Causes of Animal Movement (AQA A Level Biology): Revision Note

Required practical: investigating environmental factors that cause animal movement

• Environmental factors that influence animal movement can be investigated using equipment such as a:

  • choice chamber

  • maze

Investigating the effect of moisture on movement in woodlice

Apparatus

• Choice chamber

• Distilled water

• Drying agent, e.g. anhydrous calcium chloride

• Gauze platform

• Woodlice

• Soft paintbrush

Method

1. Set up the choice chamber so that it has two distinct sections:

   • one side with moist conditions, e.g. by adding distilled water to the base of the chamber

   • one side kept dry, e.g. by adding drying agent to the base of the chamber

2. Insert a gauze platform into the choice chambers

   • This keeps the woodlice at a safe distance from the water and drying agent

3. Place a group of 10 woodlice in the centre of the chamber, where both conditions are accessible

   • The woodlice can be placed into the chamber using the hole in the lid

   • Woodlice should be handled carefully so that they are not harmed

4. Start a timer and allow the woodlice to move freely for 10 minutes

5. At the end of the time, record the number of woodlice in each section of the chamber

6. Repeat the experiment at least twice more

   • A soft paintbrush can be used to gently move the woodlice back to the centre of the chamber between each repeat

7. Calculate the mean number of woodlice found in the moist and dry sides across all trials

   • Woodlice should be returned to the location from which they were collected at the end of the experiment

Control variables

• Control other relevant environmental variables, e.g.

  • light intensity

  • temperature

  • surface texture

• Use the same individual woodlice in each trial, and select woodlice from the same environment, so that differences between individuals don't affect results

• Clean the chamber carefully before use so that chemical traces don't affect results

• Minimise handling time so that stress doesn't affect woodlouse behaviour

Variations

• Observe the woodlice during the experiment and record observations of their movement to determine whether they are showing a taxis or kinesis response

• A variation on this experiment could involve covering half of the choice chamber so that the independent variable is light:

• A paper maze can be used to investigate turning behaviour in woodlice under different conditions