The need for Exchange surfaces, SA:V, full lesson, sheets, models, powerpoint, OCR A ALevel Biology

This resource contains a powerpoint, booklet and model answers designed for students studying Alevel OCR A Biology.

The booklet contains 6 pages with diagrams to label and space to make notes organised into sections which match the powerpoint. The model teacher answers are designed to be used by the teacher in the lesson to write notes on the board.

Powerpoint is 26 slides contains learning objectives, keywords, and clear diagrams and is designed to cover a double lesson.

Lesson covers:

The need for exchange surfaces multicellular vs unicellular
SA:V ratio calculations, formulae to learn, formulae given in exam.
Partial pressures and how this links to conc. gradients and gas exchange.
Lung Surfactant
Adaptations of a efficient exchange surface
Alveoli structure with annotation.