Asks a thoughtful question, refers to specific information from the article, adds your own ideas or reasons for asking the question or indicates what you would need to test/think about in order to answer it.
Example: In experiment 3 the bees were starved for 4 hours before being tested, in order to test if the dancing behavior increased due to the floral scent. Why was this the only experiment in which they had not eaten, and is it possible that the effect of the higher responses in the cocaine treated bees was due to more hunger rather than as the mechanism that increases dancing behavior?
EXCERPT:
Not only does eCO2 reduce the plant mineral content, but it also alters plant stoichiometry. Specifically, the effect of eCO2 on N is nearly twice as large as its mean effect on minerals. The differential effect of eCO2 on N (15%), and P (9%) and S (9%) translates into a ∼7% reduction in the plant N:P and N:S. In contrast to the lower N and mineral content, eCO2 increased C content by 6% (Figures 2, 3 and 5). It follows then that eCO2 increases C:P and C:S by 16%, and C:N by 25% confirming the previous findings of 19-27% higher C:N in plants grown in eCO2