Chapter31[1] - Chapter 31 Fungi I Introduction What are Fungi a 80,000 identified species so far b Eukaryotes c Single or multi-celled(branching

Info iconThis preview shows pages 1–3. Sign up to view the full content.

View Full Document Right Arrow Icon
Chapter 31: Fungi I. Introduction: What are Fungi? a. 80,000 identified species so far b. Eukaryotes c. Single or multi-celled (branching networks of multicellular filaments) d. Terrestrial e. Heterotrophs, Decomposers i. without fungi, the Earth would be piled high with dead trees ii. only fungi and a few bacteria are capable of digesting both cellulose (in plant cell wall) and lignin (in wood) f. Parasites (athlete’s foot, yeast infection), mutualists II. Why Do Biologists Study Fungi? a. Fungi Provide Nutrients to Land Plants i. Fungi + plant root = mycorrhizal association b. Fungi Speed up the Carbon Cycle on Land i. Decomposers and recyclers ii. Saprophytes (eat dead plant material) iii. During Carboniferous Period 1. few fungal fossils (high acid environment) 2. An increase in peat and coal production because plants were not broken down. iv. at the end of the Permian Period (250 mya) 1. greatest mass extinction of all time 2. brief increase in fungal fossils 3. thought that massive die-off of trees provided rotting wood and a favorable environment for fungi. v. Fungi complete carbon cycle by breaking down dead/rotting organisms c. Fungi Have Important Economic Impacts i. Some (a very few) are pathogenic ii. Some produce antibiotics iii. Impact on crop production and storage iv. Impact on food industry 1. mushrooms are eaten 2. food production using fungi: bread, soy sauce, tofu, cheese, beer, wine, whiskey v. Impact on environment 1. pathogen to certain trees (chestnut blight) Dutch elm disease d. Fungi are key model organisms in Eukaryotic genetics i. Neurospora (one gene, one enzyme) ii. Saccharomyces – model for eukaryotic cells (easy to grow in lab) III. How Do Biologists Study Fungi? a. Direct sequencing b. Analyzing morphological traits (only 2 growth forms) i. Single-celled = yeasts ii. Multi-celled, filamentous = mycelia 1. dynamic: grow out and die back with changes in food supply 2. can become very large (1310 acre organism in Oregon) 3. hyphae (individual filaments of mycelium) a. haploid (some are heterokaryotic (2 haploid nuclei) b. hyphae are very thin tubes. This thinness increases surface area to volume ratio and increases the absorption potential, while
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
unfortunately increases the risk of drying out as well. (must live in moist environment) c. most contain septa (cross walls) with gaps to allow for the flow of nutrients, organelles, even nuclei (due to this flow, fungi are sometimes thought of as an intermediate between a multicelled organism and a large unicellular organism) d. those without septa (coenocytic = common celled), and act like an enormous single-celled organism 4. Reproductive structures (define 4 major groups) Fig 31.7 a. Thick fleshy structures i. Exposed to air ii. Do not absorb food (though they arise from mycelia and have hyphae) b. Mycota = fungus Group Aka Reproduction Special trait
Background image of page 2
Image of page 3
This is the end of the preview. Sign up to access the rest of the document.

This note was uploaded on 11/11/2009 for the course BLY 459 taught by Professor Obrien,j during the Spring '08 term at S. Alabama.

Page1 / 6

Chapter31[1] - Chapter 31 Fungi I Introduction What are Fungi a 80,000 identified species so far b Eukaryotes c Single or multi-celled(branching

This preview shows document pages 1 - 3. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online