First, study a wild oat seed with a hand lens. Record what you see. The long hair is called an awn. Then follow steps 1-6 below.
1. Cut a small hole in the centre of a circular piece of filter paper or paper towel.
2. Put the paper in a Petri dish lid and press a small piece of sticky putty in the centre.
3. Use a pencil to make a small hole in the sticky putty. Push a wild oat seed into the hole.
4. Add drops of water to the paper to make it thoroughly moist. Go on to Step 5 quickly.
5. Place a glass jar or beaker on the Petri dish lid to cover the sticky putty and seed. It needs to be moist.
6. Looking from above: rotate the Petri dish until the awn points to 12 o’clock and begin observations.
The wild oat awn is hydroscopic and moves rapidly (within a minute) in response to small humidity changes. This experiment shows one way of anchoring the seed and exposing it to different conditions so that the awn’s movements can be observed and measured.
Want to keep reading for free?
Register with Tes and you can read five free articles every month, plus you'll have access to our range of award-winning newsletters.
