The diet of Heliothis subflexa

Answer choices

1. A

   Contradicted7% picked this

   H. subflexa caterpillars synthesize Iinolenic acid within

   We believe that Helio doesn't have any linolenic acid in their bodies (at least none from their diet). So we definitely don't have any support for the idea that they create it within their bodies. This answer seems to be trying to bait people into thinking, "All insects need linolenic, but Helio doesn't get any of it in its diet, so Helio must just produce it within its body." But we were never told all insects need linolenic, just many insects, not-including Helio.

   7%
2. B

   Correct72% picked this

   Most species of caterpillar have sources of linolenic acid in

   Why this is right

   Usually, the word "most" is a toxic red flag on Must Be True / Most Supported / Necessary Assumption / Reading Comp, because usually the passage has never specified something as quantitatively precise as most. However, we did get a fact about most caterpillar species in the final sentence, so maybe we can say something about "most species of caterpillar". We know that most caterpillar species have volicitin in their saliva. Producing volicitin requires linolenic acid in an insect's diet. So, sure, we can derive that most species of caterpillar have sources of linolenic acid in their diet. How come we didn't predict that one on the front end, given that "volicitin" was a common ingredient of the 3rd and 4th sentences? It was because the paragraph is centered around Helio, which gives off the impression that the answer will relate to Helio.

   Skill tested: Must be True · how this choice captures the argument's function is the move to repeat next time.

   72%
3. C

   Illegal Reversal One-Claim Support15% picked this

   Any caterpillar that has linolenic acid in its diet has volicitin

   If you have volicitin, then you must have linolenic acid in your diet. Volicitin requires linolenic acid, which looks like this: Volicitin → linolenic acid This answer choice is just doing an illegal reversal of that conditional: linolenic acid → volicitin We should have felt icky about considering this answer, since it would be deriving its support from only one claim ("linolenic is necessary for the production of volicitin"), and we know that almost all correct answers on Must Be True and Most Supported derive their support from at least two claims.

   15%
4. D

   Out of Scope: poisonous3% picked this

   A food source containing linolenic acid would be poisonous to H.

   We know that Helio caterpillars don't have linolenic acid in their diet, but we can't say that linolenic acid is therefore poisonous to them. I don't have okra in my diet (because I never think to buy it and don't know how to cook it), but that doesn't mean it's poisonous to me.

   3%
5. E

   Too Strong3% picked this

   No caterpillars other than H. subflexa eat fruit from plants of

   Too Strong: no others Only Thing Mentioned ≠ Only Thing The only caterpillar mentioned that eats fruit from Physalis is H. subflexa, but that gives us no license to infer that H. subflexa is the only caterpillar that eats such fruit. Similarly, saying "Joe Biden grew up in Pennsylvania" does not give us license to infer that "No other U.S. Presidents grew up in Pennsylvania".

   3%