Imagine looking up at a tall rainforest tree and thinking about some serious problems they may face? Difference between xylem and phloem. Where is photosynthesis occurring in these vast trees? What raw materials are needed for plants? How are they even distributed so well in the plant from roots till leaves?
Having the basic knowledge of plants, it is easy to tell that water, carbon dioxide, sunlight, and organic molecules like sugar and starch are needed for photosynthesis. Sunlight is obtained from the sun. Carbon dioxide from the air and others from the ground. But how do the leaves on top of plants get all this from below the ground?
In this article, you will learn about two complex vascular tissues in plants responsible for this transportation. Xylem and Phloem are responsible for transporting materials in these plants.
What is Xylem?
Xylem is a vascular tissue that helps in the formation of the woody structure of a plant. It provides mechanical support within the plant. It transports water and dissolved substances from the roots to the leaves.
What is Phloem?
The phloem conducts the transportation of food such as sucrose and amino acids from the green parts of the plants to other parts of the plants.
Significant differences between xylem and phloem.
1. Definition
Xylem is derived from the Greek word “Xylon,” which means wood. Xylem is known as a complex tissue of a plant that plays the role of transportation in plants. It transports water and soluble minerals from the roots to the leaves.
Phloem is derived from the Greek word “phloios,” which means bark. The Phloem transports food and other organic material from green parts of plants to where it’s required. Phloem is known as living tissue.
2. Location
Xylem is located deep inside the plant between the vascular bundles. It forms the woody part of the tree or plant.
Phloem is located on the exterior side of the vascular bundle. It forms most of the part of the bark.
3. Cells
Xylem consists of dead cells.
Phloem made up of living cells.
4. How many tissues do they have?
Xylem made up of xylem vessels, fiber, and tracheids.
Phloem consists of fibers, sieve tube, sieve cells, phloem parenchyma, and companion cells.
5. What does it consist of?
Xylem consists of dead cells. The only living cell known in the xylem is the parenchyma.
Phloem made up of living cells—the only dead cells in phloem known as fibers.
6. What is found in it?
Xylem found in leaves, roots, and stems.
Phloem found in stems, leaves, roots, fruits, and seeds.
7. What is its movement?
The movement of the xylem considers unidirectional. This means the water and soluble minerals will move only from roots to the leaves.
The movement of phloem considers bidirectional. This means that food and minerals can travel up and down the plant.
8. What is its central role?
Xylem gives mechanical support to the plant. Along with it, Xylem tissue transports water and minerals from the roots.
Phloem does not give any mechanical support to a plant. The Phloem tissue transports food prepared by green parts of the plant to other parts of the plant.
9. What other features does it have?
The mature xylem is dead tissue. It mainly becomes the bulky part of the plant. The conducting cells of the Xylem are mostly dead. Apart from its primary role, the Xylem is also responsible for recovering the water in plants lost through transpiration and photosynthesis.
Mature phloem tissue is a living cell without any nucleus. It is not a significant part of a plant’s body. The conducting cells of phloem are alive.
How does the water move against gravity?
There must be one big query in your mind, and that is the most intriguing of all. How do water and the mineral salts dissolved in it get from the roots to the leaves of the plants?
It knows as root pressure and capillarity in water transport. The living cells around xylem vessels in root use active transport to pump up ions into the vessels. This lowers the water potential in the xylem vessels. Water, therefore, passes from the living cells into the xylem vessels by osmosis and flows upwards. This called root pressure.
Root pressure alone is not sufficient to bring water up to the leaves in tall trees. Other factors which are also at work are capillary action and transpiration pull. Water tends to move up inside fine capillary tubes by capillary action. Since the xylem vessels in the plant are very narrow capillary tubes, capillary action helps move water up the vessels.
Capillary action plays a part in the upward movement of water in small plants. The greater force that causes water to rise to the leaves of a tall tree known as transpiration. It is The loss of water vapors from the aerial parts of a plant, primarily through the stomata of the leaves.
Do they have any similarities?
After looking at a variety of differences between xylem and phloem, one can question the similarity of both. Yes, there are few ways in which xylem and phloem are quite the same.
- The cell wall of both the xylem and phloem made up of cellulose.
- Chloroplast exists in both the xylem and phloem.
- The vascular tissue in both of them eases the transport of material in a plant.
- Parenchymatous cells exist in both the xylem and phloem.
Conclusion
Xylem and phloem composed of vascular bundles are critical and complex tissue. You have seen significant differences between xylem and phloem here. Nonetheless, you also came to know about few similarities in them. Xylem and phloem both works as a transportation systems in plants. However, the xylem is only responsible for the transportation of water and soluble materials in a plant.
On the other hand, phloem transports food and organic material to its plant. The vascular tissues in the xylem and phloem play a significant role in the growth of a plant. So, the plants which the most highly evolved have a complex system.
Also read: Difference between prokaryotic and eukaryotic cell
