Section 3.3 Fungus Kingdom

Basic Characteristics Cells are eukaryotic All cells are surrounded by a cell wall containing chitin, not cellulose like plants Most are multicellular (yeast are single-celled) Reproduction is sexual and asexual, by producing spores They are heterotrophs Many are stationary and anchored in the soil, but without true roots

Some fungi are decomposers and recyclers. Other fungi cause disease. (eg. Some moulds) Some are parasitic (eg. Wheat rust) Some form mutualistic relationships

Bread Mould, Yeast, Mushrooms

FUNGI Some fungi are decomposers and recyclers. Other fungi cause disease. (eg. Some moulds) Some are parasitic (eg. Wheat rust) Some form symbiotic relationships (a relationship where both organisms benefit).

Fungal Structures They have eukaryotic cells that DO NOT have chloroplasts Fungi have two major components: fruiting body and the mycelium Fruiting body is the spore producing reproductive structure

(b) Mycelium is a branched, net-like mass - it is made up of hyphae, a thin threadlike filament -The hyphae grow in and around a food source, secreting digestive enzymes and absorbing nutrients

Growth Cells grow at the tips only This allows them to colonize dead or living organic matter

Nutrition All fungi are heterotrophic and obtain nutrients from other organisms They obtain this nutrition by extra-cellular digestion THEN absorption; not by ingestion (like us)

There are four types of nutrition: Parasitic Predatory Mutualistic Saprobial Refer to pg 106 – find an example and describe what they do!

Reproduction Type I: Using Spores Fungi reproduce by spores, which are single cells surrounded by a wall Spores are carried by air currents to new sources where they give rise to new hypha Asexual reproduction: fungi produce spores by mitosis Sexual reproduction: fungi produce spores by meiosis

Type II: No Spores Without spores, fungi reproduce only asexually Budding (usually unicellular)– where the smaller cell develops while attached to the parent cell, then eventually pinches off. (ex. Yeast) (b) Fragmentation (usually eukaryotic) – where a piece of the pmycelium breaks and forms a new fungus

Five Phyla of Fungi They are grouped based on reproduction and the structure of their fruiting body made

Phylum Deuteromycota Do not reproduce sexually That is the only thing all species in this phylum have in common! Very diverse Ex. Peniciilium – makes pencillin

Phylum Zygomycota Most in this division are multicellular and terrestrial Hyphae break into the food source, and are then termed rhizoids Rhizoids draw water and sugar from the bread (or food source) thus allowing the mould to grow further After a few days, case-like structure called sporangia appear Each sporangia can produce several thousand spores

Example: bread mould (Rhizopus)

Zygomycota Cont’d When the sporangia break open, the spores are carried by the air to allow colonization of new areas. Under less favourable conditions, zygomycotes reproduce sexually Two hyphae form, which conjugate and produce a zygospore Zygospores stay dormant until growing conditions are correct

Phylum Ascomycota They produce saclike structures for reproduction Spores produced by sexual reproduction in these are termed ascospores, and are produced in a sac called an ascus. Examples: mildew, some moulds, some yeasts Recall: yeast reproduce via budding, which falls under this type of reproduction (pg108)

Phylum Chytridomycota They are the only fungi with swimming spores (with flagella) Most of them are saprophytes which means they obtain nutrients from dead organic matter.

Phylum Basidiomycota Under damp conditions, the mycelial mass form knobs which absorb water and grow quite large. These knobs become spore bearing structures and appear as caps. The caps have gills that have thousands of reproductive cells called basidia. Each basidium has several thousand spores. Examples: mushrooms, rusts, and puffballs

Homework What are lichens? (pg 109) Pg 110 #5, 6, 12, 14, 15