Self-study
Biologists have noted reproductive abnormalities in fish that are immediately downstream of paper mills. ███ ████████ █████ ██ ███████ █████ █████ █████ ███████ █████ ███ █████ ███ █████ ███ █████████████ ██ ████████ ██ █████ ████████ ██████ ██ ████████ ██ ██ ███ ██████ █████ ███ ████ ███████ ██████ ███████ ██████████████ ██████████ ███████ ██████ ██████████ ████ █████████ ███ ██████ ██████████ ████ ██████ ██ ███ ████████████
Summarize Argument: Phenomenon-Hypothesis
The author concludes that dioxin released from paper mills is unlikely to be the cause of reproductive abnormalities in fish immediately downstream of the mills. This is because when the mills shut down, the fish recover normal hormone concentrations relatively quickly, even though dioxin decomposes very slowly in the environment (which suggests the dioxin didn’t just disappear quickly from the area).
Notable Assumptions
The author assumes that the dioxin is still present around the fish immediately downstream of the paper mill during the mill shutdowns. This is why the author thinks the quick recovery of the fish shows that dioxin isn’t likely to be the cause of the fish’s problems. The author also assumes that the reproductive abnormalities in the fish are caused by abnormal hormone concentrations.
12.
Which one of the following ███████████ ██ █████ ████ █████████ ███████ ███ █████████
a
Some of the ███████ ████ ████ ████ ████ ███████ ███████ ██████ █████████ ████ ██████ ██ █████ ██████████████
Whoever funded the studies doesn’t change anything about what the studies found. We have no reason to think the source of funding affected how the study was done in a way that would lead us to question the results.
b
The rate at █████ ██████ ██████████ ██████ █████████ ██ ███ ██████████ ██ █████ ██ ██ ████████
A premise already establishes that dioxin decomposes very slowly in the environment. Although the rate might not be exactly the same in all environments, we still know it decomposes very slowly. So, (B) doesn’t suggest that the dioxin might have decomposed quickly.
Illusory inconsistency
Illusory inconsistency
Answer is attractive because it seems to (but doesn't actually) contradict the premises or conclusion. In other words, it feints an attack on the premises or conclusion. If correlation is present, the answer choice is often merely an outlier datapoint, which is actually entirely consistent with the correlation.
c
Normal river currents █████ ███ ██████ ███████ ██ ███ █████ ███ ██████████ ██ █ ███ ██████
This shows dioxin might not be around the fish anymore during a shutdown. This is why the recovery of the fish during a shutdown does not constitute strong evidence that dioxin isn’t the cause. If dioxin isn’t around the fish at these times, that might be the reason fish recover.
Alternate explanation
Alternate explanation
Weaken: Introduce or support an alternate explanation for a phenomenon.
Strengthen: Helps to eliminate an alternate explanation for a phenomenon.
d
Some of the ████ ███ ███ ███████ ███████ ████ ███ █████████████ ███████ ████ ████ ███████ ██ ███ ███████ ██ ███████ ███████████████
One assumption is that the reproductive abnormalities are caused by hormone concentrations. Even if we interpret “physiological changes” as including reproductive abnormalities (which is not clear), this affirms a link between hormones and reproductive abnormalities.
Illusory inconsistency
Illusory inconsistency
Answer is attractive because it seems to (but doesn't actually) contradict the premises or conclusion. In other words, it feints an attack on the premises or conclusion. If correlation is present, the answer choice is often merely an outlier datapoint, which is actually entirely consistent with the correlation.
e
The connection between ███████ ██████████████ ███ ████████████ █████████████ ██ ███ ██████████ ███████████
The fact the connection is not thoroughly understood does not undermine the assumption that hormone concentrations cause reproductive abnormalities. The issue is not how well we understand the relationship; it’s about whether there exists a causal relationship.
Illusory inconsistency
Illusory inconsistency
Answer is attractive because it seems to (but doesn't actually) contradict the premises or conclusion. In other words, it feints an attack on the premises or conclusion. If correlation is present, the answer choice is often merely an outlier datapoint, which is actually entirely consistent with the correlation.