Access to course sections

I'm about to install DupalEd to test this out, but I'm also wondering if there's somebody that has done this already.

I will need to have a course that is structured into several sections, each with several modules. The tutor will need to be able to give learners access to the modules in each section when (and only when) that have completed the modules in the previous section (by submitting an assignment, completing a quiz or some other task).

I'm not expecting this to happen automatically as there will still need to be some manual checking by the tutor, but they will need to be able to control which learners have access to which sections.

Is this possible in DrupalEd? Has anybody done it??

Thanks for any feedback....