The chemical reactions and pathways resulting in many of the chemical changes of compounds that are not necessarily required for growth and maintenance of cells, and are often unique to a taxon. In multicellular organisms secondary metabolism is generally carried out in specific cell types, and may be useful for the organism as a whole. In unicellular organisms, secondary metabolism is often used for the production of antibiotics or for the utilization and acquisition of unusual nutrients.

The chemical reactions and pathways resulting in the formation of melanins, pigments largely of animal origin. High molecular weight polymers of indole quinone, they are irregular polymeric structures and are divided into three groups: allomelanins in the plant kingdom and eumelanins and phaeomelanins in the animal kingdom.

The chemical reactions and pathways involving biological pigments e.g. melanin, occurring as part of the development of an organ or organism.

The chemical reactions and pathways resulting in the formation of a pigment, any general or particular coloring matter in living organisms, e.g. melanin.

The chemical reactions and pathways resulting in the formation of naphtho-gamma-pyrone.

The set of specific processes that generate the ability of an organism to induce an abnormal, generally detrimental state in another organism.

The aggregation, arrangement and bonding together of a set of components to form an asexual spore wall, the specialized envelope lying outside the cell membrane of a spore derived from an asexual process. Examples of this process are found in Bacterial and Fungal species.

Any process that results in a change in state or activity of the symbiont or its cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of detecting molecules of its host organism. The host is defined as the larger of the organisms involved in a symbiotic interaction.