In this study, we investigated the optimal placement of animations and practice and feedback exercises with respect to each other and to static text and graphics in an online DNA replication module. We randomly assigned students in a first-semester introductory biology course for freshmen biology majors and nonmajors to one of four online modules with animations and practice exercises (assets) either embedded with the text and images or saved until the end after all the text and images. Although we expected to find that embedding assets with text and images would improve learning outcomes, we were surprised to find that outcomes did not change with the location of these assets with respect to the text and static images. Instead, we found that colocation of exercises with animations was correlated with the biggest student learning gains, independent of where these assets appeared relative to the static text and static images. This held true both for immediate posttest scores and delayed application questions on a midterm exam. Our findings could have potential implications for how to best design online learning modules that feature multiple assets.