Correct Option
The correct option is Xylem.
Explanation
Vascular plants possess a specialized transport system consisting of two complex tissues: xylem and phloem. These tissues are responsible for the translocation of water, minerals, and organic nutrients throughout the plant body.
Detailed Analysis
- Xylem: This tissue is responsible for the transport of water and dissolved minerals absorbed by the roots to the stems and leaves. The flow of materials in the xylem is strictly unidirectional (from roots upwards to the aerial parts). This upward movement is primarily driven by transpirational pull and root pressure.
- Phloem: This tissue transports organic food materials (photosynthates like sucrose) from the leaves (source) to other parts of the plant (sink). The transport in phloem is bidirectional (both upward and downward) depending on the metabolic needs of the plant.
- Cambium: This is a lateral meristematic tissue responsible for secondary growth, which increases the girth or thickness of the stem and roots. It is not involved in the vertical transport of water or minerals.
- Cortex: This is a layer of ground tissue located between the epidermis and the vascular cylinder. Its primary functions include the storage of food and the transport of water from root hairs to the vascular cylinder, but it is not the primary vascular tissue for long-distance transport.
Key Takeaway
Xylem facilitates the unidirectional transport of water and minerals, whereas phloem is responsible for the bidirectional translocation of organic nutrients.