Phloem

Definition

Phloem is the vascular tissue responsible for the transport of sugars and other metabolic products downward from the leaves. It plays a crucial role in the distribution of nutrients throughout seedless vascular plants.

5 Must Know Facts For Your Next Test

1. Phloem consists of sieve elements, companion cells, phloem fibers, and phloem parenchyma.
2. It transports organic nutrients, primarily sucrose, to various parts of the plant.
3. Phloem works alongside xylem to facilitate nutrient distribution and structural support within plants.
4. Unlike xylem, which only moves water one way (upward), phloem can transport substances in multiple directions.
5. In seedless vascular plants like ferns and horsetails, phloem is essential for survival as it distributes nutrients from photosynthetic tissues.

Review Questions

• What are the primary components of phloem?
• How does phloem differ from xylem in terms of nutrient transportation?
• Why is phloem important for seedless vascular plants?

Related terms

Xylem:

Vascular tissue responsible for transporting water and dissolved minerals upward from the roots.

Sieve Elements: Specialized cells in the phloem that facilitate the transport of sugars and other nutrients.

Companion Cells: Cells that assist sieve elements by managing their functions and supporting nutrient translocation.