What is the nature of matter and the chemical bond. The chemistry of living systems at a macro and micro level. Analysis to give empirical formulae and the existence of isomeric forms of compounds. Molecules as distinct entities with particular properties and not simply blends of the properties of its constituents. Optimal reaction rates in chemical (reductionist) and biological (complex) systems. The failure of Perkin to synthesise quinine. The development of colours from natural sources and by synthesis. The use of gene transfer and fermentation to make colours. Plant breeding and the relationship between genotypic and phenotypic variation in peas. The corpuscular nature of genetics and the absence of inherited. Average properties. Genetic modification and gene editing using CRISPR. The manipulation of genes to produce different polyketides. Soil microorganisms and diseases of plants and the link back to crop rotation. The use of natural and synthetic fertilisers.