Biology
- Phloem & Xylem
Are Phloem and Xylem Similar? What are the Differences? Similarities: Phloem and xylem are tissues in a plant that transport food and water. Both are vascular tissues and when they work together to effectively transport food, water and minerals they form...
- #42 Summary Of Transport In Multicellular Plants
1. Multicellular organisms with small surface area to volume ratios need transport systems. 2. Water and mineral salts are transported through a plant in xylem vessels. Movement of water is a passive process in which the water moves down a water...
- #41 Transport In Phloem
The movement of substances in phloem tissue is called translocation. The main substances that are moved are sucrose and amino acids, which are in solution in water. These substances have been made by the plant and are called assimilates. Phloem...
- #40 Movement Of Water And Minerals In The Xylem
Most plants secure the water and minerals they need from their roots. The path taken is: soil -> roots -> stems -> leaves. The minerals (e.g., K+, Ca2+) travel dissolved in the water. Water and minerals enter the root by separate paths which...
- #39 Structure Of Transport Tissues In Plants
Plants have 2 transport systems: xylem: transports water and inorganic ions from the roots to the leaves.phloem: transports food made in the plant (sucrose and amino acids) from the leaves to the rest of the plant. Both of...
Biology
#38.1 Transport in multicellular plants - Syllabus 2015
? The need for, and functioning of, a transport system in multicellular plants
Learning Outcomes
Candidates should be able to:
(a) explain the need for transport systems in multicellular plants and animals in terms of size and surface area to volume ratios;
(b) define the term transpiration (see section 5) and explain that it is an inevitable consequence of gas
exchange in plants;
(c) [PA] describe how to investigate experimentally the factors that affect transpiration rate;
(d) [PA] describe the distribution of xylem and phloem tissue in roots, stems and leaves of dicotyledonous plants;
(e) [PA] describe the structure of xylem vessel elements, phloem sieve tube elements and companion cells and be able to recognise these using the light microscope;
(f) relate the structure of xylem vessel elements, phloem sieve tube elements and companion cells to their functions;
(g) explain the movement of water between plant cells, and between them and their environment, in terms of water potential (no calculations involving water potential will be set);
(h) describe the pathways and explain the mechanisms by which water is transported from soil to xylem and from roots to leaves (includes reference to the symplast/symplastic pathway and apoplast/apoplastic pathway);
(i) outline the roles of nitrate ions and of magnesium ions in plants;
(j) [PA] describe how the leaves of xerophytic plants are adapted to reduce water loss by transpiration;
(k) explain translocation as an energy-requiring process transporting assimilates, especially sucrose,
between the leaves (sources) and other parts of the plant (sinks);
(l) explain the translocation of sucrose using the mass flow hypothesis;
Learning Outcomes
Candidates should be able to:
(a) explain the need for transport systems in multicellular plants and animals in terms of size and surface area to volume ratios;
(b) define the term transpiration (see section 5) and explain that it is an inevitable consequence of gas
exchange in plants;
(c) [PA] describe how to investigate experimentally the factors that affect transpiration rate;
(d) [PA] describe the distribution of xylem and phloem tissue in roots, stems and leaves of dicotyledonous plants;
(e) [PA] describe the structure of xylem vessel elements, phloem sieve tube elements and companion cells and be able to recognise these using the light microscope;
(f) relate the structure of xylem vessel elements, phloem sieve tube elements and companion cells to their functions;
(g) explain the movement of water between plant cells, and between them and their environment, in terms of water potential (no calculations involving water potential will be set);
(h) describe the pathways and explain the mechanisms by which water is transported from soil to xylem and from roots to leaves (includes reference to the symplast/symplastic pathway and apoplast/apoplastic pathway);
(i) outline the roles of nitrate ions and of magnesium ions in plants;
(j) [PA] describe how the leaves of xerophytic plants are adapted to reduce water loss by transpiration;
(k) explain translocation as an energy-requiring process transporting assimilates, especially sucrose,
between the leaves (sources) and other parts of the plant (sinks);
(l) explain the translocation of sucrose using the mass flow hypothesis;
- Phloem & Xylem
Are Phloem and Xylem Similar? What are the Differences? Similarities: Phloem and xylem are tissues in a plant that transport food and water. Both are vascular tissues and when they work together to effectively transport food, water and minerals they form...
- #42 Summary Of Transport In Multicellular Plants
1. Multicellular organisms with small surface area to volume ratios need transport systems. 2. Water and mineral salts are transported through a plant in xylem vessels. Movement of water is a passive process in which the water moves down a water...
- #41 Transport In Phloem
The movement of substances in phloem tissue is called translocation. The main substances that are moved are sucrose and amino acids, which are in solution in water. These substances have been made by the plant and are called assimilates. Phloem...
- #40 Movement Of Water And Minerals In The Xylem
Most plants secure the water and minerals they need from their roots. The path taken is: soil -> roots -> stems -> leaves. The minerals (e.g., K+, Ca2+) travel dissolved in the water. Water and minerals enter the root by separate paths which...
- #39 Structure Of Transport Tissues In Plants
Plants have 2 transport systems: xylem: transports water and inorganic ions from the roots to the leaves.phloem: transports food made in the plant (sucrose and amino acids) from the leaves to the rest of the plant. Both of...