Chapter 22 Fungi

What are Fungi? Fungi have threadlike bodies. Fungal cell walls contain chitin. – Chitin – a tough carbohydrate that is also found in the hard outer covering of insects and other organisms. Fungi are heterotrophic.

Structure and Function A typical fungal body is made of filaments that allow the fungus to have a large surface area to absorb nutrients efficiently.

Body Structure Hyphae – a filament of a fungus. – The cells of hyphae are haploid, are almost identical, and generally perform the same functions. Mycelium – the mass of fungal filaments that forms the fungal body Rhizoids – root-like structures sometimes formed by hyphae.

Obtaining Nutrients Fungi that absorb nutrients from dead organisms = saprobes *Fungi that absorb nutrients from living hosts are called parasites.

Reproduction In sexual reproduction, spores are produced by meiosis. In asexual reproduction, spores are produced by mitosis. Sexual Reproduction – Occurs when hyphae from one fungus fuse with hyphae from a fungus of the opposite mating type. Asexual Reproduction – Spores are produced at the end of specialized stalks that have been produced by specialized hyphae.

Yeast and Mold Yeast – Species of fungi that exist primarily in a unicellular state. – Usually reproduce by budding. – Under very specific conditions may produce sexually. Mold – Rapidly growing, asexually reproducing stage of some fungi. – “mold” refers only to the asexual phase.

Assignment Pg 523, 1-5. Write out the question and the answer for all of these assignments. Read pg and do pg. 528, 1-5. Read pg and do pg. 531, 1-6. Do pg. 535, Pg. 536, #25. and Pg. 537, 1-11 all. (Due on Friday, 5/7 at the beginning of the hour)