In this document you can find a good and short compilation of useful web pages to follow the 3ESO Biology and Geology Syllabus.
These references came either from http://www.bbc.co.uk/bitesize/ks3/
or from http://e-learningfoundation.skoool.co.uk/keystage3.aspx?id=63 .
Both sites are excellent biology resources.
This document with the links included could become a virtual text book for this level (3º ESO bilingual program) and it could also be used as a review guide for summer hollidays.