PLP 150C1 1st EditionExam 3 Study Guide: Lectures 14 - 18Lecture 14What are Tricothecenes?Very nasty toxins produced on moldy grainAs humans, which toxin are we most commonly exposed to?Alternaria toxinsWhere are Alternaria toxins commonly found?Fruits and vegetables and processed foods.What is LD50? What is the measure dependent on?A measure of toxicity. The dose that kills 50% of animals tested. The measure is dependent upon the animals and the means of exposure.What is locoweed toxic to? What is locoism?Locoweed is toxic to livestock. Locoism is when animals exhibit depression, difficulty walking, lack of muscular coordination, difficulty eating & drinking – due to exposure.What are microbial properties?Properties that aid in competition against other microbes living in microbial film that covers everything on the planet.True or false? Some types of Penicillium contaminate apple juice and apple sauce.True.Lecture 15What did Alexander Fleming discover?PenicillinTrue or false? Fleming finally found Penicillin after searching for it for three years.False. He was studying Staphylococcus, when he accidentally found Penicillin.What was Fleming’s first impression about his Penicillin discovery?He thought he didn’t think it would be able to treat internal infections. He thought it could be used on wounds, and other external injuries.What are most famous antibiotics made by?Filamentous bacteria known as Actinomycetes, or Actinobacteria.What is Mycophenolic acid used for?Transplant patients to suppress rejection of transplanted organs, usually kidneys.Where do most antifungal medicines come from?Bacteria.True or false? Plants have difficulty defending themselves against fungi.False. Plants have a long history of defending themselves against fungi.Lecture 16What do prototaxites represent?One of the oldest life-forms on this planet.What are prototaxites made of and what are they used in?Made of motile cell & flagellum. Used in architecture. What is histoplasmosis?An infection transmitted by airborne spores that you breathe in when you work around soil.Which people does histoplasmosis usually affect, and what part of their body?Farmers, landscapers, construction workers, etc. It affects their lungs.What is blastomycosis?A rare fungal infections caused by an ascomyceteWho does blastomycosis usually affect, and how?Usually affects hunting dogs, because the fungus spread by inhalation.Describe Coccidiodimoycosis (valley fever).Caused by an ascomycete, and the disease is usually mild. The symptoms are flu-like, and usually rashes develop. Rodent cadavers spread it.Name three common skin infections.Ringworm, athlete’s foot & jock itch.True or false? Candida is a disease that should be reported right away, because it is so difficult to treat.False. Candida is healthy to have on us; it keeps other things in check. True or false? Subcutaneous and invasive mycoses are rare, and hard to treat.True. It’s really rare and hard to treat.Lecture 17Who first discovered invertebrate-trapping fungi?Drechsler.What are some examples of fungi indirectly interfering with nematode survival?1. Fungi kill with mycotoxins2. Destroy nematode feeding sites3. Compete for food to reduce nematode multiplication4. Mycorrhizal fungi improve health of nematode-infected plants & may also restrict nematode development.What are some examples of fungi directly parasitizing nematodes?1. Fungi use their trapping structures to literally trap them.2. Facultative parasitic fungi attack sedentary stages of nematode3. Endoparasitic fungi obligate parasites.Describe Caternaria, an endosymbiont of nematodes.No hyphal structures. The fungal evacuation tubes are outside the nematode.What are three traits that fungal symbionts of insects share?1. Chitin2. High reproductive rate3. Important role in recycling organic compoundsLecture 18What are lichens?Composite organisms consisting of a symbiotic association of a fungus with a photosynthetic partner.What do lichens give algae?Water & mineralsWhere do lichens occur? Give examples.Extreme environments, like arctic tundra, hot deserts, rocky coasts, etc.What have lichens been used for?To make dyes, perfumes and traditional medicines.In some cases, what do epiphytes & endophytes represent?Latent infections.What are mycorrhizal fungi the key to?Plant health & their ability to grow in varied soils.What are fungi particularly good at decomposing?Plant matterWhat are the four cell wall components?Cellulose, hemicellulose, pectin and