This article highlights how English language learners' (ELLs) prior knowledge can be used to help learn science vocabulary. The article explains that the concept of prior knowledge needs to encompass the ELL student's native language, previous science learning, native literacy skills, and native cultural knowledge and life experiences. Information is provided on how science teachers can use ELL's native languages, culturally familiar experiences, and concept mapping to assist in comprehension. A biome concept map and rubric are presented to help explain ways to better teach ELLs.