Lecture 20 - Fungi (part 2) & Protists Flashcards

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1
Q

How are fungi key decomposers within the environment?

A
  • they’re saprotrophs
    • Break down wood, leaf litter, organic matter is soil
    • Really any carbon-containing substrate -> even jet fuel!
    • Provides inorganic nutrients essential for plant growth
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2
Q

Saprotrophs

A

ex: fungi

- sporotrophic fungi that get their nutrition from dead plant material & other non-living organic material

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3
Q

Endophytic

A
  • fungi that associates with plants
  • a fungus that lives inside a leaf or other plant part without causing harm to the plant
  • a reason fungi can be mutualists
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4
Q

Symbiotic

A
  • an ecological relationship b/t organisms of 2 different species that live together in direct & intimate contact
  • we see this in LICHENS
    • Symbiotic relationships between an ascomycete (or sometimes a basidiomycete or glomeromycete) fungus and a green alga and/or cyanobacterium
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5
Q

soredia

A
  • in lichens, a small cluster of fungal hyphae with embedded algae
  • how fungi reproduces asexually
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6
Q

Mixotrophs

A

• Mixotrophs, both photosynthetic and heterotrophic
• Have arisen independently in protist lineages
- we see this in protists

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7
Q

plastid

A
  • organelle that does cool things, either photosynthesis or cellular respiration etc. within the cell
  • are found in cells of photosynthetic eukaryotes
  • we see this in secondary endosymbiosis (photosynthetic eukaryote becomes the new plastid)
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8
Q

nucleomorphs

A
Residual nuclei (nucleomorphs) are strongest evidence of EST b/c some organisms usually in Rhizaria & the cryptonomads retain these multiple nuclei even though they have their own nucleus themselves
• Rhizaria and cryptonomads
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9
Q

pseudopodia

A
  • a cellular extension of amoeboid cells used in moving & feeding
  • we see this in the supergroup rhizarians
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10
Q

Phytoplankton

A

small planktonic things that photosynthesize
• Main cause of shellfish poisoning due to the toxins they produce
• Can result in huge “blooms”

  • we see this in the diatoms (in the subgroup Stramenopiles)
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11
Q

accessory pigment

A

another pigment other than the main photosynthetic pigment

  • usually help in either antioxidant properties or allowing the absorption of additional wavelengths of light
  • so it’s an accessory pigment, it’s not the primary pigment
  • we see this Brown Algae (in the subgroup Stramenopiles)
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12
Q

Holdfasts

A

anchorage

- a specialized structure in brown algae

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13
Q

Stipe

A

“stem”

- a specialized structure in brown algae

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14
Q

Blades

A

“leaves”

- a specialized structure in brown algae

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15
Q

analogous structures

A
  • the specialized structures in the brown algae (ex: holdfasts, stipe, blades) that AROSE independently from similar features in plants
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16
Q

zooplankton

A
  • UNICELLULAR organisms (zooplankton) that MOVE via cilia
  • they have to HUNT & EAT stuff in order to get their ENERGY, they don’t photosynthesize
  • most are PREDATORS that feed on bacteria & algae
  • we see this IN CILIATES (in the subgroup alveolates)
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17
Q

tests

A

the porous shell of a foram
• Name Foraminiferans (Forams) means “little hole” for their porous shells (tests)
• Made of calcium carbonate

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18
Q

Chlorophytes

A

mostly freshwater and terrestrial species
• Can be unicellular, multicellular and/or colonial
- we see this in Green Algae (supergroup Archaeplastida)

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19
Q

colonial

A
  • a colony of single-cell organisms is known as colonial organisms
  • we see this in Green Algae (supergroup Archaeplastida) specifically in chlorophytes
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20
Q

Charophytes

A

closely related to land plants

- we see this in Green Algae (supergroup Archaeplastida)

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21
Q

plasmodium (syn. syncytium)

A

• Form a mass called plasmodium (syn. syncytium), a single-celled cytoplasm containing many nuclei

  • the parasitic organism that causes malaria
  • we see this in plasmodial slime moulds (within the slime moulds (Mycetozoans) within the clade amoebozoans & in Apicomplexans!
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22
Q

sporozoites

A

specialized cells that INVADE host cells

  • ex: Plasmodium, parasite that causes malaria
  • we see this in Apicomplexans (within the subgroup Alveolates)
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23
Q

micronucleus

A

exchange of genetic material during conjugation

- we see this in the Ciliates (within the subgroup alveolates)

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24
Q

macronucleus

A
transcriptional active (produces RNA)
- we see this in the Ciliates (within the subgroup alveolates)
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25
Q

Describe how Fungi can be mutualists

A

Endophytic fungi associate with plants
• Not limited to roots (compared to mycorrhizae), found in all plant tissues
• Most are ascomycetes
• Provide a range of beneficial effects including producing anti-herbivory
toxins, increasing heat/drought/heavy metal tolerance

Animal mutualists
• Some occur in the guts of animals (chytrids in sheep)
• Ant colonies farming fungi for nutrients (Leaf cutter ants)

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26
Q

Describe Lichens

A
  • SYMBIOTIC relationships between an ascomycete (or sometimes a basidiomycete or glomeromycete) fungus and a green alga and/or cyanobacterium
  • GROW ON various SUBSTRATA: rocks, soil, trees, metal, concrete, plant leaves
  • Most are TERRESTRIAL but some are AQUATIC
  • ~13,000 species of lichens identified to date
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27
Q

What are the 3 growth forms of Lichens?

A
  1. fruticose (shrublike)
  2. foliose (leaflike)
  3. crustose (encrusting)
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28
Q

How do Lichens reproduce?

A
  • sexual via fungal life cycle

* asexual via soredia, fragmentation, other specialised structures

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29
Q

Describe Eukaryotes

A

• Eukaryotes: protists, plants, animals, fungi

• Have membrane-BOUND organelles
• Have a NUCLEUS
• Have a CYTOSKELETON for support (Allows for asymmetrical cell forms)
- most are SINGLE-CELLED organisms

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30
Q

What does cytoskeleton that is for support in Eukaryotes allow for?

A

Allows for asymmetrical cell forms

31
Q

Protists are the most abundant eukaryotic

lineages and are…

A

unicellular

32
Q

Some protists can exist in…

A

colonies or be multicellular

33
Q

What are the diverse nutritional modes of protists?

A
  • Photoautotrophs, containing chloroplasts
  • Heterotrophs
  • Mixotrophs, both photosynthetic and heterotrophic (Have arisen independently in protist lineages)
34
Q

What are the diverse reproductive cycles of protists?

A
  1. Asexual
  2. Sexually
  3. Alternating between 2N and N
35
Q

How many supergroups are within Eukarya? AND how many unresolved protistan groups?

A
  • 4 supergroups within Eukarya

* 2 unresolved protistan groups

36
Q

What is endosymbiosis?

A

is a symbiotic relationship where one thing lives inside another

37
Q

What did Mitochondria and Chloroplasts used to be?

A
  • Mitochondria used to be a HETEROTROPHIC, O2 using prokaryote
    • All derived from a common ancestor
  • Chloroplasts used to be a PHOTOSYNTHETIC prokaryote
    • Arose multiple times
38
Q

Describe Primary endosymbiosis

A

engulfing of a photosynthetic cyanobacterium by a heterotrophic eukaryote

39
Q

When did the first transfer of photosynthesis from a prokaryote to a eukaryote occur?

A

in primary endosymbiosis

40
Q

Describe Secondary endosymbiosis

A

a heterotrophic eukaryote ate a photosynthetic eukaryote
• Usually a red or green algae
• Spread photosynthesis to 3 out of 4 supergroups
• Photosynthetic eukaryote becomes the new plastid

41
Q

What is the Supergroup Excavata? What are the 3 monophyletic clades?

A

• Excavates have an “excavated” feeding groove, based on cytoskeletal morphology

  • 3 monophyletic clades:
  • Diplomonads
  • Parabasalids
  • Euglenozoans
42
Q

Describe the features of Diplomands

A

Mitochondria: Mitosomes (lack functional ETC)

Metabolism: Anaerobic pathways

Nutritional Mode: Parasites (ex. Giardia intestinalis, “Beaver fever”)

Nuclei: 2 equal sized

Flagella: Multiple

Other features: *

43
Q

Describe the features of Parabasalids

A

Mitochondria: Reduced, called hydrogenosomes

Metabolism: Anaerobic, releasing H as byproduct

Nutritional Mode: Parasite (ex. Trichomonas vaginalis, STI)

Nuclei: *

Flagella: 2

Other features: Undulating membranes

44
Q

Describe the features of Euglenozoans

A

Mitochondria: Single, large (Kinetoplastids)

Metabolism: *

Nutritional Mode: Predatory heterotrophs, autotrophs, mixotrophs, parasites

Nuclei: *

Flagella: Crystalline rod inside one of their flagella

Other features: Light detectors (Euglenids)

45
Q

What is the Supergroup SAR? What are the 3 monophyletic clades?

A
  • Very large group defined by DNA similarities
  • 3 monophyletic clades:
    1. Stramenopiles
    2. Alveolates
    3. Rhizarians
46
Q

Describe the diagnostic features of the Supergroup Stramenopiles

A

2 Flagella: 1 with numerous hairlike projections, 1 smooth

47
Q

Describe the diagnostic features of the Supergroup Alveolates

A

Membrane-bound sacs (Alveoli) under the plasma membrane

48
Q

Describe the diagnostic features of the Supergroup Rhizarians

A

Amoebas and flagellated protists with pseudopodia

49
Q

Describe the Diatoms

A
  • within the supergroup SAR: subgroups Stramenopiles
  • Unicellular algae with a silica covering made of two pieces
  • ~10,000 species
  • Phytoplankton
  • Main cause of shellfish poisoning due to the toxins they produce
  • Can result in huge “blooms”
50
Q

Describe the Brown Algae

A
  • within the supergroup SAR: subgroups Stramenopiles
  • Multicellular, mostly marine “seaweeds’
  • Alternation of generations life cycle
  • Brown due to carotenoids (accessory pigment) in their plastids
  • Have specialised structures such as
  • Holdfasts – anchorage
  • Stipe – “stem”
  • Blades – “leaves”
  • Above arose independently from similar features in plants -> analogous structures
51
Q

What is included in the supergroup SAR: subgroups Stramenopiles?

A
  • diatoms
  • brown algae
  • golden algae & oomycetes
52
Q

What is included in the supergroup SAR: subgroup alveolates?

A
  • dinoflagellates
  • apicomplexans
  • ciliates
53
Q

Describe the Dinoflagellates

A
  • within the supergroup SAR: subgroup alveolates
  • Cells are reinforced by CELLULOSE PLATES
  • Contains 2 flagella within grooves (they SPIN when they move)
  • Photoautotrophic (through secondary endosymbiosis), mixotrophic and heterotrophic aquatic organisms
  • Causes “RED TIDE”, blooms in the ocean
  • Can produce TOXINS
54
Q

Describe the Apicomplexans

A
  • within the supergroup SAR: subgroup alveolates
  • Unicellular parasites of animals
  • Contains sporozoites, specialised cells that invade host cells
  • Ex. Plasmodium, parasite that causes malaria
  • Have complex life cycles with asexual and sexual stages and which require 1-2 hosts
55
Q

Describe the Ciliates

A
  • within the supergroup SAR: subgroup alveolates
  • Unicellular organisms (ZOOPLANKTON) that move via cilia
  • Most are PREDATORS that feed on bacteria and algae

• Have 2 nuclei:

- Micronucleus
- Macronucleus

• Reproduce via binary fission

56
Q

What are AND describe the 2 nuclei in the Ciliates

A
  • Have 2 nuclei:
  • Micronucleus -> exchange of genetic material during conjugation
  • Macronucleus -> transcriptional active (produces RNA)
57
Q

How do Ciliates reproduce?

A

Reproduce via binary fission

58
Q

What is included in the supergroup SAR: subgroup rhizarians?

A
  • radiolarians
  • foraminiferans (forams)
  • cercozoans
59
Q

Describe the Radiolarians

A
  • within the supergroup SAR: subgroup Rhizarians
  • Have delicate, SYMMETRICAL internal silica skeletons
  • Pseuodpodia RADIATE from central body
  • Mostly marine
60
Q

Describe the Foraminiferans (Forams)

A
  • within the supergroup SAR: subgroup Rhizarians
  • Name means “little hole” for their porous shells (TESTS)
  • Made of calcium carbonate
  • PSEUDOPODIA extend through the pores for moving, feeding, and building the shell
  • Aquatic, both marine and freshwater
  • 90% of all forams are known FROM FOSSILS
61
Q

Describe the Cercozoans

A
  • within the supergroup SAR: subgroup Rhizarians
  • Amoeboid and flagellated protists
  • Common in marine, freshwater and soil ecosystems
  • Heterotrophs (most) and parasites (many) and predators
62
Q

What is unique about the Supergroup Archaeplastida? AND what is included?

A

• Composed of red algae, green algae and land plants

  • Monophyletic clade
  • common ancestor is an ancient protist that engulfed a cyanobacterium
63
Q

Describe Red Algae

A
  • within the Supergroup Archaeplastida
  • ~600 species, red due to accessory pigment PHYCOERYTHRIN
  • ABSORBS blue and green light
  • Most ABUNDANT large algae in tropical marine habitats
  • Multicellular, still considered “seaweeds”
  • Commonly EATEN as a food source (Nori in sushi)
64
Q

Describe Green Algae

A
  • within the Supergroup Archaeplastida
  • ~7000+ species
  • Single-celled and multicellular
  • Green due to CHLOROPHYLL in their chloroplasts
  • Paraphyletic group:
    • Chlorophytes
    • Charophytes
65
Q

Describe the paraphyletic group within the Green Algae

A

• Chlorophytes -> mostly freshwater and terrestrial species
- Can be unicellular, multicellular and/or colonial

• Charophytes -> closely related to land plants

66
Q

Describe the Supergroup Unikonts AND the 2 major clades

A
  • Includes animals, fungi, and some protists
  • Two major clades:
    • Amoebozoans
    • Opisthokonts
67
Q

What is each clade within the Supergroup Unikonts supported by?

A

molecular systematics and analysis of myosin proteins

  • However, we don’t know the root of the Eukaryotic tree at the Unikonts
  • We don’t know which group of Eukaryotes came first
68
Q

Describe the Supergroup Unikonts: Clade Amoebozoans AND what is included

A

• Includes amoebas with lobe or tube-shaped pseudopods

  • slime moulds (Mycetozoans)
  • tubulinids
  • entamoebas
69
Q

Describe the Slime Moulds (Mycetozoans, formerly Myxomycota)

A
  • within the supergroup Unikonts: clade Amoebozoans
  • Produce fruiting bodies that aid in spore dispersal
    • But no longer considered fungi -> convergent evolution

• Occur in two forms:

  1. Plasmodial slime moulds
  2. Cellular slime moulds
70
Q

Describe the Plasmodial slime moulds form

A
  • Form a mass called plasmodium (syn. syncytium), a singlecelled cytoplasm containing many nuclei
  • Produced via mitosis that does NOT end in cytokinesis
  • Extends pseudopodia through substrate to feed (phagocytosis)
  • When environment dries, stops expanding and produces sporangia
71
Q

Describe the Cellular slime moulds form

A

Feeding stage consists of solitary cells but join together when food is depleted, forming aggregated amoebas that produce stalked sporangia for spore dispersal

72
Q

Describe the Tubulinids

A
  • within the supergroup Unikonts: clade Amoebozoans
  • Unicellular protists found in soil and aquatic environments
  • Most are heterotrophs, eating bacteria and other protists
  • Ex Amoeba proteus
  • Free-living
73
Q

Describe the Entamoebas

A
  • within the supergroup Unikonts: clade Amoebozoans
  • Parasites, infecting vertebrates
  • Ex. Entamoeba histolytica causes amoebic dysentery, which is spread by contaminated water
74
Q

What are the 2 major groups of protists that remain uncertain AND why?

A
  • So hard to isolate and culture, grouping them based on morphology and/or DNA is near impossible
  • Haptophytes
  • Cryptomonads