Explain the Kingdom Fungi organisms?
Kingdom Fungi consists of mostly eukaryotic, multicellular, non-photosynthetic organisms that derive their nutrients by absorption. Fungi are grouped separately from the other Kingdoms mainly because of their unique mode of nutrition. Not too long ago the fungi were grouped within Kingdom Plantae, since the cells of fungi are filamentous and have cell walls. Scientists now believe that the differences between fungi and plants are significant enough to merit placing them in their own kingdom. Fungi lack chlorophyl, and instead, secrete enzymes to dissolve food into smaller molecules, which can then be absorbed. This is known as a saprophytic life style. As such, fungi make up a large part of the decomposers in a food web.
The cell walls of fungi are not made of the same material contained within plant cell walls. Plant cell walls are composed of cellulose, while fungal cell walls are made of chitin, the material that makes up the shells of Arthropods. The vegetative body structure of a fungus consists usually of filaments called hyphae that grow through wood, penetrate the ground, or grow within the tissues of a host. These filamentous hyphae are sometimes walled off into cells by cross walls called septa. A mass of hyphae is referred to as a mycelium.
Many fungi reproduce sexually as well as asexually. Sexual reproduction in fungi occurs when two nuclei from two distinct mating strains fuse. In some fungi, the nuclei do not fuse right away but form pairs, making the hyphae dikaryotic, having two genetically different nuclei. Eventually the two nuclei will fuse and form (1N) spores through meiotic division. Asexual reproduction among fungi takes place through the production of spores formed from sporangia, or conidiospores formed from conidia.
The Fungi are divided into 3 Divisions:
Zygomycota - form characteristic zygospores, and include the bread molds
Ascomycota - form characteristic sac-like reproductive structures called asci, and include truffles, yeasts, morels, and molds
Basidiomycota - form characteristic basidia, which are club-shaped reproductive structures, and include mushrooms, toadstools, puffballs, bracket fungi, rusts, and smuts
We will examine Zygomycota (molds) and lichens, special organisms made of both a fungus and a plant, in greater detail.