Which tissue acts as a filter on the water absorbed by root hairs in plants?

• A. Cortex
• B. Pericycle
• C. Endodermis
• D. Epidermis

Answer: (C)

Verified step by step guidance

1. Understand the role of each tissue mentioned in the question: The cortex stores nutrients, the pericycle is involved in root growth, the epidermis is the outermost layer of the root, and the endodermis regulates water and nutrient flow into the vascular system.
2. Recall that the endodermis contains a structure called the Casparian strip, which is a waxy barrier that forces water and dissolved substances to pass through the cell membranes of endodermal cells, acting as a selective filter.
3. Recognize that the Casparian strip ensures that harmful substances are filtered out before water and nutrients enter the vascular tissue (xylem and phloem).
4. Eliminate the other options: The cortex and pericycle do not have filtering functions, and the epidermis primarily protects the root and absorbs water but does not filter it.
5. Conclude that the endodermis is the tissue responsible for acting as a filter on the water absorbed by root hairs in plants.