GENETIC INFORMATION, VARIATION AND RELATIONSHIPS BETWEEN ORGANISMS
There are quite a few different but inherently related sub-topics in here. As this DNA contains the code to produce our characteristics, it stands to reason that this will be the primary focus. SO you need to understand how it is packaged and used within a cell, and how changes can be introduced to the code. This naturally leads on to the differences between organisms, resulting in the need to understand how organisms are classified and how they vary within a given ecosystem (i.e. biodiversity).
Use the worksheets alongside your textbook and revision guide. The presentations are more for teacher use but students may also find something useful in them.