Question

Name the tissue which allows aquatic plants to float.

Answer 1

Hint: The tissue that allows the aquatic plants to float must be a large and hollow tissue. It is also important for nature to cover the leaves of aquatic plants with wax to avoid excess water intake by the cell.

Complete step by step answer:
-In the aquatic plants a large air cavity is present in parenchyma cells that give buoyancy to the plants and help them to float in the water. This type of parenchyma cell is known as aerenchyma.
-The aerenchyma cells of stems and roots serve as a storage centre for nutrients and water.
-The flexibility of these plants is provided by a permanent collenchyma tissue.
-The cells of aerenchyma of an aquatic plant make a network that has a wide air space or air cavities which help in gaseous exchange.
-These air cavities of aquatic plants allow the plant to be light and buoyant which results in the easy floating of plants in the water.

Note:
-The major advantages of the presence of large air-filled cavities in an aquatic plant is to provide a low-resistance internal pathway that allows the exchange of gases between the plant organs that are present above the water and the submerged tissues.
-The above-mentioned characters allow a plant to grow without suffering the metabolic costs of anaerobic respiration in water.
-The oxygen that is transported through the aerenchyma leaks through the root pores into the surrounding soil which results in the small rhizosphere of oxygenated soil around the individual roots support microorganisms that can prevent the influx of possibly toxic soil components for example sulphide, iron, and manganese etc.