Self-study
A certain gene can be stimulated by chemicals in cigarette smoke, causing lung cells to metabolize the chemicals in a way that makes the cells cancerous. ███ ███████ ██ ████ ████ ████ ██ ███ ██████████ ████ ██ ████ █ ████ ██ ██████████ ████ ██████ ████ ███████ ██ █████ ███████ ███
Summary
A certain gene can be affected by chemicals in cigarette smoke.
When the gene is affected in this way, it causes lung cells to metabolize in a way that makes the cells cancerous.
Smokers in whom this gene is not stimulated have as high a risk of developing lung cancer from smoking as other smokers do.
Very Strongly Supported Conclusions
There’s no obvious conclusion to draw, but I’d observe that the facts seem to present a discrepancy. We’d expect that smokers in whom the gene is stimulated should be at a higher risk of lung cancer. The fact that they aren’t is strange. This suggests there might be something about the smokers in whom this gene is stimulated that might work to reduce the risk of lung cancer.
4.
If the statements above are █████ ██ ███ ██ █████████ ██ ███ █████ ██ ████ ████
a
stimulation of the ████ ██ █████████ ██ █████████ █████ ██ ███ ███ ████ ██████ █████████ ███ ████ ███ ███████ ██ ██████████ ████ ██████
This is strongly supported, because if it weren’t true, then we’d expect the smokers in whom the gene is stimulated to have a higher risk of lung cancer. The fact that they don’t implies that there are other factors relevant to lung cancer that might work to reduce the smokers’ risk.
b
nonsmokers have as ████ █ ████ ██ ██████████ ████ ██████ ██ ██ ███████ ██ ████ ███ ████ ███ ███ ████ ██████████
The stimulus compares the risk of lung cancer in one kind of smoker compared to another kind of smoker. We don’t get a comparison between smokers and nonsmokers.
c
smokers in whom ███ ████ ███ ████ ██████████ ███ ████ ██████ ██ ███████ ████ ██████ ████ ███ █████ ███████
The stimulus provides evidence against (C). Smokers in whom the gene is stimulated have “as high a risk” of lung cancer from smoking as other smokers do. This suggests the risk of lung cancer, at least from smoking, is equivalent in the two kinds of smokers.
d
the gene is ████ ██████ ██ ██ ██████████ ██ █████████ ██ █████████ █████ ████ ██ █████ █████████
The stimulus doesn’t compare what is more likely to stimulate the gene.
e
smokers are less ██████ ██ ███████ ████ ██████ ██ ████ ██ ███ ████ ███ ████
If anything, the stimulus provides some evidence against (E). Smokers in whom the gene is stimulated have “as high a risk” of lung cancer from smoking as other smokers do. This suggests the risk of lung cancer, at least from smoking, is equivalent in the two kinds of smokers.