What did Mr. Fungus say to Ms. Algae, when he proposed? I lichen you! Ch. 21 Fungi What did Mr. Fungus say to Ms. Algae, when he proposed? I lichen you!

Ch. 21 Outline 21-1: The Kingdom Fungi 21-2: Classification of Fungi What are Fungi? Structure and Function of Fungi Reproduction in Fungi How Fungi Spread 21-2: Classification of Fungi The Common Mold The Sac fungi The Club Fungi The Imperfect Fungi

Ch. 21 Outline 21-3: Ecology of Fungi All Fungi are Heterotrophs Fungi as Decomposers Fungi as Parasites Symbiotic Relationships

What are Fungi Fungi used to be classified with plants, but they are actually very different than plants Fungi are eukaryotic heterotrophs that have cell walls Cell walls made up of chitin (Complex carbohydrate found in the exoskeleton of insects) Fungi do not ingest their food, they break it down outside their bodies by secreting enzymes. Then, they absorb it.

Structure and Function of Fungi All fungi are multicellular except for yeasts Hyphae: thin filaments that make up fungi. Some hyphae have cross walls in them (cell walls with openings in them) Hyphae have many nuclei in them

Hyphae Hyphae With Cross Walls Hyphae Without Cross Walls Nuclei Cell wall Cytoplasm Cross wall Hyphae With Cross Walls Hyphae Without Cross Walls

Structure and Function of Fungi The bodies of multicellular fungi are composed of many hyphae tangles together into a thick mass called a mycelium. This gives fungi a very large surface area to absorb nutrients. Fruiting body: reproductive structure growing from the mycelium Ex. The Part of the mushroom you see!

Fruiting Body and Mycelium Hyphae Mycelium

Reproduction in Fungi Most fungi reproduce both asexually and sexually Asexual  happens when a hypha breaks off and grows on its own or by the production of spores Spores: reproductive cell that is capable of growing into new organisms by mitosis alone Sprorangia: the structure that produce spores Sexual  two different fungi mate

How Fungi Spread Fungal spores are found in almost every environment. Ex. Mold grows everywhere it seems! Many spores are light and dry  easily scattered by wind. Others are dispersed by animals.

Classification of Fungi There are over 100,000 species of fungi. They are classified based on their structure and method of reproduction. Four main groups: Zygomycota (common molds) Ascomycota (sac fungi) Basidiomycota (club fungi) Deuteromycota (Imperfect fungi)

are divided into the phyla Concept Map Section 21-2 Fungi are divided into the phyla Ascomycota Zygomycota Basidiomycota Deuteromycota includes includes includes includes Common molds Sac fungi Club fungi Imperfect fungi

The Common Molds Zygomycetes are the molds you see on cheese, breads, and meat. They are characterized by the zygospore in their life cycle. Zygospore: resting spore that contains zygotes formed during the sexual phase of the life cycle. Rhizoid: root-like structure that anchors the fungi

Black Bread Mold FERTILIZATION Sporangium Gametangia Spores (N) Zygospore (2N) Spores (N) Sporangium + Mating type (N) Stolons Rhizoids - Mating type (N) Sporangiophore Gametangia FERTILIZATION MEIOSIS Sexual Reproduction Asexual Reproduction Diploid Haploid

The Sac Fungi The phylum Ascomycota is named for the ascus, a reproductive structure that contains spores. Ascospores: the spores produced in an ascus. Yeasts are an example of Sac Fungi. Uses of yeast: baking breads and brewing alcohol

Ascomycota Fruiting body (N + N) Hyphae (N + N) Ascus (N + N) Diploid Hypha (N) Conidiophore Conidia (N) + Mating type (N) - Mating type (N) 8 Ascospores (N) Ascus Zygote (2N) Ascus (N + N) Fruiting body (N + N) Hyphae (N + N) Gametangia Asci Hyphae (N) Diploid Haploid FERTILIZATION HYPHAE FUSE MEIOSIS Sexual Reproduction Asexual Reproduction

Ascomycota

The Club Fungi The Phylum Basidiomycota gets its name from a specialized reproductive structure that resembles a club. Basidium: the spore-bearing structure in Basidiomycota Example of club fungi: Mushrooms

Basidiomycota Fruiting body (N + N) Button Secondary mycelium (N + N) Primary mycelium (N) + Mating type (N) - Mating type (N) Basidiospores (N) Zygote (2N) Basidia (N + N) Gills lined with basidia Gills Stalk Base Cap FERTILIZATION HYPHAE FUSE Haploid Diploid MEIOSIS

The Imperfect Fungi Deuteromycota is an extremely varied phylum. It is composed of those fungi that are not placed in the other phyla because researches have never been able to observe a sexual phase in their life cycle. Example: Penicillin notatum (The Source of Penicillin)

All Fungi are Heterotrophs Many Fungi are saprobes: obtain their food from decaying organic matter. Others are parasites or symbiotes (live in beneficial relationships with another organism).

Fungi as Decomposer Fungi play an important role in ecosystems because they break down and recycle nutrients. They secrete enzymes outside of their hyphae and then absorb nutrients.

Fungi as parasites Parasitic fungi cause serious plant and animal diseases Ex. Athlete’s Foot

Symbiotic Relationships Some fungi form symbiotic relationships in which both partners benefit. These are often essential to the ecosystem. Lichens: association between a fungi and green algae or cyanobacteria. The algae/cyanobacteria provide the fungus with food (since they are photosynthetic) The fungus provides a large surface area to collect water and minerals Lichens can exist in extreme environments (drought, cold) and are many times the first to inhabit in an area.

Lichens

Symbiotic Relationships Mycorrhizae: The association of plant roots and fungi Plants provide the food (photosynthesis) Fungi increases the surface area for absorption About 80% of plants are in this type of relationship This association is essential for many plants to survive and reproduce

Mycorrhizae