Question

Cuticle is always present on the surface of
A. Root
B. Leaf only
C. Steam only
D. Leaf and stem

Answer 1

Hint:Epidermis is the outermost layer of the primary plant body. It is usually single-layered,i.e., composed of a single layer of epidermal cells. However, it may be multilayered, i.e., composed of several layers of epidermal cells, for example, Nicus, Ficus. Cuticles are present on the surface of the epidermis.

Complete answer:
The outside of the epidermis is often covered with a waxy thick layer called the cuticle which prevents the loss of water because of the deposition of a waxy substance called cutin on the outer walls of cells. Cuticles are absent in roots and hydrophytes.
In dicot leaves the epidermis is present on both surfaces upper and lower surface. The epidermis is a single-layered, made up of parenchyma cells the outer walls of the epidermal cells are cuticularized.
In monocot leaves, the upper side and lower side both are covered with epidermis. Both the layers of the epidermis are composed of a single layer of cells and possess stomata. Both the layers of the epidermis are cuticularized.
In the dicotyledonous stem, the epidermis is the outer layer and is protective in function. It is made up of a single layer of cells. The outer walls of epidermal cells are cuticularized as they are covered with a thin cuticle.
In a monocotyledonous stem, the epidermis is the outermost layer which is made up of a single layer of cells covered with a cuticle.
The cuticle is always present at the surface of leaf and stem

So, a correct answer is an option (D).

Note: Transpiration in which water vapours are also lost directly from the outer walls of the epidermal cells through the cuticle is known as cuticular transpiration. The cuticle is a wax-like layer of cutin that covers the epidermis of leaves and stems. It reduces the water loss but may give out water vapors through the cracks. It commonly constitutes 3-10 percent of total transpiration.