In the figure below, the line with the arrowheads indicates the cell-wall pathway for an absorbed nutrient.
What structure actually regulates the entry of nutrients into the plant's interior?

Question

In the figure below, the line with the arrowheads indicates the cell-wall pathway for an absorbed nutrient. 
What structure actually regulates the entry of nutrients into the plant's interior?

Quizplus · Accepted Answer

The plasma membrane of endodermal cell regulates the entry of nutrients into the plant's interior by a selective process known as the Casparian strip. This strip is made up of suberin, which is a waterproof material, that prevents uncontrolled water and solute movement into the stele (vascular cylinder) and allows for selective ion uptake by endodermal cells. Therefore, option C is the correct choice. The root cap and cell wall of root hair do not play any role in regulating nutrient entry, whereas the plasma membrane of root hair is mainly responsible for water and mineral uptake.

In the Figure Below, the Line with the Arrowheads Indicates