1. Roots and Shoots Science - Year 3 Plants – Block 3P Session 5
Teaching PowerPoint
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2. What does our experiment tell us?
The coloured water has travelled up the stems to the leaves and flowers. But how?

3. We know the water started in the vase and travelled up the stem first and from there to the leaves and flowers.
But how does it travel?

4. Look at your sections of celery.
What do you notice?
There are coloured circles stained by the water.
What might these circles be?
They are the cut ends of long tubes that run up the length of the stem, a bit like tiny drinking straws.

5. If you look at the side of your stem of celery you will notice that there are ridges. These ridges are made by the tubes that run all the way up the stem.
The tubes are called xylem and it is their job to carry water up to the leaves and flowers. This is why you saw the leaves and flowers change colour.

6. Every stem, whether thick or thin, has tubes of xylem inside to transport water up through the plant.
Tree trunk
A tree makes a new ring of xylem each year which is why you can count the rings on a tree stump to find out how old it is.

7. What does water do in the leaves?
Remember we have already learnt that water is one of the ingredients a plant uses to make its food. Can you remember the other one?
It is a gas in the air called carbon dioxide

8. It is the leaves where food is made. The energy comes from …
sunlight

9. Flowers and stems need water too, to keep them healthy.
Flowers without water will quickly droop. This is called wilting

10. Does water ever leave the plant?
Yes, water escapes into the air through the tiny holes on the underside of the leaves. This water is in the form of vapour (a gas) which is invisible.

11. If you tie a plastic bag around some leaves on a plant, after a while it will fog up because of the escaping water vapour. This is rather like water vapour escaping from your lungs when you breathe out.

12. Our bean investigation has been running for about 4 weeks now
Our bean investigation has been running for about 4 weeks now. Each group has been controlling a different requirement to find out how it affects growth and health. The requirements are:
Water
Light
Warmth
Air
Soil
Space

13. Each group has been measuring the growth of 3 seedlings:
One with plenty of their requirement
One with a little of their requirement
One with none of their requirement
Each group has also been making notes for Zinnia on the health of their seedlings

14. Healthy seedlings have dark green leaves and thick strong stems

15. Unhealthy seedlings may have yellowing leaves
The leaves and stems may have shrivelled or wilted
The stems may have become too tall and weak (leggy).

16. Today, some people from each group will work on a report for Zinnia on how important their requirement is in the health and growth of plants. The report should include:
2. A graph to show the height of your 3 seedlings at the beginning, middle and the end of the investigation
1. A finished copy of your results table with all your measurements and notes. Today is the end of the investigation, so don’t forget to make one last set of observations.

17. Other people will do a report for Zinnia on what the investigation has taught us about how important each factor is. This will include labelled drawings of your 3 seedlings and an explanation of why they look different now.

18. Another group will do a report for Zinnia on the coloured water experiment and what it tells us about how water is transported in plants.

19. Let’s get started!