PATH 3010 Study Guide Exam 1
• Mycology – The study of fungi
Characteristics of fungi:
• Fungi lack chlorophyll and are heterotrophic.
• They don’t engulf or digest their food but instead absorb it.
• They are eukaryotes, and they have cells with nuclei.
• They have unique cell wall chemistry – they have chitin and beta glucan in their cell walls.
• They are simple and made of tubular cell – hyphae.
• They reproduce by spores.
• They can reproduce sexually or asexually.
• Sequencing DNA helped to classify fungi. Before this they were categorized on their reproductive structure appearance.
• Myxomycota – slide molds – have no cells walls and engulf their food. They are not fungi.
• Water molds – have cellulose and flagella. This caused the Irish potato famine. They are not fungi.
• Microsporidia and Cryptomycota are newer additions to the fungi group.
How fungi start to grow:
• You have a spore with a nucleus.
• It arrives at a new substrate where there is water and will germinate. • It needs water.
• It has a germ tube, once it grows longer than the spore it becomes a hypha. • Many grow and it becomes a mycelium.
• The outer ring of growing fungi is the youngest part, because fungi grow outwards radially. Don't forget about the age old question of What is national sovereignty?
Favorable conditions for fungi grow:
• pH 6-8
• high humidity.
• Some are anaerobic, but most need oxygen.
Causes of spore production:
• Change in day length
• Less food Don't forget about the age old question of what is Circumpolar?
• Change in moisture
• Q: Which organisms are most closely related to the fungi?
• A: Flies and humans (animals)
• Fungus enzymes are good at attacking cellulose, lignin, and pectin.
• Cellulose – polymer that makes cell wall
• More woody plants like switchgrass have lignin
• Pectin helps to glue everything together.
• Fungi don’t require energy or toxic chemicals to break down compounds. • Companies are starting to use fungal enzymes to save cost and prevent waste. • Their enzymes can help to break down lignocellulose for conversion to bioethanol.
• It is believed that fungi helped plants come to land by providing nutrients to them. • The age of fungi: 400-500 million years ago.
• Q: Out of the 1.5 to 5.1 million fungi estimated to inhabit our plant, approximately what percent have been described?
• A: Less than 10%
• The species name includes the Genus and it is italicized.
Organism (fungus) of interest
Binomial Nomenclature Species Plantarum
First major mycologist
Mushrooms If you want to learn more check out Victimology is the study of what?
3 volume book
Lewis de Schweinitz
N. American patron saint of fungi
Named thousands of woodrot fungi
Criticized over naming of fungi
Created museum/library with brother
UGA professor 40 yrs.
Named many plant pathogenic fungi.
• The International Code of Botanical Nomenclature is revisited every 4 years and changed.
The International Code of Botanical Nomenclature rules:
• For each species there I only one name.
• The first description of a new fungus must be in Latin or English and in printed or electronic form.
• Whoever published a scientific article first could name the organism. • “Type” specimen must be designated.
• The first citation in literature must include the author’s name.
Reasons for changing a name:
• A sexual stage or older name was discovered.
• The fungus was misidentified.
• New genetic code reclassified the fungus. Don't forget about the age old question of An enzyme that breaks down disaccharides and trisaccharides is called what?
• Two different species are grouped together.
• A group of species is broken up.
• Internal transcribed space - ITS – the region that’s sequenced the most in fungi. • The spacer regions are good, because they are highly conserved.
• Q: Which is the most common form of spore dispersal?
• A: Wind
• Wind is a passive dispersal mechanism.
• Mold on fruit is dispersed by wind.
• These can survive in the air for years.
• They travel very long distances by wind.
• They are specific to wheat.
• Every year it starts near Mexico and spreads up to Canada.
• Since it is very specialized, it produces many spores. We also discuss several other topics like How elements involved in learning are labelled/classified when studying each form of behavior?
• They receive aid from rain and animals for dispersal.
• If you inhale these, you can damage your lungs.
• Lycoperdonosis: can get into small crevices in your lungs and get stuck. • Grow on organic matter.
• Mushrooms are “perfectly” designed for wind dispersal.
• The cap caused wind to travel faster through the bottom and slower on the top, raising the spores.
• Mushrooms produce spores on gills: more packed gill = more spores.
• Basidia – where the spores are produced and where meiosis happens to create 4 distinct nuclei.
• These are a result of sexual reproduction.
• You can pick them and carve into them.
• Mushrooms will grow and change direction in order for their undersides to face down. • Inky caps autodigest itself in order to break down the cap and release the spores.
• 4 spores = meiosis.
• 8 spores = mitosis.
• Asci have a high concentration of mannitol that drive osmosis into them and causes dispersal.
Wind-dispersed spore characteristics:
• Many produced If you want to learn more check out what is Traditional biology?
• Long lived = dark, thick cell walls
• Short lived = colorless, thin cell walls
Gummy stem blight fungus:
• This infects watermelons, cucumbers, pumpkins, etc.
• If a couple get infected, it can spread very quick and is a problem because the food is usually grown near each other.
• Aero-aquatic fungi float on the top of the water.
• When leaves fall they will grow through them, the leave will sink, and the fungi can still survive under water.
• They contribute to the food web, by breaking down the leaves for other organisms.
• The flies get the spores all over them, eat them or carry them, and then disperse them when they fly somewhere else.
• This infects pines.
• It is a problem throughout the southeast where there are many pines. • This taste really good and attracts insects.
• The insects them act like pollinators.
• Bioluminescent fungi have luciferin pigment.