Question

Briefly describe phloem constituentswith respect to size,location,structure and functions.

Answer 1

S.NO	Phloem Tissue	Phloem Tissue
1.	Occurrence or location	Found in root, leaves and stem. It occurs on the outer side of the vascular bundle.
2.	Structure	Thin walled tubular seive tubes that have perforations at the cross walls accompanied by companion cells, phloem parenchyma that are loosely packed, Phloem fibers vary in length from less than 0.04 in. or 1 mm in some plants to 20 in. or 50 cm). The secondary walls are thick and typically have simple pits that may or may not be lignified.
3.	Functions	Transport of sucrose from source to sink and vice versa.