1. chemical compounds necessary for normal plant growth. 2. chemical compounds that cannot be made by a specific organism but are important for the organism to survive.
1. chemiese verbindings noodsaaklik vir normale plantgroei. 2. chemiese verbindings wat nie deur 'n spesifieke organisme gemaak kan word nie, maar wel belangrik is vir oorlewing van die organisme.
