BM108

• the two types of eukaryotic organism are protists and metazoans
• protists are single celled eukaryotes that carry out life functions
• metazoans are multi celled eukaryotes that have specialised cells for specific functions
• bilateral symmetry is associated with cephalisation (the differentiation of a head)
• internal germ layer: endoderm
• middle germ layer: mesoderm
• external germ layer: ectoderm
• coelomates have a body cavity entirely within the mesoderm