Question

In submerged hydrophytes, functional stomata are found
A. On lower surface of the leaf
B. On both the surface of the leaf
C. Nowhere on the plant
D. On the upper surface of the leaf

Answer 1

Hint: The free-floating submerged hydrophytes are the plants that grow below the water surface and have no contact with the atmosphere. They have specialized cells that are required for the intake of substances for the growth of the plant.

Step by step answer: Submerged or underwater rooted plants have limp or flaccid stems and most of the vegetative mass is below the water surface but some portions stick above the water. The gaseous exchange directly takes place from the cells of the body. They do not have stomata on their body surface. If stomata are present in submerged plants then, water would enter through the stomata into the plant. They have specialized cells on their surface which absorbs water, nutrients, and dissolved gases in the water. They are usually covered by a film of water. Some examples of submerged plants that do not have stomata are seagrasses and pondweed. Leaves of submerged plants are astomatic. Some of the hydrophytes are Hydrilla, Potamogeton, Isoetes and Vallisneria/, which remain completely submerged in water and rooted in soil. In Hydrilla, Potamogeton and Chara, the stem is long, bearing small leaves at the nodes.
Hence, the correct answer is option C.

Additional information: Hydrophytes can be classified as;
i. Free-floating hydrophytes.
ii. Floating but rooted hydrophytes.
iii. Submerged hydrophytes (floating and rooted).
iv. Amphibious hydrophytes.

Note: In submerged or underwater plants, the stomata is either absent or vestigial. Stomata are certain structures present on terrestrial plants mostly. They are used by plants for the exchange of gases. Other important processes, i.e. transpiration can also occur through these structures.