Practical 10 Flashcards
Required practical 10 - Describe how the effect of an environmental variable on the movement of
an animal (eg. woodlice) can be investigated using a choice chamber
- 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 - Control other environmental conditions
○ Eg. if investigating humidity control light intensity with a dim even light above - Use a teaspoon to place 12 animals eg. woodlice on centre of mesh platform and cover with lid
- After a set amount of time eg. 10 minutes record the number of animals in each section
- Repeat after gently moving woodlice back to centre
Practical 10 - 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
Practical 10- 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
Practical 10- 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
Practical 10- (maggots) Explain why the same organism is not used more than once.
reduces stress on maggots
• Prevents chance of learned behaviours
Practical 10-(maggots) Explain why a clean petri dish / maze is used each time.
• Animals may leave chemicals / scents
• Which influence behaviour of other animals
Practical 10-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
