Question

Fatty substance found in epidermal cell walls is
(a)Cutin
(b)Suberin
(c)Wax
(d)Both B and C

Answer 1

Hint: Fatty substance is found in the epidermal cell walls because it forms a water-impermeable protective covering in that region. This substance is also seen in many fruits such as apple, cherry, etc which gives them a glossy appearance.

Complete Answer:
A fatty substance found in the epidermal cell walls is cutin. Cutin along with suberin and lignin is a chemical found in higher plant epidermal and periderm that forms a protective barrier. Cutin is a waxy polymer made up of omega hydroxy acids and their derivatives and is a major component of the cuticle. It is secreted by the epidermal cells and serves as protection against excessive water loss and pathogen attack. It is most commonly seen in plant parts like leaves as water loss through transpiration is highest there.

Additional information:
Let us learn more about epidermal tissue.
-The outermost covering of the plant body is made up of epidermal tissue and it consists of epidermal cells, stomata, and appendages like the trichomes and hairs.
-The epidermis is usually single layers and made up of long elongated cells that form a continuous layer.
-The outer surface of the epidermis is often covered with a waxy substance known as the cuticle but it is not present in roots.
-Stomata are pores present in the epidermis of the leaves and they are responsible for transpiration and gaseous exchange. The stomata along with the guard cells and surrounding cells make up the stomatal apparatus.
-The epidermal cells can have unicellular hair extensions like root hairs or multicellular structures like trichomes seen in the stem.

So, the correct option is ‘Cutin’.

Note:
-Suberin is a polyester that forms a major component of cork and is named after the cork oak Quercus suber.
-The cells of the endodermis (innermost layer of cortex) have deposition of suberin on them known as Casparian strips.
-Casparian strips are the only way to cause the movement of water to become symplastic (inside the cell) in the endodermis.