Free Week 11 GCSE/iGCSE Biology lesson: aerobic and anaerobic respiration, an exercise/pulse-rate practical, and the phlogiston myth that fooled science for a century.
The final week of Unit 3: two days of mixed, real-life ratio and proportion problems, a self-directed review, extra timed practice, and the Unit 3 assessment. By the end of this week you should feel genuinely confident applying ratio and proportion to real situations, not just isolated exercises.
