Lecture on Fungi: Size, Study, Kingdom, and Characteristics

Largest Fungi

• Honey Mushroom: Largest living organism
  • Scientific name: Armillaria ostoyae
  • Covers more than 1500 football fields
  • Estimated to be about 2,400 years old

Study of Fungi

• Mycology: The study of fungi
  • Mycologists: Specialists who can identify poisonous species

Characteristics of Fungi

• Eukaryotic: All fungi are eukaryotic
• Multicellular: Most fungi, with yeast as the unicellular exception
• Non-photosynthetic: Do not carry out photosynthesis

Species and Discovery

• 70,000 species named
• Estimated 1.5 million species exist
  • Many undiscovered species in rainforests

Classification within Kingdom Fungi

• Three main groups:
  • Ancient fungi (left branch)
  • Modern fungi (right branch)
    • Includes mushrooms and yeasts

Differences from Plants

• No chloroplasts: Fungi are heterotrophs
• No true roots, stems, or leaves
• Cell walls made of chitin, not cellulose

Nutritional Methods

• Extracellular digestion: Release enzymes to absorb organic molecules
• Absorptive nutrition: Decompose and absorb nutrients from environment

Types of Fungi

• Saprophytic fungi: Decompose dead and decaying material

  • Important for recycling nutrients like carbon and nitrogen

• Parasitic fungi: Absorb nutrients from living cells

  • Produce specialized hyphae called haustoria
  • Example: Parasitic fungi like A. ramosus

Importance of Fungi

• Decomposition: Critical for nutrient recycling in ecosystems
• Nutrient absorption and recycling: Contribute to plant growth by returning nutrients to food webs