Your genetics book has a companion website that will help you to study more effectively. Go to this link:
On the left side of the page there is a drop down menu that will let your choose a chapter from the book. There are practice quizzes, powerpoints for each chapter, and many other resources available there to help you. These materials can be used to prestudy and also to review and test your understanding of concepts.
For the chemistry class, the website is:
For this site, the chapter overviews would be a good place to start.