The solution of salts from the soil absorbed by the trees which becomes a viscous solution due to loss of moisture and action of carbon dioxide is known as:
The Lifeblood of a Tree
A tree is a living organism that requires water and nutrients to grow. It has a vascular system to transport these essential elements from the roots up to the leaves and to distribute the food produced by photosynthesis back down to the rest of the tree. The fluid that circulates within this system is vital for the tree's life and growth.
📝 Detailed Analysis of the Options
(a) Pith
The pith is the small, central core of the tree trunk. It is a structural part of the wood, not the fluid that circulates within it.
(b) Cambium
The cambium is a very thin layer of living cells located between the sapwood and the bark. Its function is to create new wood cells (xylem) and bark cells (phloem). It is a layer of tissue, not the nutrient solution itself.
(c) Bark
The bark is the outermost protective layer of the tree. It shields the tree from damage but is not involved in the transport of the primary nutrient solution from the soil.
(d) Sap
This is the correct answer. Sap is the fluid that circulates through a tree's vascular system. It consists of water and mineral salts absorbed from the soil by the roots. This solution is transported upwards through the sapwood to the leaves. In the leaves, photosynthesis occurs: moisture is released, and carbon dioxide is absorbed, converting the raw sap into a more viscous, nutrient-rich solution (containing sugars). This enriched sap then descends, providing food for the tree's growth and forming a new layer of wood (the annual ring) under the bark.
📊 Components of a Tree Trunk
| Component | Description | Primary Function |
|---|---|---|
| Sap | Nutrient-rich fluid | Transports water and food for growth |
| Pith | Central core of the trunk | Structural (original stem) |
| Cambium | Thin layer between sapwood and bark | Cell production (growth) |
| Bark | Outermost layer | Protection |
💡 Study Tips
- Sap is the "Blood" of the Tree: Think of sap as the tree's circulatory fluid, carrying water and nutrients just like blood does in an animal.
- Sapwood Carries Sap: The name "sapwood" itself tells you its function: it's the part of the wood that carries the sap.
- Distinguish Fluid from Tissue: Remember that sap is the liquid, while pith, cambium, and bark are solid tissues or layers of the tree.