These fingerlike processes are (unlike a root hair) made up of many cells.
The interior of the root hair is more or less filled with a fluid called cell sap.
The fluid in the root hair is denser than the soil water; hence the greater flow is toward the interior of the root hair.
When placed in water, it gives a very accurate picture of the root hair at work.
The cell sap, which partly fills the interior of the root hair, is a fluid of greater density than the water outside in the soil.
Examined under the microscope, these particles of soil seem to be cemented to the sticky surface of the root hair.
|root hair |
A hairlike outgrowth of a plant root that absorbs water and minerals from the soil. Root hairs are tubular extensions of the epidermis that greatly increase the surface area of the root. They are constantly dying off and being replaced by new ones as the root grows and extends itself into the soil.