What characterizes mould as a microorganism?

Mould is a type of fungus that is commonly characterized by its fuzzy appearance on various surfaces, including food. This distinctive look results from the growth of fungal filaments, known as hyphae, which cluster together and can be seen as a soft, fuzzy texture. Mould thrives in environments with suitable moisture and nutrients, often leading to its growth on food items, which may be indicative of spoilage.

While mould can be harmful, not all moulds are detrimental to health, as some are used in food production (such as in cheeses). Moreover, moulds can grow on both living and dead organic materials, contrary to the idea that they cannot thrive on dead matter. Thus, the characteristic fuzzy appearance is a key identifier of mould as a microorganism.