Question

Differentiate xylem and phloem

Answer 1

Phloem and xylem are complex tissues that perform transportation of food and water in a plant. They are the vascular tissues of the plant and together form vascular bundles. They work together as a unit to bring about effective transportation of food, nutrients, mineralsand water.

Comparison chart Phloem versus Xylem comparison chart Phloem Xylem

Function
Transportation of food and nutrients such as sugar and amino acids from leaves to storage organs and growing parts of plant. This movement of substances is called translocation.	Water and mineral transport from roots to aerial parts of the plant.
Movement
Bidirectional (Moves up or down the plant's stem from "source to sink")	Unidirectional (Moves up the plant's stem)
Occurrence
Roots, stems and leaves. transports sucrose to growth (roots and shoots) and storage regions of the plant (seeds fruit and swollen roots)	Roots, stems and leaves
Additional Functions
Forms vascular bundles with xylem	Forms vascular bundles with phloem and gives mechanical strength to plant due to presence of lignin cells. The lignified secondary wall also makes the xylem waterproof and prevent it from collapsing under the pressure of water transpiration
Structure
Elongated, tubular shape with thin walled sieve tubes. The sieve tubes have pores at each end in the cross walls and microtubules that extend between sieve elements allowing longitudinal flow of material.	Tubular shape with no cross walls which allows a continuous column of water + facilitates more rapid transport within the xylem vessels. There are two types - protoxylem (first formed xylem) + metaxylem (mature xylem) depending on pattern of lignin.
Elements
Sieve tubes, companion cells, phloem parenchyma (loosely packed resulting in intercellular spaces which allows gas exchange), bast fibers, intermediary cells,	Tracheids, vessel elements, xylem parenchyma (loosely packed resulting in intercellular spaces which allows gas exchange), xylem sclerenchyma
Nature of tissue
Living tissue with little cytoplasm but no nucleus/tonoplast.	Dead tissue at maturity so it is hollow with no cell contents
Shape
Phloem is not star shaped.	Xylem is star shaped.
Location in vascular bundle
Phloem occur on outer side of the vascular bundle.	xylem occupy the center of the vascular bundle.