Question

In which of the following plants would metabolism be hindered if the leaves are coated with wax on their upper surface

• A. Hydrilla
• B. Lotus
• C. Pistia
• D. Vallisneria

Answer 1

Answer: (B)

Lotus

Lotus is a partially submerged hydrophyte, rooted into the soil of the water body, the leaf floats on the surface of water and is covered with a layer of cuticle to prevent accumulation of water on the upper surface of the leaf.

It is through this surface transpiration and exchange of gases takes place with the help of stomata.

Covering of the leaf surface with wax will block stomata, stop stomatal transpiration and gaseous exchange on that surface in Lotus.

It will not take place in Hydrilla, Vallisneria as both are submerged hydrophytes and exchange of gases takes place through diffusion.

As Pistia is a monocot belonging to Aracaceae, the stomata are present in almost same number on both the surfaces, metabolic hindrance will be less compared to Lotus as stomata are absent on the lower surface of Lotus.

So, the correct answer is 'Lotus'