Given a scientific passage and an answer, generate a question for the given answer.

[Q]: Passage: Bone marrow is a soft connective tissue that produces blood cells. It is found inside the pores of spongy bone. Answer: bone marrow
[A]: What is found inside the pores of spongy bone?

[Q]: Passage: Saturated hydrocarbons contain only single bonds between carbon atoms. They are also called alkanes. They may form straight-chain, branched-chain, or cyclic molecules. Compounds with the same number of atoms but different shapes are called isomers. Answer: alkanes
[A]: What is another word for saturated hydrocarbons?

[Q]: Passage: Artificial Methods of Asexual Reproduction These methods are frequently employed to give rise to new, and sometimes novel, plants. They include grafting, cutting, layering, and micropropagation. Grafting Grafting has long been used to produce novel varieties of roses, citrus species, and other plants. In grafting, two plant species are used; part of the stem of the desirable plant is grafted onto a rooted plant called the stock. The part that is grafted or attached is called the scion. Both are cut at an oblique angle (any angle other than a right angle), placed in close contact with each other, and are then held together Figure 32.26. Matching up these two surfaces as closely as possible is extremely important because these will be holding the plant together. The vascular systems of the two plants grow and fuse, forming a graft. After a period of time, the scion starts producing shoots, and eventually starts bearing flowers and fruits. Grafting is widely used in viticulture (grape growing) and the citrus industry. Scions capable of producing a particular fruit variety are grated onto root stock with specific resistance to disease. Answer: scion
[A]:
During grafting, the part of the plant that is grafted is called?