Ultrafiltration (CIE A-level Biology)

This lesson explains how the structure of the Bowman’s capsule leads to the formation of glomerular filtrate by ultrafiltration. The PowerPoint and accompanying resource are part of the 1st lesson in a series of two lessons which have been planned to cover the content of points (6 and 7) of topic 14.1 of the CIE A-level Biology specification (for assessment in 2025-27)

The lesson provides students with the opportunity to gauge a deep understanding of ultrafiltration and be able to explain how the mechanisms found in the glomerulus and the Bowman’s capsule control the movement of small molecules out of the blood plasma. Key terminology is used throughout and students will learn how the combination of the capillary endothelium and the podocytes creates filtration slits that allow glucose, water, urea and ions through into the Bowman’s capsule but ensure that blood cells and plasma proteins remain in the bloodstream. A number of quiz competitions are used to introduce key terms and values in a fun and memorable way whilst understanding and prior knowledge checks allow the students to assess their understanding of the current topic and to challenge themselves to make links to earlier topics. The final task of the lesson challenges the students to apply their knowledge by recognising substances found in a urine sample that shouldn’t be present and to explain why this would cause a problem

The 2nd lesson in this series covers selective reabsorption.