Session 1 · VOICE: Investigate
Pond drop safari and soil life
- 5 minSafety briefing: gloves, no touching faces, wash hands, all pond water goes back outside or into the garden, not down a drain.
- 25 minPond drop safari: groups search three drops each, sketch every organism, and note whether it is green (makes its own food) or not (must eat).
- 15 minSoil station: tease apart compost or leaf litter with a hand lens and look for white fungal threads, then set up a sealed mud column to grow soil microbes over the next weeks.
- 5 minShare the strangest organism found. Add it to the class 'hidden world' field guide.
Session 2 · VOICE: Investigate
The diffusion race
- 10 minDrop food colouring into cold water and warm water at the same moment. Time how long until the colour is spread evenly.
- 20 minWhy are cells so small? Put potato or jelly cubes of three sizes into coloured water. After 15 minutes cut them open and measure how far the colour moved in.
- 15 minExplain with particles: particles spread from where there are more to where there are fewer. Oxygen and carbon dioxide move into and out of cells this way.
- 5 minPredict: would a cell the size of a football work? Write why or why not.
Getting started
Use the pond ID sheet with pictures of common pond organisms and a 'green or not green' column.
Stretch
Work out the surface area and volume of each cube and show why a small cube has more surface for its size.
Checkpoint
Each group has drawn at least three different single-celled organisms and has timed diffusion results for warm and cold water.
Activities for this week
- Pond drop safari: What lives in a single drop of pond water?
- The diffusion race: How do substances move into and out of cells, and why are cells so small?
- Grow a mud column: What soil microbes grow when we give them food and light?
Useful this week
- Observing soil microbes ↗ Safe ways to see the invisible life in soil.
- Diffusion ↗ Watch particles spread out and change the temperature to see what happens.