How does water enter the root hairs?
The movement’s by way of osmosis. How it’s done is by passage through the root hair cell wall, ka the membrane. Why it’s done is for balance. For nature abhors a vacuum, and an imbalance. And the water contents, and therefore the concentrations, aren’t the same on either side of the root hair cell wall. So water moves from less of a concentrate, such as the soil moisture level of just mineral salts; to more of a concentrate, such as the root hair cell sap of sugars, salts, and amino acids. What happens is progressive diluting of the more concentrated cell sap in each of the progressive series of cell walls through which the less concentrated soil water passes. Once water gets to the root’s meeting with the stem, though, it moves by suction upwards. Transpiration’s what gets the suction started. For water’s released into the environment through stomata, which are pores on the undersides of leaves. This above-ground release sucks the below-ground water of the roots up through the stems a