International A Level Biology / Practical Skills in Biology I

Percentage change, ratios and rates

Edexcel International A Level Biology (YBI11), chapter 13: Practical Skills in Biology I, specification point A.0.3, A.0.1. Part of the full course.

Read the revision notes · International A Level Biology past papers

Percentage changes, ratios and rates help you compare practical results and describe how measurements change. Using the correct reference value, order and units earns clear calculation marks.

More lessons in Practical Skills in Biology I

• Variables, controls and a fair test
• Planning an experiment for Unit 3
• Accuracy, precision, validity and repeatability
• Significant figures, units and results tables
• Evaluating results and suggesting improvements
• Drawing and reading graphs
• Mean, range, standard deviation and error bars