Review children's knowledge of plants as living things by asking them a variety of questions, e.g
What plants can you see from the window?
Are they all living?
How do you know?
How do we help plants grow well?
Why do we need plants to grow well?
Check the pupils knowledge of Parts of a Plant, either test their knowledge using real examples or ask them to draw and label a typical plant or one of their choice.
Perhaps work in small groups to match up parts of a plant with their names and purposes.
Examine the end of the flower stems or celery with magnifiers. The stems are formed of hollow cells (xylem) which draw water from the soil.
Working in small groups add food colouring to water in a beaker or bottle and mark the level of that water on the side. Can pupils predict what will happen?
Place the flower or celery stems in the beaker or bottle and leave for an agreed amount of time.
What has happened to a) the level of the water in the bottle or beaker or b) to the stem and flowers?
Contnue to examine the stems at agreed intervals and record the results by observational drawings or photographs.
Examine how coloured water has been drawn up by the xylem by cutting the stems into cross sections. Different groups can present their findings about water transportation in plants to the rest of the class.