Function Flashcards
Phloem: 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
Xylem: Function
Water and mineral transport from roots to aerial parts of the plant
Phloem: Movement
Bidirectional (Moves up or down the plant’s stem form “source to sink”)
Xylem: Movement
Unidirectional (Moves up the plant’s stem)
Phloem: Occurrence
Roots, stems and leaves. Transports sucrose to growth (roots and shoots) and storage regions of the plant (seeds fruit and swollen roots)
Xylem: Occurrence
Roots, stems and leaves.
Phloem: Additional functions
Forms vascular bundles with xylem
Xylem: Additional functions
Forms vascular bundles with phloem and gives mechanical strength to plant due to presence of lignin cells. The lignified secondary walls also makes the xylem waterproof and prevent it from collapsing under the pressure of water transpiration.
Phloem: Structure
Elongated, tubular shape with thin walled sieve tubes. The sieve tubes have pores at each end in the cross walls and mircotubules that extend between sieve elements allowing longitudinal flow of material
Xylem: Structure
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 forked protoxylem) + metaxylem (mature xylem) depending on pattern of lignin
Phloem: Elements
Sieve tubes, companion cells, phloem parenchyma (loosely packed resulting in intercullular spaces which allows gas exchange), bast fivers, intermediary cells
Xylem: Elements
Tracheids, vessel elements, xylem parenchyma (loosely packed resulting in intercullular spaces which allows gas exchange), xylem sclerenchyna
Phloem: Nature of tissue
Living tissues with little cytoplasm but no nucleus/ tonoplast
Xylem: Nature of tissue
Dead tissue at maturity so it is hollow with no cell contents
Phloem: Shape
Phloem is not star shaped
