RP10 -> Investigation into the effect of an environmental variable on the movement of an animal using either a choice chamber or a maze.

Describe how the effect of an environmental variable on the movement of

an animal (eg. woodlice) can be investigated using a choice chamber

1. Set up choice chamber (different compartments) to create different environmental conditions

○ Eg. humidity → add a drying agent to one side and damp filter paper to other

○ Eg. light → shine a light but cover one half with black card

2. Control other environmental conditions

○ Eg. if investigating humidity control light intensity with a dim even light above

3. Use a teaspoon to place 12 animals eg. woodlice on centre of mesh platform and cover with lid

4. After a set amount of time eg. 10 minutes record the number of animals in each section

5. Repeat after gently moving woodlice back to centre

The woodlice were left for 15 minutes

before their movement was recorded

when investigating the effect of humidity.

Explain why.

● Time to establish humidity / for substance to absorb

water / water from paper to evaporate

● Woodlice no longer affected by handling

● So that behaviour is typical of that humidity

Explain how you would ensure the safe and

ethical handling of animals.

● Safely - cover open wounds / wash hands with soap after

○ To minimise risk of infection

● Ethical - handle carefully / return to habitat ASAP

Explain why a mesh platform is used when

investigating the effect of humidity.

● To keep woodlice a safe distance from drying agent

Describe how the effect of an environmental variable on the movement of

an animal (eg. maggots) can be investigated using a maze

Mazes are used to investigate turning behaviour in response to different environmental conditions.

1. Change environment at one end of T shape eg. add food source

2. Place animal eg. maggot in stem of T

3. Record whether animal turns towards or away from food source

4. Repeat with a large number of maggots

○ Wipe / clean maze between trials

5. Repeat with food on other side of T

Explain why the same organism is not

used more than once.

● Reduces stress on maggots

● Prevents chance of learned behaviours

Explain why a clean petri dish / maze is

used each time.

● Animals may leave chemicals / scents

● Which influence behaviour of other animals

Explain which statistical test should be used to analyse results

● Chi-squared

● As data are categorical and comparing frequencies

● To see if there is a significant difference between observed and expected frequencies

○ Expected = equal numbers each side