7. Why do you think that root hairs are produced only on the parts of the root system that stopped growing?

The function of root hairs is to help the plant absorb water and nutrients. Root hairs are part of the root system of the plant and their job is to increase the surface area of the roots, allowing them to take in more nutrients than if the roots were smooth.

They are found only in the zone of maturation, and not the zone of elongation, possibly because any root hairs that arise are sheared off as the root elongates and moves through the soil. Root hairs grow quickly, at least 1μm/min, making them particularly useful for research on cell expansion.

it would be c. xylem.