What am I Diagram a Diagram b Diagram

What am I? ? ? Diagram a Diagram b Diagram c

Module 2 Exchange and transport 1. 2. 13 Transport in plants-

Learning Objectives Success Criteria • Describe the structure and • Define xylem and phloem (Grade D – C) function of xylem vessels, sieve tube elements and • Describe the structure and companion cells function of a xylem and phloem (Grade C –B) • Compare the structure of xylem and phloem, linking it to their importance (Grade B – A)

Starter Using knowledge from KS 4 Write a definition of xylem and phloem Share defintions and add to them Xylem – plant transport tissue that carries water from roots to the rest of the plant. It consists of hollow columns of dead cells lined end-end and reinforced with lignin. Providing support. • Phloem – plant transport tissue that carries products of photosynthesis to the rest of the plant. It consists of sieve elements and companion cells • Define xylem and phloem • • (Grade D – C)

Transporting water and nutrients

How is xylem adapted for transportation? Water and minerals travel in xylem vessels. Xylem vessels transport water and minerals from the roots to the shoot and leaves. This transport only occurs in one direction.

How is xylem adapted for transportation? Xylem vessels have thick cellulose cell walls, strengthened & waterproofed by lignin. The inside of the cell is hollow. Xylem vessels are dead cells. In some places lignification is incomplete, there are pores in the wall called pits/bordered pits that allow water to leave one vessel to the next

How is phloem adapted to transportation? Phloem is made of columns of living cells. They transport food, in the form of sugars. Sugars are carried from the leaves to the growing and storage parts of the plants. This movement takes place in both directions.

How is phloem adapted to transportation? Phloem cells consist of sieve tubes. Cells are joined by small holes in the cell wall at the end of each cell, forming a continuous system. The end cell walls are called sieve plates. Companion cells carry out living functions for both themselves and sieve cells. Providing energy fro the active transport of sugars

Task • In groups create a model of a xylem and a phloem • Create an information sheet on xylem and phloem • Describe the structure and function of a xylem and phloem (Grade C –B) • Compare the structure of xylem and phloem, linking it to their importance (Grade B – A)