Year 12 is divided into four modules. Module 1: Development of practical skills in Biology (Year 12 and 13) Practical skills are embedded throughout all the content of this specification. Learners will be required to develop a range of practical skills throughout their course in preparation for the written examinations. Module 2: Foundations in Biology This module gives learners the opportunity to use microscopy to study the cell structure of a variety of organisms. Module 3: Exchange and Transport In this module, learners study the structure and function of gas exchange and transport systems in a range of animals and in terrestrial plants. Module 4: Biodiversity, Evolution and Disease In this module the learners study the biodiversity of organisms. It serves as an introduction to ecology, emphasising practical techniques and an appreciation of the need to maintain biodiversity. Two further modules will be completed in Year 13. Module 5: Communication, Homeostasis and Energy It is important that organisms, both plants and animals are able to respond to stimuli. This is achieved by communication within the body, which may be chemical and/or electrical. Module 6: Genetics, Evolution and Ecosystems This module covers the role of genes in regulating and controlling cell function and development. Heredity and the mechanisms of evolution and speciation are also covered.