Fungi

1. Fungi Eukaryotic Organisms

2. Fungi • Mycology: The study of fungi. • Fungi: A diverse group! Can be… • Heterotrophic: Any organism that cannot synthesize its own food. • Saprophyte: Any organism that derives nourishment from dead or decaying matter. • Parasite: Any organism that obtains nutrients from the tissues of another organism it lives in or on. • Most are multicellular, complex organisms. • Yeast: A variety of unicellular, fermenting fungi.

3. Fungi Anatomy • Cell Walls: Some fungi have cellulose walls, but most have chitin (a polysaccharide). • Chitin is also found in exoskeletons! E.g., ticks & spiders. • Enzymes: Lysosomal enzymes are found in all fungi & digest damaged cells & aid in host invasion.

4. Fungi Anatomy • Pileus aka Cap: The horizontal portion of a mushroom containing the lamellae, tubes, and scales. • Lamellae aka Gill: A radiating vertical plate on the underside of a mushroom cap of some mushrooms. • Scale: Thin, flat plates on the cap of a mushroom

5. Fungi Anatomy • Stape aka Stem: The portion of the mushroom that grows in the opposite direction of the roots and provides support for the above-ground portion of the fungi. • Annulus aka Ring: The growth ring or veil remnant on a mushroom stalk – surrounds the stem of a mature mushroom. • Volva aka Cup: A membranous envelope enclosing the base of various mushrooms.

6. Fungi Anatomy • Mycelium: A loosely organized mass of hyphae. • Stays embedded in decaying organic matter, soil, or living tissues. • Mycelial cells release the enzymes that digest the substratum (surface the fungi is growing on) & absorbs small molecules. • Hyphae: Threadlike structures that combine to form the mycelium. • Hyphal cells are typically have two nuclei. • Septa: The cross-wall structure that divides the two halves of the hyphal cells. • Septa allow cytoplasm & nuclei to pass between the cells.

7. Fungi Anatomy • Thallus: The body of fungi that has not differentiated into leaves, stems, roots, etc.

8. Types of Fungi

9. Edible Cultivated Mushrooms

10. Edible Wild Mushrooms

11. Medicinal Mushrooms

12. Poisonous & Psychotropic Mushrooms

13. Fungal Reproduction • Asexual Reproduction: Reproduction that does not involve the union of gametes or the exchange of genetic material. • Conducted through Mitosis or Binary Fission. • Sexual Reproduction: Reproduction that involves the union of gametes and the exchange of genetic material. • Conducted through Meiosis. • Fungi can reproduce both sexually and asexually. • A few ONLY reproduce asexually. This includes yeast!

14. Asexual Reproduction – Mitosis • Mitosis: The process of cell division resulting in two identical daughter cell produced from a single parent cell. • Prophase: The chromatin within the cell condenses into chromosomes and divides. • Metaphase: The chromosomes align at the equitorial plate & attach to the cell wall & centromere via the mitotic spindle. • Anaphase: The centromere divides, splitting the chromosomes. The chromosomes migrate to opposite poles. • Telophase: The cell membrane pinches inward, dividing the cytoplasm, & splits into two complete cells.

15. Asexual Reproduction – Binary Fission • Binary Fission: A method of asexual reproduction very similar to mitosis. • DNA of the mother cell replicates & joins into circular pairs. • The circular pairs attach to the cell membrane/plasma membrane. • The cell elongates, forcing the paired chromosomes separate. • The cell membrane invaginates (pinches inward toward the middle). • When the cell membrane has completed invaginating, the cell splits off into two identical daughter cells. • It is fairly common for one of the daughter cells to not be identical to the mother cel.

16. Sexual Reproduction – Meiosis • Meiosis: A method of sexual reproduction where germ cells (such as eggs and sperm) are produced. • The total amount of genetic material in the daughter cells is reduced during division. • 4 daughter cells with a single set of chromosomes is produced. • The cell must join with another daughter cell with a second set of chromosomes to divide into a new organism.

17. Sexual Reproduction – Meiosis • First Division of Meiosis: • Interphase: Genetic material duplicates. • Prophase 1: The duplicated genetic material condenses and pairs off, then may go through “crossing-over” to exchange segments between the chromosomes. • Prometaphase: Nucleus dissolves and mictrotubules attach to the genetic material. • Metaphase 1: The chromosomes align at the equitorial plate. • Anaphase 1: The chromosome pairs separate, sister chromatids remain together. • Telophase 1: Two daughter cells are formed with one chromosome each.

18. Sexual Reproduction – Meiosis • Second Division of Meiosis: Gametes are formed. • Prophase 2: DNA does not replicate • Metaphase 2: Chromosomes align at the equatorial plate. • Anaphase 2: Centromeres divide into 23-chromosome sets & sister chromatids migrate to opposite poles. • Telophase 2: Complete cell division begins. . • Cytokinesis: 4 haploid daughter cells are produced, each with 23 chromosomes.

19. Fungi in the Ecosystem • Facultative Parasite: An organism that can obtain nutrients from nonliving organic matter or from living organisms. • Fungi don’t have to be parasitic, but can be if given the opportunity. • Beneficial Behaviors: • Act as decomposers. • Some fungi produce antibiotics to inhibit the growth of bacteria or kill the bacteria outright. • Penicillin is produced by a fungi from the ascomycota group called a sac fungi.