Chapter 2: Biological Classification
NCERT Biology | NEET-UG Preparation | Chapter Summary
Learning objective: Understand the development of biological classification, the five-kingdom system, the major characteristics of different kingdoms, and the differences between viruses, viroids, prions and lichens.
Kingdom Fungi
Fungi are eukaryotic, heterotrophic organisms that obtain nutrients by absorption. Most fungi are multicellular, while yeast is unicellular.
General characteristics
- The cell wall commonly contains chitin and other substances.
- The body of a typical fungus consists of thread-like hyphae.
- A network of hyphae is called a mycelium.
- Fungi may be saprophytic, parasitic or symbiotic.
- Reproduction can be vegetative, asexual or sexual.
Major groups of fungi
- Phycomycetes: Traditionally include forms such as Rhizopus and Mucor. Their hyphae are generally aseptate and coenocytic.
- Ascomycetes: Called sac fungi. Sexual spores, called ascospores, are formed inside asci. Examples include yeast, Aspergillus and Penicillium.
- Basidiomycetes: Sexual spores called basidiospores are produced on basidia. Examples include mushrooms, puffballs and rust fungi.
- Deuteromycetes: Traditionally called imperfect fungi because only their asexual or vegetative stages were known in the classification described in older textbooks.
Importance of fungi
- They decompose dead organic matter and recycle nutrients.
- Some are used in food production and fermentation.
- Some produce useful substances, including antibiotics.
- Some cause diseases in plants and animals.
NEET focus: Ascospores are associated with asci; basidiospores are associated with basidia. Learn the examples of each group from NCERT.
