Just make separate quizzes for each subsection and use completion and restrictions to open up the next quiz on completion on the next. The gradebook can be handled with categories or using weights in natural grading.
i am looking for the same functionality. but i think at this time moodle dont support it.
There are many users who are looking for this feature and from last 5 to 6 years. But I really disappointed why moodle is not taking this issue io into consideration. As this feature is must nowadays , i hope that someone from moodle team will take interest into this request.
For old thread look at this .Discussion.
Enter it in tracker and then try and get people to vote for it.
Or, join the Moodle User's Association and suggest it as a project there.