Final answer:
Fungi encompass molds, mildew, and mushrooms, with mushrooms being up to 90 percent water. Molds are important decomposers and used in pharmaceuticals, but also cause allergies and mycotoxins. Water molds, belonging to Oomycota, differ from true fungi and include significant plant pathogens such as the one responsible for the Irish potato famine.
Step-by-step explanation:
Fungi, including molds, mildew, and mushrooms, are a diverse group of organisms. Mushrooms are widely known to consist of up to 90 percent water. Molds, one of the types of fungi, play a significant role in ecosystems by decomposing dead organic matter. They consist of long filaments that form visible colonies and can thrive in a variety of environments such as soil, rotting food, and moist corners of homes. Some molds are beneficial for producing pharmaceuticals like penicillin and cyclosporine, but they can also cause allergies and produce harmful mycotoxins.
Water molds, distinct from true fungi, were once grouped with fungi due to their morphological similarities. However, they belong to the group Oomycota and have a cellulose-based cell wall, a characteristic separating them from true fungi. They include plant pathogens responsible for diseases like the late blight of potatoes, which led to the Irish potato famine in the 19th century. Their lifecycle involves diploid spores with two types of flagella for movement. Water molds play various ecological roles and can be saprobes or parasites in aquatic and terrestrial environments.
The early fungi likely originated in water, and they might have been similar to present-day molds. Fungi are critical to life on Earth due to their decomposition abilities and some engage in beneficial symbiotic relationships with plants, such as those in the Glomeromycota group. Being eukaryotic organisms, fungi, including bread molds and Oomycota such as Phytophthora, are vital for a balanced ecosystem, but can also pose challenges for agriculture and biodiversity when acting as pathogens.