To recall: Roots are the part of plants which are underground. We can not see them but they play an important role for the plants. They absorb water and mineral salts, and then these absorbed materials are transported by the roots to the leaves.
Let us go through:
How the whole process of the absorption is carried out?
What are xylem and phloem vessels?
Roots adaptation:
Roots are the part of plant which is underground. Without them plants will not be able to survive.
For the absorption of water and mineral salts, roots have a special feature:
Root hairs:
Root hairs are tiny hair like structures on the roots, which give the roots a larger surface area to absorb maximum amount of water and mineral salts.
But what is the internal system of absorbing water and mineral salts, in the roots? We are getting to it!
After root hairs, roots have a substance called cortex. This part of root acts like a "storage house of the plants". In the cortex all the excess amount of food is saved. After this cortex, there is a layer of endodermis which separates the two vessels, Xylem and Phloem (which are enveloped inside the endodermis), from the cortex. Now, what are xylem and phloem vessel?
Xylem Vessel:
These vessels are very are very important. Now this vessel has a one way transporting path. It functions through out the plant. Xylem vessels take the absorbed water and mineral salts from the roots, to the stem and then to the leaves. The walls of xylem vessels are thick and have lignin in them which provides not only mechanical strength to the plant holding it upright, but also it strengths the walls of the vessels which prevents them from tearing or wearing off because of the high pressure flow of the water inside them.
Phloem Vessel:
Unlike xylem vessel, phloem has a two way transporting path. This vessel transports the products made by the plants during photosynthesis. These vessels take the glucose from the plants, to the stem, and then to the roots. Phloem has thin walls and it is not a strong vessel with walls having lignin because these vessels do not transport water.
Note: Xylem does not have any end walls, so that the water can easily flow through the vessel.
Summary.
.We discussed:
How roots absorb water and mineral salts?
What are xylem and phloem vessels?
*Pictures taken from google
Comments