Question

The root cap is not used in absorption of water due to
A. Presence of root hairs
B. Absence of root hairs
C. Its presence in elongation zone
D. None of the above

Answer 1

The root cap is a type of tissue at the tip of a plant root.
-It is also known as calyptra.
-Root caps contain statocytes which are involved in gravity perception in plants.

Complete step by step answer:
-A root hair, or absorbent hair is the rhizoid of a vascular plant.
-It is a tubular outgrowth of a trichoblast, a hair-forming cell on the epidermis of a plant root.
-Root hair is found only in the zone of maturation, and not the zone of elongation.
-It is possible because any root hairs that arise are sheared off as the root elongates and moves through the soil.
-Plants absorb water from the soil by the process of osmosis.
-Root hair cells are adapted for this by having a large surface area to speed up osmosis.
-Increasing root surface area aids plants to be more efficient in absorbing nutrients and establishing relationships with microbes.
-Water passes from the soil water to the root hair cell’s cytoplasm by osmosis.
-This happens because the soil water has a higher water potential than the root hair cell cytoplasm.
-The function of root hairs is to collect water and mineral nutrients that are present in the soil and take this solution up through the roots to the rest of the plant.
-Root caps have no root hairs.

So, the answer is B. Absence of root hairs

Additional information:
Root hair cells are long and it helps to penetrate between soil particles, and prevent harmful bacterial organisms from entering the plant through the xylem vessels.
Another adaptation that plants have is root hair cells have a large permanent vacuole.

Note:
The purpose of the root cap is to enable downward growth of the root, with the root cap covering the sensitive tissue in the root.
The root cap enables geo perception or gravitropism which allows the plant to grow downwards (with gravity) or upwards (against gravity).