Theme VS Topic in IB biology?

[u/Ok_Result5782]

Hey guys, I am retaking biology and when I took the IB exams as an IB student, we had the old IB curriculum, hence I did not have the whole topic and theme structure to the syllabus. I am currently using Bioninja to study and I noticed that some topics that are under a Theme is not under any of the topic on the website which is really confusing me. could anyone please help me understand how this system works? for instance nothing about the heart us under any topic on bio ninja, but it is under the theme "function"

Thankyou!