1. Chapter 31
Fungi

2. General characteristics of Fungi
eukaryotic
mostly multicellular; some unicellular
cell walls made of chitin (animal feature)
usually filamentous bodies (filaments called hyphae)
external heterotrophs; principal decomposers
exhibit nuclear mitosis
reproduce sexually or asexually
Examples:
Amanita muscaria - mushroom (p. 604)
Penicillium and Aspergillus (p. 613)
Rhizopus stolonifer (black bread mold) (p. 609)
yeasts ex: Saccharomyces cerevisiae (p. 611)
Candida - cause of thrush
pathogens that cause athlete’s foot and ringworm
Treatment of fungal diseases is difficult because of their similarity to animals

3. Structure and function of hyphae
hyphae - the filaments of a fungus
mycelium - tangled mass of hyphae
*** large surface area, therefore good
absorption of food
septa - dividing walls in a hypha
Nutrition: All fungi digest food outside their bodies (external digestion).
*** Important decomposers
*** Can compete for our food
Body of fungus is a mass of hyphae which is separated by walls called septa. Mass of connected hyphae is called mycelium. Cytoplasm flows throughout the hyphae passing through pores thus food gets transferred throughout the hyphae.

4. Mitosis divides nucleus and not hyphae
Some hyphae have one nucleus – monokaryotic
Some hyphae have two nuclei – dikaryotic
During Mitosis, nuclear envelope does not break and reform.
Spindle apparatus is formed within the nucleus by spindle plaques (centrioles are absent)
Secrete digestive enzymes and absorb organic molecules – external digestion

5. Five main groups of Fungi
Fig. 31.6
Five main groups of Fungi
Deuteromycetes-Imperfect fungi lack phylogenetic position, no sexual reproduction and less data to support its relation to fungi

6. Various groups of Fungi
Chytridiomycetes are closely related to ancestors of early fungi
Aquatic fungi with flagellated zoospores
Glomeromycetes (asexual plant symbionts) form intracellular associations with plant roots called arbuscular mycorrhizae.
No sexual reproduction
Possible role in evolution of terrestrial plants

7. Zygomyetes: produce zygotes, example Rhizopus – (grows on bread)
Meiosis (sexual)– Zygosprangium forming zoospores
Mitosis (asexual) – sporangiophores form sporangia

8. Ascomycetes: The Sac (ascus) fungi
Members are bread yeasts, common molds, morels, cup fungi and truffles.
Plant pathogens are Cryphonectria parasitica – chestnut blight
Ophiostoma ulmi – Dutch elm disease
Penicillium and Aspergillus genera (Deuteromycetes)
Candida milleri – sourdough bread
Saccharomyces cerevisiae- wine preparation

9. Meiosis – Ascocarp forming four haploid daughter nuclei
Mitosis-Ascospores with eight daughter nuclei that release conidia

10. Basidiomycetes: The club (Basidium) Fungi
Members include Mushrooms, toadstools, puffballs, jelly fungi, and shelf fungi
Pathogens – Rusts and smuts
Some mushrooms can be deadly poisonous

11. Meiosis results in basidium - basidiopsores

12. Range of Symbioses Obligate Symbiosis – essential for survival
Facultative Symbiosis – the fungus can survive without host
Parasites and Pathogens gain resources from host and kill it
Commensal – one partner is benefited but neither is harmed
Mutualistic relationship – both are benefited
Endophytic fungi live inside plants and protect them from parasites

13. Mycorrhizae Mycorrhizae are fungi associated with roots of plants
Fungi aid in transfer of P, Zn, Cu and other mineral nutrients from soil into roots
Plant provides organic carbon to fungus
Arbuscular Mycorrhizae- the hyphae penetrates into the roots and into the surroundings of the plant
Ectomycorrhizae – the hyphae do not penetrate the root and only surround it

14. This project is funded by a grant awarded under the President’s Community Based Job Training Grant as implemented by the U.S. Department of Labor’s Employment and Training Administration (CB ). NCC is an equal opportunity employer and does not discriminate on the following basis: against any individual in the United States, on the basis of race, color, religion, sex, national origin, age disability, political affiliation or belief; and against any beneficiary of programs financially assisted under Title I of the Workforce Investment Act of 1998 (WIA), on the basis of the beneficiary’s citizenship/status as a lawfully admitted immigrant authorized to work in the United States, or his or her participation in any WIA Title I-financially assisted program or activity. “This workforce solution was funded by a grant awarded under the President’s Community-Based Job Training Grants as implemented by the U.S. Department of Labor’s Employment and Training Administration.  The solution was created by the grantee and does not necessarily reflect the official position of the U.S. Department of Labor.  The Department of Labor makes no guarantees, warranties, or assurances of any kind, express or implied, with respect to such information, including any information on linked sites and including, but not limited to, accuracy of the information or its completeness, timeliness, usefulness, adequacy, continued availability, or ownership.  This solution is copyrighted by the institution that created it.  Internal use by an organization and/or personal use by an individual for non-commercial purposes is permissible.  All other uses require the prior authorization of the copyright owner.”