No, it is the other way around: you can define a structure within a function.
In C++ though, structs are actually classes, so they can have methods.
yes
No. Functions should be defined separately. So you would not define a function within a function. You can define one function, and while defining another function, you can call the first function from its code.
An organelle is a structure that is found within a cell and serves a specific function.
A structure performing a specific function within a cell is called an organelle.
Vestigial structure is used in application to structures that are determined genetically but do not have the ancestral function.
organelle
organelle
An organ is a structure that has a definite form and performs a definite function or functions within the body.
within its internal structure.
organelle
the cell
That would be an organelle