question_answer 52)

Minerals absorbed by the roots travel up the xylem. How do they reach the parts where they are needed most? Do all the parts of the plant get the same amount of the minerals?

Answer:

                  The minerals absorbed are transported up the stem, to all parts of plant through thetranspiration stream. The chief sinks for the mineral elements are the growing region ofthe plant, such as the apical and lateral meristems, young leaves, developing flowers,fruits, seeds and the storage organs. Unloading of the mineral ions occurs via fine vein endings through diffusion and activeuptake by the cells. In plants, xylem are involved in transport of inorganic nutrients wherephloem transport only organic materials. Mineral ions are frequently remobilised from older parts of plant like leaves to the youngerregions. Elements most readily mobilisal are phosphorus, sulphur, nitrogen, potassium,and some elements that forms the structure! component are not remobilised e.g., calcium.