Quizzes not matching to material covered

I have been working through the Biochemistry section of MCAT prep for the past week. In every topic I have noticed that the review quiz questions do not always match to material covered in the videos. More than that, the questions use so many terms and topics that were not even stated in the videos, making it impossible to review the material learned. I'm really doubtful that I've properly learned any of the topics thus far, and the situation is becoming very frustrating. Is there no explanation for this? Are there different videos that aren't posted?