Plant defense against herbivory which differ from one another in both functional groups, and in basic carbon skeletons. Monoterpenoids, continuing 2 isoprene units, are volatile essential oils such as citronella, limonene, menthol, camphor, and pinene. Diterpenoids, 4 isoprene units, are widely distributed in latex and resins, and can be quite toxic. Diterpenes are responsible for making "Rhododendron" leaves poisonous. Plant steroids and sterols are also produced from terpenoid precursors, including vitamin D, glycosides (such as digitalis) and saponins (which lyse red blood cells of herbivores). Phenolics, sometimes called "phenols", consist of an aromatic 6-carbon ring bonded to a hydroxy group. Some phenols have antiseptic
Nothing comes from nothing the song "Something Good", which contains the lyrics: "Nothing comes from nothing / nothing ever could". Although the song is devoid of intentional metaphysical connotations, Maria's time in Nonnberg Abbey would have familiarized her with the phrase, which is used in Catholic philosophy to explain God's gratuitous act of , namely, that only the source of all being can give creation its existence. Earlier in the film, in the well-known song "Maria", Maria's fellow nuns lament that there is "many a thing she ought to understand" and that she is "not an asset to the abbey". It is unclear if