| Introduction |
The fungi constitute a unique kingdom of heterotrophic organisms showing great diversity in morphology and habitat. |
| Common Examples |
Fungi on moist bread and rotten fruits, mushrooms, toadstools, parasitic fungus on mustard leaves, yeast used in bread and beer, wheat rust-causing Puccinia, antibiotic source Penicillium. |
| Habitat |
Cosmopolitan; found in air, water, soil, on animals, and plants; prefer warm and humid places. |
| Body Structure |
Filamentous with bodies consisting of long, slender thread-like structures called hyphae; network of hyphae is known as mycelium; cell walls composed of chitin and polysaccharides. |
| Types of Hyphae |
Coenocytic hyphae (continuous tubes with multinucleated cytoplasm) and septate hyphae (with cross walls). |
| Nutrition |
Mostly heterotrophic; saprophytes (absorb organic matter from dead substrates), parasites (depend on living plants and animals), and symbionts (association with algae as lichens and with roots of higher plants as mycorrhiza). |
| Reproduction Methods |
Vegetative: Fragmentation, fission, budding. Asexual: Conidia, sporangiospores, zoospores. Sexual: Oospores, ascospores, basidiospores. |
| Sexual Cycle Steps |
1. Plasmogamy: Fusion of protoplasms between two gametes. 2. Karyogamy: Fusion of two nuclei. 3. Meiosis: Occurs in zygote resulting in haploid spores. |
| Dikaryon Stage |
In ascomycetes and basidiomycetes, an intervening dikaryotic stage (n + n) occurs before parental nuclei fuse and cells become diploid. |
| Basis for Classification |
Morphology of the mycelium, mode of spore formation, and type of fruiting bodies. |
