Practical #2 - Fungi

Question 1

Fungi Classifications

Answer 1

• Kingdom Fungi
  
  • ​Division Zygomycota
  • Division Ascomycota
  • Division Basidiomycota

Question 2

Common Characteristics Shared by Most Fungi

Answer 2

• Lack chlorophyll
• Most are multicellular
  
  • Yeasts are not
• Heterotrophic
  
  • Saprobic nutrient acquisition - secrete and digestive enzyme and then soak it back up
• Exists as free living saprobes or as symbionts
• Cell walls strengthened with chitin
• Mycelium is made of hyphae ​
• Zygotic life cycle
• Reproduce asexually

Question 3

What are the two types up hyphae?

Answer 3

• Aseptate - no cross walls between individual cells and nuclei
  
  • ​coenocytic
• Septate - one or two haploid muclei in each cell
  
  • Septa are cross walls hat are complete

Question 4

What are spores in Fungi called?

Answer 4

• Meiospores
  
  • ​The haploid spres prodvuce via meiosis
• Th zygote before meiosis is the only stage that is diploid

Question 5

Zygomycetes

Answer 5

• Division Zygomycota
• ​algal-like fungi, zygote fungi, conjugation fungi
  
  • Bread mold fungi
• found in freashwayer and marine envionments
  *

Question 6

How do the mycelium in Zygomycetes reproduce asexually?

Answer 6

• Generate many haploid spores (sporangiospores).
• The sporangiospores germinate with a hupha emergin from each sprore

Question 7

What is a zygosporangium?

Answer 7

• It is the product of two mating strains (+) and (-) fusing their gametangia.
• A youn zygosporangium has 2 tpyes of haploid nuclei.
• There is a resting phase between Plasmogamy (fusion of gametangia) and Karygamy (nuclei asctually fuse)

Question 8

Ascomycetes

Answer 8

• Division Ascomycota
• Sac fungi
• Found in terrestrial, freshwater, and marine
• Either unicellular (yeast) or uninucleate with septas

Question 9

What are the gametangia on Ascomycetes?

Answer 9

• Ascogonia (+)
• Antheridia (-)
• The nuclei of the antheridia always goes to the ascogonia after plasmogamy

Question 10

How many nuclei form at the end of meiosis and mitosis of the Ascomycetes?

Answer 10

• Karyogamy occurs in the ascus
• Diploid nucleus undergoes meiosis with 4 haploid nuclei
• Then those nuclei undergo mitosis = 8 nuclei
• Those nuclei become ascospores and are sent off by wind!

Question 11

What is the hymenium?

Answer 11

• Layer of cells that contain sprore producing cells of the ascomycetes and basidiomycetes

Question 12

Basidiomycetes

Answer 12

• Division Baidiomycota
• ​Club fungi
• Mushrooms or toadstools

Question 13

Structure of a Basidiocarp

Answer 13

• Pileus - cap or a mushroom
• Stipe - stalk
• Annulus - ring like band around the stipe
• Gills (lamellae)
  
  • ​terminal dikaryotic cells form club shaped basidia
  • This is where meiosis takes place

Question 14

Why can molds not be placed into a Division of Fungi?

Answer 14

• Their sexual phase is unknown
• Fungi Imperfecti or Deuteromycetes

Question 15

What is a yeast and what are some examples?

Answer 15

• Unicellular fungi that inhabits moist or aquatic habitats
• Live as commensals or parasites
• Reproduce asexually by budding
• Ex: saccharomyces cerevisiae - brewer’s yeast
• Yeast is used to make bread, win, cheese, and beer
• Candida - vagina disease
• Rhodotorula - pink shit on your shower

Question 16

What is a lichen? what are the three types?

Answer 16

• Composite organism
  
  • ​consisting of a fungus (mycobiont) and an alga (phycobiont) that are mutually dependent on each other
• Reproduce asexually by fragmentation and structures called soredia
• Crustose - flattened, crust like
• Foliose - leafy looking
• Fruticose - small branchin cylinders creating a bushy look