RP10 - Investigation Into The Effect Of An Environmental Variable On The Movement Of An Animal Using Either A Choice Chamber Or Maze

Question 1

Describe how the fact of an an environmental variable on the movement of an animal (e.g. Woodlice) can be investigated using a choice chamber (5)

Answer 1

1) Set up a choice chamber (different compartments) to create different environmental conditions
- E.g. humidity -> add a drying agent to one side and damp filter paper to the other
- E.g. light -> shine a light but cover one half with black card

2) Control other environmental conditions
- E.g. if investigating humidity control light intensity with a dim even light above

3) Use a teaspoon to place a set number of animals e.g. 12 Woodlice on centre of mesh platform and cover with lid

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

5) Repeat after gently moving Woodlice back to centre

Question 2

The Woodlice were left for 15 minutes before their movement was recorded when investigating the effect of humidity. Explain why (3)

Answer 2

1) Time to establish humidity / for substance to absorb water / water from paper to evaporate

2) Woodlice no longer affected by handling

3) So that behaviour is typical of that humidity

Question 3

Explain how you would ensure the safe and ethical handling of animals (2)

Answer 3

1) Safely -> cover open wounds / wash hands with soap after (to minimise risk of infection)

2) Ethical -> Handle carefully / return to habitat ASAP

Question 4

Explain why a mesh platform is used when investigating the effect of humidity (1)

Answer 4

To keep Woodlice a safe distance away from drying agent

Question 5

Why would a maze be used in this experiment?

Answer 5

To investigate turning behaviour in response to different environmental conditions

Question 6

Describe how the fact of an environmental variable on the movement of an animal (e.g. maggots) can be investigated using a maze (5)

Answer 6

1) Change environment at one end of T shape e.g. add food source

2) Place animal e.g. 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 and clean maze before trials

5) Repeat with food on other side of T

Question 7

Explain why the same organism is not used more than once (2)

Answer 7

1) Reduces stress on maggots

2) Prevents chance of learned behaviours

Question 8

Explain why a clean Petri dish / maze is used each time (2)

Answer 8

1) Animals may leave chemicals / scents

2) Which influence behaviour of other animals

Question 9

Explain which statistical test should be used to analyse results (3)

Answer 9

1) Chi-squared

2) As data are categorical and comparing frequencies

3) To see if there is a significant difference between observed and expected frequencies
- Expected = equal numbers each side