Given a scientific passage and an answer, generate a question for the given answer.

Passage: Nobody really has such colorful eyes! The colors were added digitally after the photo was taken. They represent all the different colors of light. Light is a form of energy that travels in waves. Light of different colors has different wavelengths. Answer: wavelengths
Different colors of light differ in terms of which important attribute?

Passage: Figure 43.17 Rising and falling hormone levels result in progression of the ovarian and menstrual cycles. (credit: modification of work by Mikael Haggstrom). Answer: hormones
Rising and falling levels of what will result in progression of the ovarian and menstrual cycles?

Passage: Gene expression and protein synthesis are usually considered the same molecular process. Answer: protein synthesis
Gene expression and what else are usually considered the same molecular process?