Learning science is language intensive. Students might have to interpret the meaning of models, support claims with evidence, communicate arguments, and discuss phenomena and scientific principles. For English Language Learners (ELLs), engaging in scientific and engineering practices includes additional challenges. This article describes a series of lessons that incorporates text selected to deepen student understanding of the role of sexual reproduction in genetic diversity and to develop students' disciplinary literacy. The lessons were designed and carried out in courses in sheltered biology, academic biology, and honors biology. Five steps taken to create the lessons: text selection, text analysis, exploring the concept of genetic variation, engaging students with the text, and assessment.