Specification location: AQA GCSE Biology Paper 2, Section 4.5 - Homeostasis and response
Summary of method: Individual 1 holds a ruler; the end of the ruler is placed between the fingers of an Individual 2 (at the 0cm mark). Individual 1 then drops the ruler at a random moment and Individual 2 attempts to catch it between their fingers. The point at which they catch it (the length of the drop) is determined by reading the length from the ruler where Individual 2’s fingers caught it. This distance is then converted on a look-up table to a reaction time. Individual 1 repeats this nine more times. Individual 1 and 2 swap roles and the entire investigation is repeated. The reaction time of two individuals can then be compared across multiple drops.
For more detail on the set-up of this experiment, watch our high-quality required practical tutorial on YouTube.
Reaction times required practical variables:
Independent variable: The amount of practice an individual has at the ruler drop test
Dependent variable: The drop distance of the ruler (converted into a reaction time)
Control variables: Distance of catching fingers apart, angle of the ruler drop, height of the ruler drop above the catching fingers, ruler size, the amount of warning given to the individual catching the ruler
|
|
|
|
|
|
Sample reaction times required practical results:
|
|
|
|
||
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Source: AQA GCSE Biology (9-1) required practical handbook
AQA GCSE Science subject-specific terminology:
- This experiment is an excellent opportunity to discuss types of errors, as there are many examples in this experiment (e.g. varying between measuring the drop distance from the top or bottom of the catching fingers).
- This can then lead onto a further discussion about what a ‘fair test’ is.
Other blog posts in our AQA GCSE Biology (9-1) Required Practical series:
Getting the most out of GCSE Biology Required Practicals: Microscopy
Getting the most out of GCSE Biology Required Practicals: Microbiology
Getting the most out of GCSE Biology Required Practicals: Osmosis
Getting the most out of GCSE Biology Required Practicals: Food tests
Getting the most out of GCSE Biology Required Practicals: Enzyme activity
Getting the most out of GCSE Biology Required Practicals: Photosynthesis
Getting the most out of GCSE Biology Required Practicals: Plant responses
Getting the most out of GCSE Biology Required Practicals: Field Investigations
Getting the most out of GCSE Biology Required Practicals: Decay