Practical Scheme of Work

Introduction to the new PSOW

Practical skills will be essential for the assessed individual investigation. This investigation is the "Internal Assessment" and one single piece of work will have a weighting of 20% of the final marks. There are no other assessed pieces of practical work.

The great strength of being able to design your own programme, most of which does not have to be assessed, is that practical work can be fully integrated into good biology teaching. The new PSOW allows the teacher to choose the most suitable experiments for their students. There are no specified protocols to use and teachers are encouraged to allow students to design their own investigations through an inquiry-based approach. Students will not become Rosalind Franklyn or Louis Pasteur over-night. The PSOW will need to introduce practical skills step by step. There are a wide range of practical skills identified in the guide under "skills" and there are lots of examples on this website.

It would be wise to cover as many of these experiments as possible too. Together this makes quite a full practical scheme of work

Seven prescribed experiments

There are seven experiments which are prescribed by the new biology guide. An understanding of these experiments will be assessed in the first section of paper 3. Students will need to have hands on experience of these experiments in particular. The guide does not specify exactly how these should be carried out and there is plenty of opportunity to tailor these experiments to the needs of the students, the type of learning which is taking place or the resources available in the lab.

Fifty-five practical skills or applications mentioned in the new guide

The section entitled "Applications and skills" makes reference to a large number of biological practical skills. There is no obligation to include any specific experiment but any of the skills may be assessed in the new section A of paper three so students will need to have some experience. It is left for the teacher to choose exactly how to do this and demonstrations, data analysis exercises or simulations could be used where individual practical work is not suitable.

An Independent Investigation which forms the "Internal Assessment"

This will be a single investigation taking about 10 hours. The task should be detailed and include a research question supported by a scientific rationale. The student will have to show that they have used their initiative and have personalised any standard protocols used. The final report should be between 6 and 12 pages long. Not more than 12 pages. Like other practical work the investigation can be a hands-on lab or it could be a simulation, a modelling exercise, but must be in some way open-ended. It will be assessed on five criteria; personal engagement, exploration, analysis, evaluation, and communication.

The Group 4 Project

Apart from the Group 4 Project everything else a student does towards their assessment must be individual. This goes against how science works in reality where teams of scientists from different disciplines often work together to solve a common problem. This is what the Group 4 Project tries to imitate. It is a collaborative activity whereby students studying different science subjects come together to work on a scientific or technological problem. It should also address Aims 7 and 8 which are concerned with global citizenship, ethical issues and 21st century communication skills. The new 2014 guide stipulates that a reflective statement written by each student on their involvement in the Group 4 Project must be included on the cover sheet of their internally assessed Investigation. There is no other assessment of the project.

Other Practical work or field work

There are many other opportunities for practical work during an IB biology course and they can all contribute to the PSOW.

Details of the seven prescribed experiments

P1 1.1 Calculation of magnification of drawings, actual size of structures from drawings or micrographs

P2 1.4 Estimation of osmolarity in tissues

P3 2.5 Investigation of a factor affecting enzyme activity

P4 2.9 Separation of photosynthetic pigments by chromatography

P5 4 Attempting to create a sealed mesocosm

P6 6.4 Monitoring of ventilation at rest and after mild and vigorous exercise

P7 9.1 Measurement of transpiration rates using potometers

Details of the practical skills mentioned in the new guide.

Topic Labs referred to in the "Skills" section of the SL topics of the new guide
1,1 Microscopy of tissues (magnification)
1,1 Electron micrographs, identify organelles/function
1,6 Mitosis stages/Mitotic index/root squash
2,3 Molecular visualisation software of cellulose, starch & glycogen
2,3 Calculate BMI
2,4 Denaturation of proteins
2,5 Effect of pH/temp/conc on enzyme activity (Design)
2,5 Immobilised lactase
2,6 Isolation of DNA
2,8 Respirometer/germinating seeds/invertebrates
2,9 Limiting factors of photosynthesis
3,1 Genbank database for base sequence differences
3,2 Karyogram activity/Trisomy
3,2 Use of databases to identify the locus of a human gene and its polypeptide product
3,3 Observation of meiosis
3,4 Predicted/actual outcomes of genetic crosses
3,5 Design of an experiment to assess one factor affecting the rooting of stem cuttings.
4 Quadrats and use of Chi-squared test
4 Analysis of air monitoring data
5,3 Classification of one species
5,3 Plant and animal group recognition features
5,3 Construction of a dichotomous key
6,1 Dialysis tubing gut model
6,1 Identification of tissue layers in transverse sections of small intestine microscope slides or micrographs
6,2 Blood vessel histology
6,2 Heart dissection
6,5 Analysis of oscilloscope traces for resting and action potentials
Topic Labs referred to in the "Skills" section of the AHL of the new guide
7,1 Using molecular visualisation software to analyse the association of DNA/Histone in nucleosomes
7,3 Using molecular visualisation software to analyse the structure of tRNA & eukaryotic ribosomes
8 Use of databases to identify anti-malarial drugs
9,1 Xerophyte/Halophyte adaptation
9,1 Transpiration stream modelling
9,1 Xylem/Phloem/Stem/Root histology
9,1 Design an experiment to test hypotheses about the effect of temperature or humidity on transpiration rates
9,3 Micropropagation of plant tissues on nutrient gels with plant hormones
9,4 Seed structure
9,4 Flower structure
9,4 Factors affecting germination
10,2 Chi squared test on data from dihybrid crosses
11,1 Measurement of sarcomere from microscope slides or micrographs
11,4 Gonad histology
Topic Labs referred to in the "Skills" section of the option of the new guide
Opt A 3 Eye dissection
Opt A 4 Invertebrate behaviour labs
Opt B 1 Grams staining
Opt B 1 Zone of inhibition due to bactericides
Opt B 1 Fermenter
Opt B 5 Use of software to align two protein sequences
Opt C 1 Transect
Opt C 2 Investigate the effect of an environmental disturbance on an ecosystem
Opt C 4 Simpson's Index
Opt C 5 Capture-mark-release
Opt C 6 Nutrient content of soil sample
Opt D 1 Determination of food energy content by combustion
Opt D 1 Dietary analysis using databases
Opt D 4 Heart Rate lab
Opt D 4 Analysis of epidemiological data on CHD
Opt D 6 Identification of pneumocytes, capillary endothelium and blood cells in light micrographs
Topic Labs referred to in the "Application" section of the option of the new guide
1,4 Gelatin cube cell model
2,2 Calorimetry to investigate thermal properties of water / methane
2,8 Yeast/Yoghurt fermentation
2.3, 2.4 Nutrient tests
4 Counting frames
5,2 Simulation of natural selection
6,4 Peak flow meter
6,4 Recovery rate
6 Heat loss modelling
6 Reaction timer
9 Shallot onion root growth

Details of the seven prescribed experiments and the practical skills - as a pdf sheet and in  Word format  

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