2.1.1 Use of apparatus and techniques

When would you use colorimetry?

Method to measure substance concentration in a solution by analyzing light absorbance/transmission of a specific wavelength. Used in chemistry and biochemistry to analyze sample substance concentration.

When would you use a potometer?

Device used to measure the rate of transpiration in plants. It is used to investigate the effect of environmental factors on the rate of water uptake by a plant.

When would you carry out serial dilution?

A method to create lower concentrations of a concentrated solution, often used in microbiology to measure bacteria concentration.

When would you use electrophoresis?

A laboratory technique that separates DNA, RNA or proteins based on their size and charge. It is used for DNA fingerprinting, disease diagnosis, and drug development.

When would you use thin layer/paper chromatography?

Separation technique used to identify and quantify small organic molecules in a mixture.

How do you ensure the safe use of instruments for the dissection of animals or an organ?

* Wear personal protective equipment (PPE)


* Keep sharp instruments pointed away from yourself and others
* Dispose of used instruments in a sharps container
* Clean instruments with appropriate disinfectant after use.

When do you use which sampling techniques in field work?

Systematic sampling is used when a pattern is present in the population. Cluster sampling is used when the population is geographically dispersed. Stratified sampling is used when the population can be divided into subgroups based on a characteristic of interest. Random sampling is used when the population is homogenous and there is no pattern present.

How do you ensure the safe and ethical use of organisms in school practicals?

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