Reading can be considered constitutive epistemology for science and a fundamental aspect of scientific literacy. This study attempted to give further insights into the comprehension of different genres of science texts (textbook and popular science) and the assimilation of the academic language by adolescent age students. The writings 14- and 15-year-old students produced after reading one of these two genres were analysed while controlling for their reading skills and gender. The results indicated that popular science text readers achieved better comprehension scores for some of the ideas provided by the texts and that the performance of boys and girls reading the popular science materials tended to converge for most of the text ideas. Furthermore, analysis of some attributes of scientific writing revealed significant linguistic differences in the writings produced by the readers of different text genres. Data interpretation implies that (a) the influence of text genre on reading comprehension can be restrained only to some of the text imparted propositions; (b) certain school science text genres were prone to reverse the well-known girls' reading superiority over boys; and (c) students can reproduce text characteristics in their writing that is more consistent with academic language. Overall, the findings presented favour a view that science reading is a complex phenomenon that merits more in-depth research.