Why are root hairs necessary?

Question

this is on a plant not my head

Answer 1

Root hairs, the rhizoids of many vascular plants, are tubular outgrowths of trichoblasts, the hair-forming cells on the epidermis of a plant root. That is, root hairs are lateral extensions of a single cell and only rarely branched. Just prior to the root hair development, there is a point of elevated phosphorylase activity.

The ability of the root epidermis to absorb water from the surrounding soil is the same with or without root hairs, but the root hairs enlarge and extend the water absorbing surface.

Answer 2

Root hairs are unicellular outgrowths of the root epidermis. More often than not, it is confused with branch roots or lateral roots because both are arranged laterally. Anyway, so as to differentiate the two, branch roots arise from the pericycle and are multicellular, compared to root hairs which are merely epidermal outgrowths and are unicellular.

Root hairs are also called trichomes. Actually, they are just one of the examples of many trichomes. But so as not to confuse, we use the term trichome more often for the outgrowths of the stem epidermis.

The most common function of root hairs is that it has seemed for most scientists to play a role absorption by increasing the absorptive surface area of roots. Nevertheless, it still plays a role in absorption of water and nutrients from the soil.

Still, remember this:

The ability of the root epidermis to absorb water from the surrounding soil is the same with or without root hairs, but the root hairs enlarge and extend the water absorbing surface.

from: http://en.wikipedia.org/wiki/Trichome

Aside from the observation of scientists done on root hairs, I myself have observed the necessity of root hairs as one who studies Botany (this is not a joke):

Root hairs distinguish whether a transverse section is that of a stem or a root. Obviously, root hairs can only be found on roots.

Yes, aside from that, because of the presence of root hairs, it is easier to determine a taproot root system and a fibrout root system. Because you look at the root hairs; if you find that they are not on a primary root then it is a taproot; they grow instead on secondary or if not, then on tertiary roots. We find it is fibrous if all the individual slender roots have root hairs.

Therefore, aided by the presence of root hairs, a Botany student can easily determine whether a plant is a monocot or a dicot.


Here are pictures that might help:

longitudinal section:
http://www.esu.edu/~milewski/intro_biol_two/lab_5_roots_leaves/images/zea_root_hairs_ls.jpg

transverse section:
http://www.esu.edu/~milewski/intro_biol_two/lab_5_roots_leaves/images/zea_root_hairs_ls.jpg

general view:
http://www.treedictionary.com/DICT2003/IMAGES/ROOT%20HAIRS-1.jpg

Hope it helps. :-)

Answer 3

I'm going to try to keep my answer as simple as possible.
The outer or epidermal cells of a root absorb water and minerals from the soil.Many of these cells form extensions called
root hairs which probe the soil taking in water and minerals

Answer 4

Root hairs reach out into the soil giving the root more surface area to absorb water - letting the root touch more soil and water to absorb.

Answer 5

Roots hairs are made up of cellulose and are semi-permeable ,thus allowing the mud/soil water to enter and nourish the plant.

Answer 6

They act as pathways for absorbing water and nutrients from the soil

Answer 7

so that your hair can grow.
its like grass.
why does grass have roots