blastic vs thallic development

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blastic vs thallic development
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Characteristics of Molds

• 3 types of conidia text pg 998
• 1. arthroconidia formed by septa formation of (
  fragmentation from) existing hyphae - they
  fragment at a septum or joint
• 2. blastoconidia oval budding cells of yeast -
  asexual propagules produced by softening and
  blowing out of hyphae or conidiophores
• 3. chlamydoconidia formed within the vegetative
  hyphae
• - asexual propagules that result from thickening
  and rounding up of cells between two septae
  (chlamydospore is used to describe these
  diagnostic structures of Candida albicans)

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Thallic Conidia
??? ?
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Characteristics of Molds

• Some asexual propagules are categorized by their
  conidiogenous cell - text pg 998
• Phialides produce phialoconidia in succession
  from base without increasing in width or length -
  has a general bowling pin shape see Fig
  19-13, pg 1004
• Annelides produce anneloconidia in succession
  from base by a series of short percurrent
  proliferations - annellide increases in length
  and becomes narrower as each subsequent conidium
  is formed connidia leave circular scars as they
  elongate
• Debbie?

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Phialoconidium
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Anneloconidia
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Characteristics of Molds

• Sporangiospores (Zygomycetes) are asexual
  propagules that develop by cleavage within a
  sac-like structure called a sporangium (sporangia
  is pleural for sporangium)
• Sporangia are connected to hyphae by lateral or
  terminal extensions called sporangiophores
• True spores (sporangiospores, zygospores,
  ascospores, basidiospores) reproduce by cleavage
• Conidia are therefore not true spores Zygo has
  the only true asexual spore type

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Conidiophore
Conidium
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Characteristics of Molds

• Sexual reproduction occurs when two haploid cells
  (those cells produced during meiosis) from two
  mating types fuse to form one diploid cell
• The diploid cell undergoes cleavage and produces
  a new multicelled individual
• See figures on pg 999

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Characteristics of Molds

• Molds that have transparent mycelium are called
  hyaline molds
• Molds that have dark brown, green, or black
  mycelium are called dematiaceous molds
• Hyaline molds can have colored fruiting bodies
  which give them an overall colored appearance
• Debbie?