Question

Which of the following is well developed in hydrophytes?
A) Aerenchyma
B) Collenchyma
C) Stomata
D) Root system

Answer 1

Hint: Those plants which can live in water and adjust to their surroundings are known as hydrophytes. They either remain fully submerged, for example, hydrilla or are found in Vallisneria, whose most of the body remains underwater.

Complete answer:
Hydrophytes are adapted to live either in waterlogged soils or partly or wholly submerged underwater. They can absorb water from the surface and lack stomata. Aerenchyma is a type of Parenchyma found in hydrophytes that are plants living in the water bodies. This is specialized tissue in which large air cavities are formed by the cells of these tissues. These air cavities are filled with air. The plants become buoyant due to the presence of sir which helps them to float and it facilitates the gaseous exchange also.

Collenchyma is an elastic, living, mechanical tissue. The cells of this tissue are called collenchymatous cells which may be oval, spherical or polygonal in shape. The intercellular space is absent because these cells are closely packed with each other. At the corner of these cells, thickenings of cellulose, Hemicellulose and pectin develop due to which the cell walls become thick at corners. Cellulose, hemicellulose and pectin are complex carbohydrates that provide strength to the Walls.

Stomata: These are minute structures present in the epidermis of leaves. They are absent in the epidermis of roots. Each stomach is composed of two best shaped or kidney-shaped cells known as guard cells, and a tiny stomatal pore.

Root system: It is formed on the basis of similarity in function or structure. It is of three types. tap root, fibrous and adventitious root.

Therefore the correct answer is option ‘A’.

Note: The other characteristics of hydrophytes are-
- The stomata is mostly open throughout.
- They have broad and flat leaves which float on the surface of water.
- The thin cuticle is present on the surface of the leaves.