Own Story
Phototaxis is the tendency of an animal to move toward or away from the light. Those that move toward it are called positively phototaxic and those that move away from the light are called negatively phototaxic. What do you think woodlice are?
In groups of 2-3 put forward a proposal with an explanation. After that put it to the test by following the procedure below.
Experiment
Equipment
Petri dish
Filter paper
Black paper and sellotape
Paintbrush
Organisms
Woodlice
Procedure
1. Make an envelope out of the black paper that will cover one-half of the Petri dish and that can be easily slipped on and off.
2. Line the base of the Petri dish with two layers of filter paper and moisten it slightly
3. Using a paintbrush gently take 5-6 woodlice from their enclosure into the Petri dish and cover them with the lid. Now slide on the black paper envelope. Leave the dish alone for 10-15 minutes under normal room lighting.
4. After 10-15 minutes observe where the woodlice are located; are they in the dark or light region? ____________________________________________
5. Now move the black paper envelope so that it is covering the opposite side. Observe their location after another 10-15 minutes. Are they in the dark or light region? _________________________________________________
6. Do woodlice display positive or negative phototaxis? Was your prediction in the Own Story part of the exercise confirmed or rejected.
7. Can you maintain your explanation expressed in “Own Story” or would you like to propose another?
Expert
Jigsaw reading. See handout.
Critque
Do you agree or disagree with the experts? - explain
Evaluation
What have you learnt during this lesson?
