Question

Roots play an insignificant role in the absorption of water
(a) Sunflower
(b) Pistia
(c) Pea
(d) Wheat

Answer 1

Hint: Water absorption is the chief function of roots. But in hydrophytes, the role of roots to absorb water becomes negligible. Hydrophytes are the plants growing in water-abundant areas. They may be free-floating or rooted.

Complete answer:
There are three types of root systems in nature- tap, fibrous and adventitious. In the tap root system, the primary root or taproot from the radicle persists, which is the thickest and largest of all. It penetrates deeper into the soil. Later, lateral roots i.e. primary and secondary roots develop from the main branch. This type of root system is observed in dicots e.g. Pea, Sunflower.
In the fibrous root system, tufts of roots arise from a radicle which is nearly equal in size. The dense network of roots firmly holds the soil, thus, preventing soil erosion. Surface area for absorption greatly increases. Monocots usually portray the fibrous root system. E.g. wheat.
Adventitious root system involves the growth of roots from parts other than radicle. They can be aerial or underground. E.g. Lower nodes of stem bear roots to provide support to the plant in maize and sugarcane.

So, the correct answer is ‘Pistia.’

Additional Information: In aquatic plants, roots are shorter and lighter. Their tissues have intercellular spaces just like the rest of the cell to keep the plant drifting on the water surface. Also, they are not well developed like the roots of terrestrial plants. The root system is feathery to provide minimum turbulence to the flowing water. Stomata are never closed and cutin is absent because there is no need to conserve water. Uptake of raw materials for photosynthesis occurs from the dissolved gases in water.

Note: In aquatic plants, roots are shorter and lighter. Their tissues have intercellular spaces just like the rest of the cell to keep the plant drifting on the water surface. Also, they are not well developed like the roots of terrestrial plants. The root system is feathery to provide minimum turbulence to the flowing water. Stomata are never closed and cutin is absent because there is no need to conserve water. Uptake of raw materials for photosynthesis occurs from the dissolved gases in water.