What term describes the specialized aerial roots used by mangroves to facilitate gas exchange?

• A. Pneumatophore
• B. Holdfast
• C. Gas Bladder
• D. Frustule

Answer: (A)

Gas exchange in waterlogged mangrove sediments is facilitated by specialized aerial roots that rise above the mud to take in oxygen. These structures, called pneumatophores, protrude into the air and often have lenticels that allow oxygen to diffuse down to the submerged roots. This adaptation helps mangroves survive in anoxic soils where diffusion of gases in the mud would be very limited. The other terms don’t describe roots that handle respiration: a holdfast is for anchoring, a gas bladder is a buoyancy structure in some aquatic plants and algae, and a frustule is the silica shell of diatoms.