Mycology Basics Quiz

Mycology

Mycology is the branch of biology that studies fungi, including their growth, structure, genetics, ecology, classification, and use. Fungi, which includes yeasts, molds, mushrooms, rusts, smuts, mildews, puffballs, bracket fungi, truffle-like fungi, jelly fungi, and lichens, have been used throughout history by humans for many purposes such as food sources, medicines, and agriculture. There are approximately 90,000 different species described today; however, some experts estimate there may actually be several million more undescribed species.

Taxonomy of Fungi

Fungi belong to the kingdom Fungi, partaken with mosses and liverworts, algae, slime moulds, and higher plants. They form one of five major domains recognized by molecular geneticists. As mycologists study fungi's classification, they divide them into various classes based on characteristics like cell walls, reproduction methods, spore shape, and other physical features.

There are four groups of fungi: Chytridiomycota, Zygomycota, Ascomycota, and Basidiomycota. Each group has its own unique characteristics related to sexual processes, hyphae formation, asexual spores production, etc. For example, chytrids are aquatic microscopic organisms while zygomycetes produce large fruiting bodies called stromata containing numerous zoospores and aerothodes.

Environmental Impact of Fungi

Environmental mycologists focus on how fungi interact with other living things around them, considering their role in decomposition, recycling nutrients back into soil ecosystems, etc. Some common decomposers include saprophytes—fungi that feed off dead organic matter like decayed wood, leaves, fruits, grass clippings, etc—and parasites—organisms that live off another organism without killing it first.

Some fungal species can help clean up pollutants from water, air, and soil environments. For instance, certain white rot fungi break down toxic chemicals found near old gas stations. Additionally, ericoid mycorrhizae help trees absorb nutrient minerals better under acid conditions, making forest soils healthier for plant growth, especially critical in areas where logging harms topsoil.

Genetic Properties of Fungi

Like all biological entities, fungi possess genes responsible for determining their size, color, reproductive patterns, life cycles, etc., generally inherited through chromosomes passed along during meiosis. Fungal DNA exists within nuclei (in cells) plus mitochondria present outside of most nucleated cells. Recent scientific discoveries suggest chromosome fragments called centromeres have tiny repeat sequences coding for proteins needed to separate sister chromatids during cell division.

Several researchers argue that all eukaryotic species share similar types of repeats due to common ancestry. However, distinct repetitive elements distinguish each family of fungi. Some scientists believe these "rare repeat families" might serve useful functions when speculating how new genes arise over time via gene copying mechanisms.

Biochemical Properties of Fungi

The chemical makeup of fungi plays a significant role in understanding why they behave differently compared to other organisms. Fungi synthesize enzymes which enable them to degrade complex polysaccharides, lipids, aromatic compounds, etc. This process helps fuel decomposition activities necessary for maintaining healthy ecosystems, breaking down wastes, and returning essential nutrients back into circulation.

Many mycolytic enzymes are secreted extracellularly and involve hydrolysis reactions. These enzymes enable fungal colonization of diverse substrates because fungi cannot digest cellulose themselves but do secrete lignolytic enzymes capable of degrading cellulosic materials. By breaking down biopolymers into smaller molecules that other organisms can utilize further, fungi play vital roles in global nutrient cycling.