#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 potential gradient from soil to air.

#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.

#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 eventually converge in the stele.

#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 these systems are rows of cells that make continuous tubes running the full length of the plant.

# 39 The need for transport systems in a multicellular organism

The transport system enables the rapid delivery of nutrients and O₂ to as well as the removal of metabolic waste products (including CO₂) from all cells of the body for survival.

#38.2 Transport in multicellular plants - Syllabus 2016 - 2018

7.1    Structure of transport tissues
7.2    Transport mechanisms

#38.1 Transport in multicellular plants - Syllabus 2015

• The need for, and functioning of, a transport system in multicellular plants