What is Anatomy of flowers?

And Modification of root?

Modification of Root means that root has modified itself according to its function. Some roots can store food, Some can respire, some can provide storage etc.
refer to the link for studying topic:
https://www.askiitians.com/biology/morphology-of-flowering-plants/root.html

In anatomy of Angiosperms( flowering plants) you study the internal tissue system of root stem and leafs.