Transport in Plants

Chapter 14

Transport in a plant

• Plants have a transport system.

• Xylem vessels carry water (and minerals ) from the roots to the leaves of the plant.

• Phloem tubes carry food (made in the leaves) all around the plant.

To show the absorbtion of water by roots

Transpiration

• What is Transpiration?

• Transpiration is the loss of water from the leaves of a plant.

• Water is lost through the stomata. These are tiny pores on the undersurface of the leaf.

The Transpiration stream

The flow of water

from the roots to

the leaves is called

the transpiration

stream.

Functions of Transpiration

The functions of transpiration are:

1.To carry water to the leaves for photosynthesis

2.To carry minerals from the roots to the leaves

3.To cool the plant.

Factors affecting transpiration

Transpiration is highest in:

Bright sunlight

a gentle breeze

low humidity

and good availability of soil water

To show the absorption of water by roots

• Set up apparatus as shown.• Test tube A is a control.

• Record the level of water in each test tube after a week.

• Result

Water

Oil

To Demonstrate TranspirationApparatus:

Potted plant, plastic bag,

Elastic band, Blue Cobalt chloride paper

Method:

1. Set up apparatus as shown in diagram

2. Leave in a warm place for 3-4 hours.

3. Test the droplets of colourless liquid with blue cobalt chloride paper.

Result

The blue cobalt chloride paper will turn pink.

This shows that water vapour is released from a plant during respiration.