These structures release cells that perform neutrophil-like functions by expelling extracellular DNA, called border cells. The movement of specialized organelles within the columella cells of these structures helps direct their growth according to the starch-statolith hypothesis. These structures can recover from damage by triggering the proliferation of stem cells located in quiescent centers. The lengthening of cells in the zone of elongation (-5[1])causes most of the growth of these structures, which often display positive (-5[1])gravitropism. These (-5[1])structures form symbiotic (10[1])relationships with fungi called mycorrhizae. (10[2])Material in these structures (-5[1])is transported (10[1])to the rest of the organism (10[1])through the xylem. For 10 points, name these structures that plants use to take up nutrients and water. ■END■ (10[3])