Which prefix indicates "unequal"?

The prefix that indicates "unequal" is "aniso-". This prefix is derived from the Greek term "anisos," which means uneven or unequal. It is commonly used in medical terminology to describe conditions or characteristics that are not uniform or are variable. For instance, in terms like "anisocytosis," which refers to the presence of red blood cells of unequal sizes, the prefix accurately conveys the idea of inequality or variability that is being addressed.

In contrast, the other prefixes do not convey the meaning of "unequal." "Amphi-" typically refers to something that is both or on both sides, "eu-" signifies something good or normal, and "meta-" often indicates change or transformation. Therefore, "aniso-" stands out as the correct prefix for indicating disparity or lack of equality.