Diffusion, Osmosis and Active Transport
These resources can be used in the delivery of lessons on transport (diffusion, osmosis and active transport) at KS4. It is intended that the sequence of lessons would be as follows:
1. Diffusion (using either the "Diffusion experiment" or the practical guide to illustrate the process). The animation can also be shown a an explanation or a summary at the end of the lesson.
2. Osmosis (using the "Osmosis Activity"). The "Egg osmosis" experiment can also be set up at this point and left to run over the course of the next week. The animation can again be used to introduce or to summarise the process.
3. Active transport (if appropriate to the specification) (using the BBC Bitesize animation and some or all of the worksheet).
Diffusion animation
This is a basic animation showing the process of diffusion with an explanation. It could be used on a whiteboard to explain the topic, or for students to either find out about the topic for themselves or as a revision tool.
Diffusion experiment
A worksheet with an experiment on diffusion. Once the idea of diffusion has been introduced, students can work through the activities and questions on the sheets. The practical should be completed within a lesson, but the questions may take longer; they could be completed for homework.
Teacher notes are also available: http://serendip.brynmawr.edu/sci_edu/waldron/pdf/MembraneTeachPrep.pdf
Practical Guide 1: Gas Exchange and Transport in Plants and Animals
Pages 9-13 contain ideas for practical work to illustrate the site of gas exchange in plants. This resource is best used by selecting one or two of these experiments to run in class as an example of diffusion in action.
Osmosis animation
This is a basic animation showing the process of osmosis with an explanation. It could be used on a whiteboard to explain the topic, or for students to either find out about the topic for themselves or as a revision tool.
Osmosis activity
A worksheet with an experiment on osmosis. Once the idea of osmosis has been introduced, pupils can work through the activities, completing the practical and the accompanying questions. Teacher notes are also available: http://serendip.brynmawr.edu/sci_edu/waldron/pdf/OsmosisTeachPrep.pdf
Egg osmosis
This worksheet talks through a practical involving placing a raw egg into a variety of solutions and observing the effects on the egg. The aim is to investigate the effects of osmosis on a single cell. The investigation lasts for 7 days, although the amount of time spent in class looking at the results would be minimal. Recommended as a whole class activity, rather than for individual students.
BBC Bitesize Active Transport animation
This page of the BBC Bitesize site has brief notes and an animation showing the process of active transport. It could be used as either an introduction or a revision exercise for a KS4 class (NB Active transport does not feature in many of the specifications for GCSE; OCR 21st Centruty Science is one that does).
Nuffield Co-ordinated Sciences: Biology Worksheets
Pages 84 and 85 (Activity B9b) have information on and data from an experiment about active transport in plants. The analysis questions at the end of the worksheet would be most suitable for higher sets, or as an extension activity for gifted and talented students in a class. The first few questions, however, should be accessible to most KS4 students. The activity would be best used as a consolidation or HSW exercise after teaching the theory of this topic.