Why do root hair need to be replaced daily?
Answers
Root hair cells can survive for 2 to 3 weeks and then die off, at the same time new root hair cells are continually being formed at the tip of the root. This way, the root hair coverage stays the same. When a new root hair cell grows, it excretes a poison so that the other cells in close proximity to it are unable to grow one of these hairs. This ensures equal and efficient distribution of the actual hairs on these cells.
The act of re-potting or transplanting a plant can result in root hair cells being pulled off, perhaps to a significant extent, and such plants may therefore wilt for some time as a result
A couple reasons come to mind.* The purpose of root hairs is absorbtion. If you consider multiple cells along the length of the hair, additional cell walls and plasma membranes would somewhat impede the movement of nutrients. More importantly, the absorbtion is a function of the surface area of the hair.