The Kingdom Fungi Photo Credit: ©D. Cavagnaro/DRK Photo

What Are Fungi? Eukaryotic heterotrophs with cell walls. contain chitin, a complex carbohydrate.

What Are Fungi? Fungi depend on other organisms for food. They digest food outside of their bodies and then absorb it. Extracellular digestion Some fungi absorb nutrients from decaying matter in the soil. Mutualism (both species benefit) Other fungi are parasites, absorbing nutrients from their hosts.

Structure and Function of Fungi Except for yeasts, all fungi are multicellular. Fungi are made up of thin filaments called hyphae. Each hypha is only one cell thick.

Structure and Function of Fungi In some fungi, cross walls divide hyphae into cells with 1 or 2 nuclei. In the cross walls, there are openings through which the cytoplasm and nuclei can move. Most fungi are made up of filaments called hyphae. In some fungi, the hyphae are divided by cross walls.

Structure and Function of Fungi Some hyphae lack cross walls and contain many nuclei. Most fungi are made up of filaments called hyphae. In some fungi, the hyphae lack cross walls and contain many nuclei.

Structure and Function of Fungi Fungus Structure  The bodies of multicellular fungi are composed of many hyphae tangled together into a thick mass called a mycelium. This permits a large surface area to absorb food from the environment.

Structure and Function of Fungi Structure of a Typical Fungus The body of a mushroom is part of a mycelium formed from many tangled hyphae. The major portion of the mycelium grows below ground. The visible portion of the mycelium is the reproductive structure, or fruiting body, of the mushroom.

Structure and Function of Fungi Fruiting Body reproductive structure growing from the mycelium in the soil beneath it. A mushroom is the fruiting body of a fungus. Fungi reproduce by budding, fragmentation, or releasing haploid spores

Fungi Reproduction Spores form 2 Ways: Sexually B. Asexually

Fungi Reproduction Sexual reproduction involves two mating types: “+” (plus) and “–” (minus). Hyphae of opposite mating types meet and fuse, bringing “+” and “–” nuclei together in one cell.

Fungi Reproduction After growth and development, the nuclei form a diploid zygote nucleus. The zygote enters meiosis and produces haploid spores. These spores are capable of growing into new organisms.

Fungi Reproduction Asexual reproduction occurs when hyphae break off and begin to grow on their own. Some fungi produce spores, which scatter and grow. Spores are produced in structures called sporangia. Located at tips of specialized hyphae called sporangiophores.

Classification Fungi are classified according to their structure and method of reproduction. The four main groups of fungi are: Common molds (Zygomycota) Sac fungi (Ascomycota) Club fungi (Basidiomycota) Imperfect fungi (Deuteromycota)

Zygospore Fungi Phylum Zygomycota Produce spores on stalks called sporangia Black bread mold Live off plant and animal remains and baking goods in the kitchen

Sac Fungi Phylum Ascomycota Cup fungi, morels, and truffles Produce spores in microscopic sacs Yeasts are unicellular sac fungi Reproduce asexually by budding. Become active in a moist environment.

Club Fungi Phylum Basidiomycota Usually reproduce sexually Produce fruiting bodies (mushrooms) Basidia line the gills

Imperfect Fungi Phylum Deuteromycota No sexual reproduction Penicillin, bleu cheese, athlete’s foot

All Fungi Are Heterotrophs Fungi rely on other organisms for energy. Saprobes Organisms that obtain food from decaying organic matter. Parasites Harm other organisms while living directly on or within them. Symbionts Live in close and mutually beneficial association with other species.

Symbiotic Relationships Lichens  Lichens are symbiotic associations between a fungus and a photosynthetic organism. Typically either a green alga or a cyanobacterium, or both.

Symbiotic Relationships Structure of a Lichen Lichens are a mutualistic relationship between a fungus and an alga or a cyanobacterium, or both. The protective upper surface of a lichen is composed of fungal hyphae. Below this is the layer of cyanobacteria or algae with loosely woven hyphae. The third layer consists of loosely packed hyphae. The bottom layer is a protective surface covered by small projections that attach the lichen to a rock or tree.

Pros and Cons Antibiotic (penicillin) Decomposers Some are symbiotic with algae (lichen) or plant roots (nitrogen fixation) Baking, brewing, food Yeast have been used for molecular research Fugal diseases include ring worm and athletes foot. Fungi can attack and destroy crops.