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Biology Practical Activities
Examples of biology practical activities
Microscopy
Suitable practical activity
Preparation, staining and examination, using a microscope, of biological samples.
Reason why activity is suitable
Learners are required to:
- appropriately prepare biological sample for staining by applying to the microscope slide
(this could include for example, fixing bacterial samples to the slide, selecting an appropriate thickness of tissue etc.) - follow appropriate staining procedure so as to maintain integrity of sample
- complete preparation of the slide appropriately (e.g. application of cover slip or immersion oil as required)
- demonstrate the ability to use a microscope correctly
(e.g. selecting correct light settings and magnification and focus on the sample correctly at various magnifications) - carry out measurement using micrometer to allow determination / comparison of cell size
- appropriately label cell images with relevant organelles
Unsuitable practical activity
Examination, using a microscope, of pre-prepared slides or pre-stained slides.
Reason why activity is not suitable
This practical only allows the learner to demonstrate a limited array of skills for example their use of the microscope and recording of cell structures and size. This would not present sufficient challenge and does not afford them the opportunity to develop cell preparation and staining techniques which are still relevant in scientific laboratories.
Membrane permeability
Suitable practical activity
Quantitative examination of membrane permeability in beetroot/red cabbage tissue under varying conditions (e.g. temperature, concentration of solution) using spectrophotometry.
Reason why activity is suitable
Learners are required to:
- prepare samples of plant tissue carefully and consistently in order that results can be compared
- accurately set up a range of trials with differing conditions to allow a trend to be observed
- perform repeats at each condition in order to allow averages to be calculated.
- accurately measure pigment released using a spectrophotometer including setup with relevant wavelength selected, calibration with a blank
- accurately recording absorbance values to appropriate number of decimal places
Unsuitable practical activity
Qualitative examination of membrane permeability in beetroot/red cabbage tissue under varying conditions (e.g. temperature, concentration of solution) using colour charts/visual colour comparison.
Reason why activity is not suitable
Use of a colour chart or visual comparison is subjective and not measurable which limits the extent of analysis and interpretation of the data collected.
Enzyme reaction kinetics
Suitable practical activity
Comparing rate of reaction of amylase on starch in the presence of iodine. This could be at different temperatures or using different concentrations of substrate.
Reason why activity is suitable
Learners are required to:
- accurately set up a range of reactions with differing conditions to allow a trend to be observed
- perform repeats at each condition in order to allow averages to be calculated
- accurately measure the time taken for the reaction to reach a specific point such that rates can be compared
- calculate rate of reaction based on the time data collected
Unsuitable practical activity
Comparing rate of catalase enzyme reaction by measuring height of foam produced when reacted with hydrogen peroxide.
Reason why activity is not suitable
Measurement of the height of foam, using a ruler, is not sufficiently accurate for SCQF level 6 Depending on the tube used for the experiment, the heights may not be directly comparable and distance is not an appropriate measure of a gas – this should be a volume. Distance does not necessarily equate to volume and learners at this level would be expected to understand that.
