All moral rights asserted. Recolouring or alteration of the image is prohibited without permission. Coloured scanning electron micrograph (SEM) of a fruiting body of a Dictyostelium discoideum social amoeba, or slime mould. Under favourable conditions, D. discoideum lives as a unicellular organism in the soil. When there is a lack of nutrients, the unicellular amoeba form a multicellular aggregation known as a slug. The cells within the slug differentiate, with some forming a fruiting body, or sorocarp, on a long stalk, which releases spores when mature. D. discoideum is being researched for use as a unicellular 'factory' to produce a number of molecules including antibiotics and olivetolic acid, a precursor of tetrahydrocannabinol (THC), the psychoactive substance in cannabis. Magnification: x150 when printed at 15 centimetres wide.