The purpose of this mixed-methods study was to examine the extent to which text condition influences reading comprehension of life science text for 72 4th grade students and to understand their meaning making of each text condition. A three-paragraph passage on the circulatory system was presented in three different diagram types/conditions. All conditions were compared to a text-only control condition. A prior-knowledge task was used in order to identify pre-existing differences in students' background knowledge of the circulatory system and to then account for those differences statistically during data analysis. Following the prior knowledge task, a reading of one of the text conditions was completed followed by a comprehension post-test on the circulatory system. Following the post-test, a sub-group (n=15) of the original sample completed a verbal protocol to qualitatively assess meaning making from each text condition. The findings of this study could potentially benefit teachers, teacher educators, and researchers alike, as reading across the disciplines presents unique challenges given the demands that informational texts present for young readers. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]