In the fall 2010 issue of the AI Magazine, we reported the design, implementation and evaluation of a knowledge acquisition system called AURA. AURA enables domain experts in Physics, Chemistry and Biology to author their knowledge, and a different set of experts to pose questions against that knowledge. The evaluation results previously reported were from 50 pages each from science textbooks in Physics, Chemistry and Biology. The results were most promising for Biology. Based on those results we undertook a content building effort to capture knowledge from approximately 315 pages (or 20 chapters) of college level Biology textbook and incorporated the resulting content in the electronic version of that book. In this presentation, I will first give an overview of AURA, give a quick demo of the electronic biology textbook and then discuss the knowledge base building effort and the challenges faced during the process.