The student access for the teacher planning pages has just changed. 
Teachers can now turn  on/off  the student access to these page using the function "Add/Edit Content", in the same way as for model answer pages.

Some students may like using these pages (e.g. for revision or catching up on work),
but you may prefer to switch them off because you follow a different plan. 

So if you would like to turn these pages on or off, simply click the buttons in the Student Access area of the site: https://www.thinkib.net/biology/std-access

From this Student access page there is a sitemap showing colour coded pages.

Student sitemap

Blue pages are automatically available to students once you have created a student group; Orange pages are only available to students when you explicitly select them for a group; Gray pages are only for teachers.

You can change the Orange page properties to "available to students"
in the, "Add/Edit content" section of each group. 

Use the buttons on your page, shown with the yellow highlights below...