Transport in plants

Transport systems

There are two transport systems in a plant.

One that transports water and minerals from root to all other parts. These vessels are called ………….

Another vessels transport sugars (sucrose) and amino acids made in leaves to all other plant parts. These are called phloem vessels.

Xylem vessels

Are long , hollow, continuous tubes that carry water and dissolved minerals from the root up to all parts of the plant.

Contain a tough substance called lignin that lines the walls to provide support.

Phloem vessels

Phloem tubes are living cells with end tubes with pores (sieve plate).

All cell contents have disappeared except the cytoplasm

The phloem cells have companion cells near them.

Phloem cells transport sucrose and amino acids from where they are made to where they are used or stored.

Dicot stem Dicot root

Stem structure

Root structure

How water moves into the plant.

Transpiration

It is the loss of water vapour out of leaves (and stems) through stomata by diffusion.

Experiments

1. measure water uptake by plant shoots.

2. Show that transpiration takes place in shoots.

3. Show there are more stomata on the lower side of a leaf.

Potometer

A potometer measures the rate of water uptake.

The distance moved by the air bubble can be measured every minute to show the rate of water uptake.

The air bubble can be moved back to the start position by…………………….

Water is not only lost by transpiration in the leaves it is also used by the leaves during ………….….

Put your thinking caps on!

Predict what would happen to the rate of water uptake if the temperature increases.

When the wind speed increases?When light intensity increases?When humidity increases?

Transpiration is affected by

Weather condition Rate of transpiration Why?

Windy Speeds up transpiration

Moist air around the

leaf is blown away

Humid Slows down transpiration

Air around the leaf is

already full of

moisture

Warm Speeds up transpiration

Evaporation occurs faster

Light Speeds up transpiration The stomata opens

Translocation

Is moving food (sucrose and amino acids) from the sources (leaf, root) to sinks (developing flowers/fruits, storage organs) through the phloem vessels.