question_answer 26)

  Roots obtain oxygen from air in the soil for respiration. In the absence or deficiency of O^, root growth is restricted or completely stopped. How do  the plants growing in marsh lands or swamps obtain their 0^ required for root respiration?

Answer:

                      Very Short Answer Type Questions                                       The roots of the plants (e.g., Rhizophora) growing in marshy/swamp areas becomenegatively geotropic. They grow vertically upwards in air, above the soil level and respire socalled respiratory roots or pneumatophores.