Question

The diagram above is a three-dimensional representation of a cell found in many herbaceous plants.
Which one of the following descriptions applies to the cell shown above?

• A. A xylem vessel, produced during secondary thickening
• B. A phellogen cell with a thickened wall
• C. An endodermal cell with Casparian strips
• D. An immature sclerenchymatous fiber

Answer 1

The correct option is C An endodermal cell with Casparian strips

Casparian strip refers to the band deposited on the radial and transverse walls of the endodermis and is made up of cell wall material. This deposit is chemically different from the rest of the cell wall.

While the cell wall is mostly made up of lignin the Casparian strip is made up of suberin which is a lipophilic biopolymer and acts as a protective barrier against excessive water loss. The suberin in the Casparian strip prevents the passive flow of materials, like water and solutes, into the stele. This selective passage of solutes helps in preventing any type of harm to the plant. It was first recognized by Robert Caspary.