Bio Exam II.3 Ascomycota

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  1. What are the different types of ascocarps? and size, if applicable.
    • apothecium
    • perithecium (3-4 mm long)
    • cleistothecium (microscopic)
  2. What do apothecium contain?
    In apothecium, where will you find one?
    asci and paraphyses

    • where you will find asci are the inner surface of the cup to form a hymenial layer
    • What you find in between are asci are hyphae that are sterile; will not produce asci at all
  3. What is the most common yeast?

    What is the life cycle?
    Saccaromyces cerevisiae

    diplobiontic (alternation of generations) [same life cycle that terrestrial plants have]
  4. What is the life cycle of Saccaromyces cerevisiae?
    young ascus--> ascus (containing ascospores)--> forms two different cells (n+ and n-)--> the cells bud--> fusion occurs between the cells--> conjugation--> one cell that becomes n+n--> the two nuclei fuse--> budding--> meiosis--> young ascus
  5. Explain the ascus.
    it has ascospores with a cytoplasm surrounded that forms a wall
  6. What do - and + indicate?

    What do the adult cells do?

    In the n+n cell, how many nuclei are there?

    What is a bud?
    the two types of cells

    act as gametes

    two nuclei

    a tiny cell that develops as a result of reproduction
  7. True or False:

    Both haploid and diploid divide by mitosis. 

    Explain mitosis.

    What is common?

    mitosis doesn't care about the chromosome amount

    several haploid and diploid are similar to plants
  8. Explain yeast?
    the cells will spring together under ideal conditions to produce filaments
  9. What are hyphae with only a single nucleus?
  10. How do asci develop?
    the nucleus divides before this

    • -Tip of the cell enlarges
    • - Two nuclei fuse (half red/ half black)
    • - 8 is a common number in building the walls and the spores get shot out of the ascus
    • - germinates; new mass
    • add more here!!!
  11. The vast majority of ascomycota are __, but some are __ and is dangerous.
    • saprophytes
    • parasites
  12. If a tree is infected by a fungus, what can happen?

    the fungus can travel through the root grafts

    because it has an extensive root system; when they meet, they form grafts
  13. How are ascomycetes beneficial?
    Saccaromyes species: baking and brewing industry; research in genetics and metabolism; used industrially to make hepatitis vaccine, ethanol for biofuel

    • Some are eaten directly:
    • - morels and truffels
  14. Explain morels and truffles?
    • morels: at least six species in N. America; each depression (apothecium)
    • truffles: two basic types: black and white
    • ascocarp completely underground; depends on animals for spore dispersal
  15. Economically, the __ was an important tree. What happened to it?
    american chestnut

    it was killed by chestnut blight
  16. Why are they not beneficial?
    some species of yeasts cause human diseases (ex: candidiasis, such as thrush)

    chestnut blight (Cryphonectria parasitica)

    Dutch elm disease

    Ergot of Rye

    Dogwood Anthrachose
  17. Chestnut blight
    - has done what? 
    - explain chestnut wood and its uses
    • wiped out mature chestnut trees in N. America
    • chestnut wood was very resistant to decay, so was important as lumber; used for heavy construction, roofing shingles, paneling, furniture, musical instruments, split rail fences, telephone poles, railroad ties

    eaten by people and animals
  18. Chestnut blight continued

    - spores

    - what does the fungus not do?
    spores of the fungus carried into teh US on Japanese chestnut trees imported around 1904 or earlier; disease first seen in NYC; by 1950, alomst all mature trees esast of the Mississippi were dead; fungus does not kill the roots, so new shoots may form
  19. Chestnut blight continued

    - __ produces a toxin that kills the __ and the __.

    Restoration: Explain

    • phloem
    • vascular cambium

    • there have been some successes
    • 1) breeding of resistant varieties using the Chinese chestnut
    • 2) genetic engineering of the fungus so that its less virulent and thwarts the more virulent strain
  20. What is related to chestnut blight? What does it do?
    • dogwood anthrachose: related to chestnut blight
    • destroys dogwood
  21. Dutch Emn disease
    -compared to chestnut blight?
    has not been as devastating as chestnut blight (affects American elm, a popular tree in towns and yards

    symptoms: leaves begin to wilt, turn yellow, then brown, then drop off tree; fungal spores and tyloses interfere with water movement through the xylem

    -first introduced into US in early 1930s on wood from Europe; originated in Asia; first foundin Ohio and seen as far west as Nebraska by 1935; reached CA by the 1970s
  22. Dutch elm disease cont:
    - economic use of elm
    -spread of fungus
    mainly used as shade trees

    spread: european and native elm bark beetle; root grafts between trees
  23. Explain in detail the spread of the fungus?
    fungus starts to grow in the xylen at the top of the tree; tends to grow in the water conducting cells; the fungus forms outpockets (tyloses) in the water conducting areas --> tyloses (outpocketing of parenchyma cells that plug xylem vessels)--> because tehre are pores in the tubes, parenchyma can go in and block water flow
  24. Dutch elm disease cont...

    control: Most methods control the __, not the __.
    • beetles
    • fungus

    • 1) insecticides
    • 2) sanitation: destruction of all dead and dying wood (bark beetles breed in dead wood)
    • 3) firewood control: may allow elm bark beetles to overwinter
    • 4) destroy root grafts: but barrier between diseased and healthy trees by severing or killing roots between the trees
    • 5) fungicides: can be injected into the trunk of affected trees or healthy trees (preventative treatment)
  25. Ergot of rye (Claviceps purpurea): Disease of rye (a grass)
    -fungus does what?
    -product does what?
    • fungus replaces rye grains with a dark purple stony mass of cemeted hyphae called a sclerotium
    • -the sclerotium produces at least 12 different alkaloids
  26. Ergot of rye cont.
    - disease of humas and animals
    - alkaloid use?
    • disease of humans and animals that eat sclerotia (ergotism (St. Anthony's Fire, Holy Fire)
    • ---symptoms: convulsions, burning sensation in arms and legs, gangrene, hallucinations death

    • - manky of the alkaloids are used medicinally
    • ---ones cause convulsions: used to induce labor in childbirth
    • ---ones causing gangrene: used to stop hemorrhaging (especialyl after childbirth)/ used to treat headaches and migrains (ergotamine)
    • source of lysergic acid (LSD)
  27. Ergot of rye cont.
    - holy Fire or St. ANthony's fire
    - responsible?
    aroud 1039, an outbreak occurred in France. A hospital was built to treat patients with ergotism. Eventually, monks started the order of St. Anthony

    responsible for the "witches" in Salem, MA in the 1600s (similar symptoms that could be misconstrued as witchcraft)
  28. What does ergotism not do?

    Documented epidemic? 

    1600s in MA?

    __ are the only part to produce these symptoms. It contains __. 

    Used to treat __. 

    It can be both __ and __.
    doesn't kill the plant, it decreases their productivity

    1944-45" Aquitanes of France

    1600: climate was perfect for rye to grow



    detrimental/ beneficial
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Bio Exam II.3 Ascomycota
2014-03-04 23:17:17
Plant Kingdom
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