Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
Transport in Living Things Chapter 25 Chapter 25.5 Transport System in Flowering Plants What did we learn? Movement of substances Passive process Diffusion Net movement of Gaseous molecules from a Carbon region of higher dioxide and exchange concentration oxygen insideto in of the a region lower leaves lungs concentration Osmosis Active process Active Transport Net movement of water molecules from a region of higher water of potential a Transport waterto into region of lower water potential roots permeable through a partially membrane Movement of molecules from a Transport of region of lower mineral salts concentration to a region higher intoofthe concentration roots with the use of energy Lesson Objectives At the end of the lesson, You should be able to: • State what the vascular bundle consists of • Describe the structure and function of xylem and phloem • Identify the position of xylem vessels and phloem in sections of the stem • relate the structure and functions of root hairs to their surface area, and to water and ion uptake Looking at the rose… • How do you turn a white flower into a blue one? • How does the coloured water travel up the stem to the flower? Vascular tissues 1. Xylem 2. Phloem Xylem tissue Structure • • composed of hollow, nonliving cells (continuous lumen) Lignified walls Function • • transports water and mineral salts from roots → stem → leaves provides mechanical support to plant Structure of Xylem QUESTION • How is the straw similar to the xylem? Phloem tissue Structure • Living cells Function • Transports manufactured food (sucrose and amino acids), usually from leaves → other parts of the plant Identifying a vascular bundle Identifying a vascular bundle in a dicotyledonous stem A vascular bundle cambium Transverse section of a stem Why do you think the xylem is positioned on the inside? How to distinguish xylem vessels from phloem in microscopic slides? Xylem vessels have • Thicker walls - due to lignified walls (either annular, spiral or pitted) to provide mechanical support to the plant • Larger lumen compared to phloem • Xylem vessels have a darker stain. Locate the xylem and phloem phloem xylem Leaf structure xylem phloem Transport of water Structure of root • Presence of Root hairs • Increased surface area Function of root • Absorb water and mineral salts from the surroundings • Water absorbed from the root enters the xylem Entry of water into the plant Thin film around particle = dilute solution of mineral salts Entry of water from soil Plasma membrane of root hair cell Sap in root hair Soil solution Strong solution of sugars and salts Dilute solution of mineral salts Low water potential H2O Higher water potential Osmosis Transport of water from root hair → xylem High water potential Low water potential Transport of mineral salts Transport of mineral salts Plasma membrane of root hair cell Soil solution Sap in root hair Mineral salts Mineral concentration low Mineral concentration high Diffusion Transport of mineral salts Qn: Can the root hair absorb ions if the concentration is higher in the root hair sap compared to the soil solution? Yes!!! Plasma membrane of root hair cell Soil solution Sap in root hair Mineral salts? Mineral concentration high Mineral concentration low Active transport Summary Plant Transport system Consists of Xylem Phloem transports Water containing dissolved mineral salts from the roots to the leaves where Water moves into the root hair cell via OSMOSIS Manufactured food substances (eg. sugars) from the leaves to the other parts of the plant Mineral salts move into the root hair cell via Diffusion OR ACTIVE TRANSPORT In the next lesson… We will be learning about • what is transpiration • what is translocation • MINI QUIZ!