Question

A characteristic feature of hydrophytes is
(a) Aerenchyma
(b) Well developed phloem
(c) Floating leaves
(d) Submerged leaves

Answer 1

They are a spongy tissue that develops spaces or air channels in the leaves, stems and roots of some plants, which permits exchange of gases between the shoot and the root. They are modified parenchyma.

Complete step by step answer:
Hydrophytes are the plants which live fully or partially submerged in fresh water. Such plants don't face the problem of water shortage. They need developed mechanisms for the removal of additional water from their cells. Aerenchyma is a spongy tissue which develops spaces or air channels in the leaves, stems and roots of hydrophytes. They have broad leaves with an outsized number of stomata on their upper surfaces. This characteristic helps hydrophytes to get rid of an extra amount of water. The foremost common example of such plants is water lilies.
Adaptations of hydrophytes are
-The main function of the basis system is to soak up water hence, due to abundant availability of water all around, the basis system is a smaller amount developed and water is absorbed from the plant surface. - In some plants like water- chestnut (Singhara or Trapa) the roots are green coloured, they carry photosynthesis. They’re referred to as the assimilatory roots. - In some plants like Lemna, roots carry out the action of balancing the plant body. - The leaves of the floating hydrophytes are wide while those of the submerged plants are dissected or ribbon shaped. - Air chambers are present within the internal structure of the leaves, stem and roots of the hydrophytes.
So the correct answer is ‘(a) Aerenchyma’.

Note: The osmotic concentration of the cells of hydrophytes is a smaller amount. Root hairs are absent and are replaced by root pockets in hydrophytes. In hydrophytes pollination and dispersal of seeds and fruits is through means of water, therefore their seeds and fruits are light in weight. The stem is soft, thin and versatile in hydrophytes.