One recommendation for better preparing English language learners (ELLs) for scientific fields is to capitalize on Spanish speakers' knowledge of cognates. However, little is known about the presence of cognates in high school biology content. This study examined the linguistic basis of 968 terms co-occurring in at least one of four textbooks and one of five sets of biology standards. Approximately 85.5% of terms were Spanish-English cognates, another 7.5% were partial cognates, and 1% had false cognates. Most terms were low frequency in both English (91%) and Spanish (89%). The discussion addresses the implications for teaching ELLs academic language and science content.