Many valuable horticultural varieties of plants, including roses, rhododendrons, junipers, geraniums, and so on, are commonly propagated by inducing roots to form on cuttings taken from branch tips. This method involves cutting a few inches from the tip of a branch and inserting the cut end into moist sand or other substrate. Under the right conditions, roots may form from the cut end, giving a new plant generated from the stem cutting. In what way could this phenomenon be used to argue for or against the "genome reduction" hypothesis for cell differentiation?
Answer
In order to produce roots, the branch cuttings would have to alter gene expression patterns so that cells previously producing proteins necessary for the branch now produce proteins necessary for root development.