RC Question 21 Explanation
DISCUSSION: There were multiple proposed causes: brevetoxin, PCBs, bacteria. You need to find one mentioned by both theories.
___________
- Only the researchers mentioned the dolphins’ diet (lines 29-31).
- The dolphins died off the Atlantic coast; the researchers never mentioned the Gulf of Mexico. The author mentioned that P. brevis in the Gulf of Mexico didn’t kill dolphins (lines 42-44).
- The author points out that the dolphins started dying before the red tide (lines 45-47).
- CORRECT. The researchers mention PCBs on lines 35-37. The author mentions pollutants on line 53-56. The author specifically names PCBs as harmful on lines 49-51.
- The author’s alternative explanation on lines 52-60 does not mention bacteria.
Hello,
I’m confused by this one, because the question is “which one of the factors is explicitly cited as contributing to the dolphin’s deaths in both theories discussed in the passage”? The Researchers analyzed synthetic pollutants (PCBs) as being a possible cause, but concluded that the deaths were most likely caused by the brevotoxin poison, not PCBs. Therefore, I don’t think this theory cites the PBCs as specifically contributing to the dolphin’s deaths, because they’re saying it was caused by something different.
Can you please let me know your thoughts on this?
Thanks a lot,
Hi!
The researchers’ theory does explicitly cite synthetic pollutants as contributing to the death, even though they ultimate conclude brevetoxin was the primary cause. Towards the end of paragraph 3, it says that releasing stores of synthetic pollutants, like PCBs, further exacerbated their condition. That’s an explicit contribution to the chain of events that led to death in the first theory.
The key word in the question is “contributing to”, which is the exact language used when describing pollutants’ role in the researchers’ theory. So they do in fact believe that synthetic pollutants CONTRIBUTED to their death, even though it wasn’t the ultimate cause.
The alternative theory also clearly relies on pollutants as explained by Graeme (happy to provide further clarification on why but I don’t think your question related to the alternative theory/the author’s theory).
Hope that helps! Let me know if you have further questions.