To pass HL biology, you need to know some serious details for each topic. In terms of chapters there is a few predictions you can make:
1)Photosynthesis or Respiration
One of these 2 generally comes up in some form or another. They are VERY complicated as there is a lot of cellular events taking place. As these topics don't have any obvious large scale analog in our lives, its very hard to wrap your head around certain parts, or to imagine it happening without a real frame of reference. What might help are videos on youtube that simplify these topics and show you what is happening. Online videos is a crucial resource for being able to view things to get your head around them. Try this for photosynthesis:
In fact the entire channel has some great videos about each topic.
2) DNA might come up in some form or another, specifically protein synthesis. Check these out for this topic:
https://www.youtube.com/watch?v=NJxobgkPEAo or else https://www.youtube.com/watch?v=gG7uCskUOrA to see these cell processes visually
3)Genetics is also a big one that might come up
4)You will also get questions on human or plant reproduction so it is a good idea to know a bit about both. Again, if you are stuck, use videos on the net to help you get your head around it.
It might take you 5 - 10 minutes to read up on something in your book, but you might get more out of a 2 minute video looking at the same thing being described. Especially if you are a visual learner.
If possible, you can try learning the diagrams in these chapters, and write your answers based off and around the diagrams. This is also a helpful method if you are a visual learner.
If you learn better via auditory learning, maybe try listening to these video a few times. Or else, record yourself saying what is happening on your phone, and listen to it a few times. Even put it on an mp3 player or ipod to listen to it over and over.
Half of the battle with this stuff is figuring out the best way you learn in addition to what you have to learn