While not every microorganism is dangerous, some microorganisms can cause disease and infections in humans and other living things. Microorganisms, also called microbes, also contribute to decomposition and spoilage of food, and they can leave toxic waste products behind even if they are eradicated from the contaminated material.
In some cases, microorganisms can have beneficial effects in small populations, but an overgrowth can cause issues. For instance, the bacteria that lives inside the human digestive tract, when balanced by other microbes in the body, serves an important purpose in the digestive process. However, an imbalance of nutrients or a weakened immune system can allow bacteria populations to grow, leading to an intestinal infection and potentially to a dangerous illness.Learn More
Fungi damage wood, crops and other resources, and can cause serious illnesses in humans. When food or other products are contaminated by fungi, the products are typically destroyed.Full Answer >
The chief difference between prions and viruses is that, while both cause disease, prions have no genetic material of their own. According to Merck, prions also differ from viruses in that prion-caused conditions are always fatal. Most viral illnesses can be survived. Prions tend to strike at the nervous system more often than at any other part of the body.Full Answer >
Bacteria are typically single-celled organisms called prokaryotes that may serve as digestive aids, cause disease or aid in decomposition. Unlike eukaryotes, they do not have nuclei. Bacteria contain their DNA and other genetic material as a single strand in their cytoplasm, and they reproduce through a process called binary fission.Full Answer >
A few species of moths ingest plants that contain cardenolides, a group of poisons that affect the heart muscle and are dangerous to humans when eaten. Otherwise moths are harmless. Moths do not bite or sting, and they have many beneficial effects on the ecosystem.Full Answer >