Explain why most farmers use stem cuttings to plant new fruit trees rather than plant seeds.

The main reason that most farmers use stem cuttings rather than just planting a seed is that a tree's genetic variation will occur. The seeds of many fruit trees tend to vary differently from the parent, because seeds themselves are produced by sexual reproduction (i.e they receive genes from a male and female to form). As they are a cross from two sets of genes, many fruit trees are not “true to seed”. Their seeds will produce a generally different variety of tree from the parent. When using stem cuttings, it's almost like a cloning process.

cause the stem cuttings will spread like bulbs and its quicker.

Hi. The question you presented above is incomplete. This makes it impossible for this question to be answered. However, when searching for your question on the internet, I was able to find another question exactly like yours, which asked you to explain the evolutionary relationship between these three species. If that's the case for you, I hope the answer below will help you.

In a simplified way, we can infer that among the three species presented above, the third presented a faster evolution than the first two and this is what explains the difference between the gene sequences between the species. As the question presents, the three species have related genes, which indicates that they had a common ancestor, however the difference in the gene sequence of the third species shows that it evolved first, showing changes that cannot be noticed in the first two species that are evolving more slowly.