question_answer 52)

  A nail is inserted in the trunk of a tree at a height of 1 metre from the ground level. After 3 years the nail will (a) move downwards                                                     (b) move upwards           (c) remain at the same position                                 (d) move sideways

Answer:

  (c) When a nail is inserted in the trunk of a tree at a height of 1 metre from the ground, even after 3 year the nail remains at same level. It does not moves upwards as the apical meristem responsible for growth (length) is present in the apices only and lateral meristem responsible of increase in girth will lead to no change in length.