Fungus and Fungal Diversity

Fungi

kingdom of eukaryotic organisms that absorb nutrients from their surroundings

Ascomycota and Basidiomycota

Two Major Divisions of Fungi

Ascomyocota

• ("sac fungi")

  • Includes yeasts, morels, truffles, and many molds.

  • Reproduce using ascospores inside sac-like structures called asci.

Basidiomycota

("club fungi")

• Includes mushrooms, puffballs, rusts, and smuts.

• Produce spores on club-shaped basidia.

Fungi are more closely related to animals than to plants

Are Fungi More Closely Related to Plants or Animals?

heterotrophic decomposers

Fungi are _______ that absorb nutrients

Saprotrophs, Parasites, and Mutualists

Three main feeding strategies of Fungi

Saprotrophs

Decomposers that break down dead material

Parasites

Absorb nutrients from a living host, often harming it

Mutualists

Live in beneficial relationships with other organisms (e.g., mycorrhizae with plants)

Fungal Hyphae

Long, thread-like structures that make up the fungal body

Absorb nutrients and form mycelium,

Role of Fungal Hyphae

Mycelium

A network which spreads out to maximize surface area for nutrient absorption

Fungi produce both sexually and asexually

Do Fungi Reproduce Sexually or Asexually?

Asexually Reproduction in Fungi

Fungi produce spores through mitosis (clonal reproduction)

Sexual Reproduction in Fungi

Involves fusion of two compatible hyphae from different mating types

Plasmogamy

Fusion of the cytoplasm of two different fungal cells, but nuclei remain separate (produces a heterokaryotic or dikaryotic stage)

Karyogamy

Fusion of nuclei, forming a diploid zygote.

• This is usually followed by meiosis, which produces haploid spores

Decomposers, symbiotic relationships, pathogens, food and medicine

Why Are Fungi Important in Ecosystems?

Lichens

A symbiotic relationship between a fungus (usually Ascomycota) and a photosynthetic partner (green algae or cyanobacteria)

Mycorrhizae

A mutualistic association between fungal hyphae and plant roots