Plants

Introduction

Plants - looking at germination, their structure and how they produce energy by photosynthesis

Kit List:

*Needs significant preparation in the days running up to the event*

Beansprouts in plastic containers, germinated prior to event, under different conditions (e.g. light/dark/water/no water/warm/cold)
Magnifying boxes
Small seedlings in pots (grown in light/dark/cold)
Microscope and slides showing section through plant leaves, stem, stomata, germinating seed

Explanation

Explanation:

Ideas to explain:
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For younger children

- Talk about what plants need to grow (water, warmth, light)
- Look at sequence of development i.e. seed, beansprout, small plant, larger plant, bigger plants flower and produce seeds (life cycle)
- Plants need light to produce energy - they don't eat like animals do (avoid using the term 'photosynthesis' with small children)
- Might want to look at plant cells in the microscope. They have a cell wall, so have a rigid shape, unlike animal cells. Green because of the pigment (chlorophyll) that they use to produce energy from light.

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Older children

- More detail on the different events happening in early plant development

- More detail on photosynthesis i.e. carbon dioxide converted into sugars, and oxygen is produced (the opposite idea to respiration)
- Gas exchange (Carbon dioxide for oxygen) happens through pores on the underside of leaves called stomata (you should be able to see these on one of the slides - see below).
- Light is absorbed by the green pigment (chlorophyll) in the leaves
- Plants have to transport sugars made in the leaves to other parts of the plant - this happens in the phloem (visible on slides)
- Water is transported from the roots in xylem (visible on slides - see below)

Risk Assessment

Risk Assessment:

RISKS
1)Electrical hazard (microscope), especially near sources of water.
2)Using thin glass slide could result in broken glass with risk of cuts
3)The light fitting under the microscope becomes hot, and could cause burns
4)Possible allergic reaction to seeds/plants/soil/leaf specimens
5)Injury from dropping seedling jars/plants
6)Possible injury from nail varnish when making slides

CONTROL MEASURES
1a)See separate electrical parts risk assessment
1b)Keep microscope away from water as it is not required for this experiment
2)If slides are broken, carefully collect/sweep up broken pieces, wrap in paper and dispose of carefully.
3)Warn children to be careful, turn of lamp when not in use, if it's getting hot put a cardboard shield around (but not touching) the lamp to prevent accidental contact.
4)Ask parents if child is allergic to the plant we are using
5)Have seedlings in plastic container, and use plastic plant pots
6)Demonstrator to make stomatal peels using nail varnish, if desired (pre-made slide should be sufficient not to have to do this)

IN CASE OF EMERGENCY
In case of accident or allergic reaction, call first aider.

This experiment contains mains electrical parts, see separate risk assessment.

CHaOS Science Roadshow

Demonstrator Section

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