Question

Name the tissue which allows aquatic plants to float.

Answer 1

The aquatic plants are also called as Hydrophytes. They are mainly classified into fully submerged, partly submerged and free-floating plants. Aquatic plants have some special adaptations so that they can survive underwater. Some of the adaptations include poor root development, stems are usually modified into the rhizome, runner etc., leaves are generally narrow with the presence of mucous around them and the colour of the entire plant will be dark green-yellow.

Complete step by step answer:
The characteristic features of aquatic plants are as follows :
The adaptations can be easily observed in the anatomy of the hydrophytes.
Aerenchyma is specialized parenchyma cells which are air-filled. They provide buoyancy to the aquatic plants.
In the cross-section of aquatic plants, aerenchyma appears like a cavity. Each cavity is separated from one another using chlorenchymatous cells.
Some characteristics of aerenchyma are as follows:
The aerenchyma is filled with respiratory gases like carbon dioxide, oxygen.
The air chambers have the presence of cross septa called as the diaphragm which provides better aeration and is important in plant floating.
Aerenchyma not only helps in the floating of plants but also provides mechanical strength to the plant.
They are abundantly present in the hydrophyte fruit and hence help in the dispersal.

Note: Chlorenchyma, collenchyma, and aerenchyma tissue will sound alike but their functions are different. Chlorenchyma is a photosynthetic parenchyma cell. Collenchyma tissues are involved in providing structural support to the stem, leaves etc. Aerenchyma is present only in the aquatic plants which help in the floating of the plant.