Practical Skills In Biology: The 12 Practicals

So I’m not going to go into too much detail as to why I think the new practical arrangements could actually be a good thing for Sciences at A Level as @hrogerson (http://geordiescience.blogspot.co.uk/2014/04/why-getting-rid-of-practical-assessment.html) and @alomshaha (http://sciencedemo.org/2014/04/uk-science-going-killed-changes-practical-work-schools/) have already got there. I am going to have a think about what the 12 Core Practicals might look like.

12 Practicals in two years could actually be much more than any A Level class does now, as for OCR you could only do 2 (a Qualitative and Quantitative) and for AQA you could only do 1 (The EMPA or ISA). It would be hard not to prepare students for this by doing some sort of practice practical but it’s possible to prepare students through a paper exercise. If you do the ISA route for AQA then there are 6 marks for students doing practicals in lessons but that is just a sheet that the teacher signs which isn’t checked at all so open to abuse. Edexcel has a version of the Core Practical concept that the DfE have announced; particular practicals are learning objectives and there are questions on them in the exams. There is only a tick sheet to confirm that the students have done these practicals, which is just as open to abuse as the AQA one however in the A2 year students have a project to complete, an independent piece of practical work. The AS Core Practicals are designed to build up the students’ practical skills so they can do the project. If a teacher did not do these practicals with their students then they would find the final project incredibly hard as it does require a lot of time. I usually had a month of teaching dedicated to the project when I taught Edexcel.

The minimum of 12 practicals have to address particular techniques outlined in the DfE document, so here are some ideas about what practicals the students might have to do.

  1. use appropriate apparatus to record a range of quantitative measurements (to include mass, time, volume, temperature, length and pH): This could be any quantitative practical including enzyme reactions, diffusion, osmosis, photosynthesis, respiration and field work.
  2. use appropriate instrumentation to record quantitative measurements, such as a colorimeter (membrane permeability with temperature or ethanol e.g. beetroot or quantitative Benedict’s)  or potometer (measuring transpiration)
  3. use laboratory glassware apparatus for a variety of experimental techniques to include serial dilutions (enzyme or substrate concentration, osmosis, diffusion)
  4. use of light microscope at high power and low power, including use of a graticule (root tip squash for mitosis, measuring size of cells e.g. cheek, blood, onion epiermis)
  5. produce scientific drawing from observation with annotations (microscopy and dissection)
  6. use qualitative reagents to identify biological molecules (Benedict’s, Biuret, Iodine, Emulsion tests)
  7. separate biological compounds using thin layer/paper chromatography (amino acids or chlorophyll) or electrophoresis (DNA fragments or protein analysis)
  8. safely and ethically use organisms to measure:
    1. plant or animal responses (tropism in plants, turning behaviour in woodlice, eye stalk retraction in snails)
    2. physiological functions (measuring heart rate of daphina with caffeine, measuring breathing in humans)
  9. use microbiological aseptic techniques, including the use of agar plates and broth (antibiotic properties of plant compounds, use of antibiotic multidiscs, Gram staining)
  10. safely use instruments for dissection of an animal organ, or plant organ (heart, eye, kidney, flower)
  11. use sampling techniques in fieldwork (random sampling and systematic sampling for plants and animals
  12. use ICT such as computer modelling, or data logger to collect data, or use software to process data (data loggers can be used for many plant and respiration experiments)

This therefore has the potential to have excellent opportunities practical work throughout the AS and A2 year. What’s interesting in the Ofqual document is this: “There will not be any non-exam assessment of practical skills for AS qualifications. However, the requirement for practical work to be undertaken and for the conceptual knowledge and understanding of practical skills to be assessed in the exams remains.” (page 12)

This could mean that an A2 Project that is internally assessed is still possible.

Of course one of the things that worries teachers is that these Core Practicals will not be done as in class practicals and any tick sheet will just be filled out with no checks from the exam board. Today I read on the Biotutor Chat forum a comment from someone in Edexcel that even though the details are still to be finalised it looks like that evidence will be required that the core practicals are carried out e.g.  a tick list and written evidence of student work (lab book) to a standard of competency. This evidence can all then be moderated; so it’s likely there will be visiting moderators going to centres to check that practical work is being carried out.

So personally I think these changes could be very good for A Level Practical Work in Biology.

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