What Is Growth?v Growth is the increment in drymass, volume, length, or area that results from the division, expansion, and differentiation of cells. v Increment in drymassmaynot, however, coincidewithchangesin each of these components of growth. For example, leaves often expand and roots elongateatnight, when the entire plant is decreasingindrymassbecause of carbon use in respiration. On the other hand, atubermay gaindrymass without concomitant changeinvolume, as starch accumulates.v 生长（growth)
