In C++, calling a derived constructor creates a base object or not?

Question

#include<iostream>
using namespace std;
class Base{
    private:
        int x;
    public:
        Base(int i){
            x = i;
        }
        void print(){
            cout<<x<<endl;
        }
};
class Derived: public Base{
    public:
        Base b;
    public:
        //the constructor of the derived class which contains the argument list of base class and the b
        Derived(int i, int j):
        Base(i),
        b(j)
        {}
      
};
int main(){

    Derived d(11, 22);
    d.print();
    d.b.print();
    return 0;
}

why the the value x of the b is 11, the value x of the d.b is 22? if the constructor of base initialize the int x in class Base, is there a Base object exist? the argument list of the derived constructor, should be one argument or two when there is a Base b as class member?