I've gotten some UWorld questions wrong because I don't know whether error bars represent CI, SD, or SEM (to determine significance) since no where in the passage do they mention it.

For example they explain, "However, the results depicted in Figure 1 show no significant difference in the base selectivity between dTTP and its structural analog dFTP", without letting me know what the error bars represent.

I know if the bars overlap and represent SD, CI (2 SE) , data MAY or MAY NOT be statistically different. If they represent 1 SE, data sets are NOT statistically significant.

It looks like UWorld is explaining this as if these error bars represent 1SE, how was I supposed to assume that they don't represent SD or CI??

What approach should I take if I come across another situation like this on MCAT/UWorld?