The hierarchy of biological organisation
The hierarchy of biological organisation

Multicellular organisms are organised in levels. Small structures combine to make larger ones, and each level has a particular function.
Step-by-step lessons covering Edexcel IGCSE Biology Level of organisation for IGCSE Biology. Each lesson works through exam-style questions in Paper 1 and Paper 2 format. Start with the foundational cell biology and core content before moving on to the more data-heavy ecology, genetics and practical-skills topics, which carry a large share of the exam marks.