Indoor Air sciences CSMI Practice Exam

The mycelium is primarily made up of:

1. Cellulose

2. Protein

3. Hyphae

4. Spores

The correct answer is: Hyphae

Mycelium is the vegetative part of a fungus and is primarily composed of a network of thread-like structures known as hyphae. These hyphae are responsible for nutrient absorption and play a critical role in the growth and reproduction of fungi. Hyphae can vary in structure, but they all share the fundamental function of facilitating the growth of the mycelium through nutrient uptake from the surrounding environment. While the other options represent various components or products associated with fungi, they do not accurately reflect the primary composition of mycelium. For instance, cellulose is a structural component found in plant cell walls, not in the fungal structure of mycelium. Protein, while present in mycelium, is not the main component; rather, it is synthesized as part of the metabolic processes that occur within the hyphae. Spores are the reproductive units of fungi, scattered by the mycelium to establish new fungal growth, but they are not part of the mycelial structure itself. Thus, hyphae are the defining and primary element making up the mycelium of a fungus.