Apparatus and techniques

You need to have knowledge of the following pieces of apparatus and become familiar with the techniques listed.

Note: the apparatus and techniques noted below can be assessed in the question papers.

Apparatus

• beaker
• balance
• measuring cylinder
• dropper/pipette
• test tube/boiling tube
• thermometer
• funnel
• syringe
• timer/stopwatch
• Petri dish
• water bath
• colorimeter
• pulsometer
• sphygmomanometer

Techniques

• using gel electrophoresis to separate macromolecules, for example DNA fragments
• using substrate concentration or inhibitor concentration to alter reaction rates
• measuring metabolic rate using oxygen, carbon dioxide and temperature probes
• using a respirometer
• measuring pulse rate and blood pressure
• measuring body mass index

Candidates should be familiar the terms ‘control’, ‘validity’, ‘reliability’, ‘independent variable’, and ‘dependent variable’ and be able to comment on these in experimental set-up questions.

Control: a control experiment is set up exactly the same but without the treatment being applied to show the effect is due to the treatment.

Validity: all variables except the independent variable are controlled so it can be concluded that the effect is due to the independent variable.

Reliability: measurements are repeated at each level of the independent variable to reduce the effect of atypical results.

Independent variable: the variable that is changed in a scientific experiment.

Dependent variable: the variable that is measured to give results in a scientific experiment.