Final answer:
In grafting, the scion (stem of the desirable plant) is grafted onto the stock (rooted plant) by cutting and fusing their vascular systems.
Step-by-step explanation:
In grafting, the scion (stem of the desirable plant) is grafted onto the stock (rooted plant). The scion and stock are cut at an oblique angle, placed in close contact, and held together. The vascular systems of the two plants grow and fuse, forming a graft.
For example, in viticulture, scions capable of producing a particular fruit variety are grafted onto root stock with specific resistance to disease.