @kenken about interpreting "normal diet". Thanks!!!

shunhe on August 4, 2020

Hi @kenken and @1127,

Thanks for the question! Well, so the correct way to interpret “normal diet” is a diet that theoretically could have potatoes be a part of it, but is a diet that isn’t just of potatoes, and certainly doesn’t include GMO potatoes. So the rats that were fed GMO potatoes can be read to have being fed either just those potatoes, or a diet with GMO potatoes. Whereas the rats on the normal diet did not have GMO potatoes in any shape or form. So they could’ve eaten potatoes as part of that normal diet if that’s a thing that rats eat normally, but not GMO potatoes, and not just potatoes (there would’ve been a mix of foods).

Hope this helps! Feel free to ask any other questions that you might have.

kens on August 13, 2020

I apologize for the follow-up question, but I just wanted to confirm one thing. Does A weaken the argument because it could have been the potato, and not GMO, that caused the weakened immune system? Thanks in advance!

Victoria on August 19, 2020

Hi @kenken,

You are absolutely correct!

Keep up the great work and please let us know if you have any further questions.