Organic effluents: Waste materials derived from organic matter e.g. animal slurry, silage runoff.

Outbreeding: The breeding of genetically different individuals. This increases diversity (or heterozygosity) & is good; faulty alleles are usually masked by healthy ones

Oxygen Dissociation Curve: Graph displaying how saturation of oxygen in Haemoglobin varies with the partial pressure of oxygen.  Good way of showing the properties of haemoglobin.