Imagine a world cluttered with dead plants and animals, with nature and cities alike filled with the stench of death. Even worse, imagine no healthy soils to grow food in and no antibiotics to save lives. This would be the world without fungus. The world of fungi extends far beyond mushrooms. Their role as decomposers is vital to the recycling of nutrients on Earth, and life without them would be very different.

What Are Fungi?

In the tree of life, about ____1____ species belong to the broad classification known as the Kingdom of Fungi. Fungus, or plural fungi, are diverse organisms that have some similarities with both plants and animals, but many traits of their own. The most commonly encountered fungi are mushrooms, molds, yeasts and ____2____. Before modern ____3____ (the study of fungi), they were considered to be part of the Plant Kingdom, but we now know they are quite different. There are also many fungus-like organisms that used to be considered a part of the Kingdom, but have since been assigned to other taxa (groups of scientific classification). Along with bacteria, fungi are the most common life forms on Earth. Their ubiquitous distribution is due to their adaptability to any habitat, and the diversity of the many species known to science. Scientists estimate that in reality there are likely over 3 million species of fungi, but most have yet to be formally studied and recognized as unique species. 

The Structure and Form of Fungi

Much like an iceberg in the polar oceans, most of the fungus exists ____4____ the surface. The soil fungi that all ecosystems rely on for the recycling of nutrients is over 90% underground. The common mushrooms we see on the surface are just the fruits, or ____5____ structures of the fungus. In general, they grow from the tips of filaments (hyphae) that make up the bodies, which are called ____6____. They are large underground networks that play important roles in soil health, and in turn help to feed us by supporting agriculture.

Before the invention of the ____7_____ in the 17th century, large mushrooms and molds were all we knew of the world of fungi. We now know that countless other species live microscopic lives in soil and water. Microscopic yeast were essential for ____8____ and beer for much longer, but the nature of these ingredients was not understood until just a few hundred years ago. Millions of human lives have been saved by once unknown microscopic fungi, more on that to follow.

Fungi habitat is species specific, with some preferring to live in water and others living in soil. All require moisture at some point in their life cycle. Most fungi are _____9_____ that help break down dead plant and animal material, creating healthy soils in the process. Some species are ____10_____ that are reliant on host plants or animals to obtain nutrients and reproduce. How do fungi obtain nutrients? They can’t do photosynthesis like plants, and they don’t eat. Instead, fungi secrete special ____11_____ called enzymes onto the surface they are growing on. These enzymes basically do the digesting for them. The result is readily available carbohydrates that are absorbed by the walls of the hyphae, which are long ____12____-like branches of fungus. 

Mushrooms are essential to life as we know it. Without them, ____13____ plants and animals would litter the ground all around us, and a simple infection would be quite deadly. But it’s important to note that most fungi are not edible, and many are _____14_____ if consumed. Never eat a wild mushroom without an expert identification. The next time you explore the forest, think of the infinite fungi living out their lives right beneath your feet. Who knows, maybe the next great medicine will come from these unique organisms.