(1) A form of nourishing substance that is consumed
Food is the essential source of nutrient (such as carbohydrates, proteins, fats, vitamins, or minerals) ingested or assimilated by the organism to sustain life. Food may be derived from another living thing through predation, parasitism, etc. For embryos, yolk is their food that serves as their fundamental source of nourishment. For most photosynthetic plants, their food is the product of their own photosynthesis whereas many animals depend on the plants as their direct food. For microorganisms such as bacteria and protozoa, their food is chemical compounds from their environment.