Kingdom Fungi – Structure, Nutrition and Reproduction
Kingdom Fungi organisms are heterotrophic (Saprophytes). Fungi are cosmopolitan and occur in air, water, soil and on animals and plants.
· Fungi are filamentous (except yeast which is unicellular)
· Their bodies consist of long, slender thread-like structures called hyphae. The network of hyphae is known as Mycelium.
· Some hyphae are continuous tubes filled with multinucleated cytoplasm – these are called coenocytic hyphae. Others have septae or cross walls in their hyphae.
· The cell walls of fungi are composed of chitin and polysaccharides.
· Most fungi are heterotrophic and absorb soluble organic matter from dead substrates and hence are referred to as saprophytes.
· Those that depend on living plants and animals are called parasites.
· They can also live as symbionts – in association with algae as Lichens and with roots of higher plants as Mycorrhiza.
a) Vegetative – fragmentation, fission and budding.
b) Asexual reproduction – by spores called conidia or sporangiospores or zoospores.
c) Sexual reproduction – by oospores, ascospores and basidiospores.
The various spores are produced in distinct structures called fruiting bodies.