Midterm2- General protistology Flashcards
Morphology and movement
What are the 3 themes?
- Protists are both organisms and individual cells, they solve their problems through structure and behavior 2. Protist biology breaks textbook rules 3. Importance of protists in ecosystems/human health
Morphology and movement
Morphological types of protists
4
Flagalletes/ciliates/ameoba/cocci
Morphology and movement
What is the difference between EUKARYOTIC flagella and cilia?
They are the exact same thing (not in bacteria tho)
Morphology and movement
Definition: Flagalletes
Protists with 1 or more Flagella
Morphology and movement
Definiton: Ciliates
Protists with MANY short flagella
Morphology and movement
Definition: Amoebas
Protists with variable, dynamic cell shapes due to temporary cell protrusions “psudopods”
Morphology and movement
Definition: Cocci
Protists with no Flagella and a fixed spherical or ellipsoidal cell shape
Morphology and movement
What does the cytoskelaton do?
4 things
Gives structure/shape to the cell, supports flagella/psudopodia, intracellular trafficking and mitotic spindle/cell division
Morphology and movement
What component of the cytoskelaton is involved in MiTOtic spindle?
Microtubules
MTOC
Morphology and movement
What component of the cytoskelaton is involved in cell division
Microfillaments- contractile ring
Morphology and movement
Microtubules features
Monomers- Alpha and Beta tubulin –> protofilament –> microtubules (13 pfs) POLAR = negative and positive (beta) end
Morphology and movement
Microfillaments features
Actin –> Microfilaments, 1 type makes tightly bound rope, polar
not hollow
Morphology and movement
What cytoskelaton component is most common in Ameobas?
Microfillaments
Morphology and movement
What cytoskelaton component is most common in Flagalletes?
Microtubules (9 + 2)
Morphology and movement
What is an Axoneme? What is its arrangement
The microtubular structure inside flagellum, 9 + 2
Morphology and movement
What does 9 + 2 mean
9 pairs of Mts on the outside and 2 Mts on the inside, 1 complete pair (13 pt) and 1 incomplete (11)
Arrangement of Mts inside flagella (axenome)
Morphology and movement
What is the Basal body/Kinetosome and what is its arrangement?
Microtubular structure at the BASE of the flagella, 9 + 0 type
Morphology and movement
What is 9 + 0
9 triplets with nothing in the centre, 1 complete 2 not
Morphology and movement
Cortical microtubular structures
(Flagellar roots)
Anchored to more Mts and other structures
Morphology and movement
3 components of flagella
Axenome, basal body, cortical microtubular structures/flagellar roots
9 + 2, 9 + 0
Morphology and movement
Opisthokonts
Flagella
RARE single flagella to generate propulsion
Morphology and movement
What is the MTOC
Microtubule Organizing Centres: MTs emerge, assemble and are regulated here
Morphology and movement
What is a Karyomastigont?
Flagella close to nucleus, Mitotic spindle (Mt) interacts with nucleus, basal body/MTOC arranges spindles
Morphology and movement
What is the main function of Mastigonemes?
Stremenopiles have 1
To reverse the water flow, flagella then pull instead of push
Morphology and movement
What is Cirri
Used in Euplotes
Bundles of cilia that are used like legs to walk on a substrate, have a specific gait
Used in Euplotes
Morphology and movement
What is the undulating membrane?
trypnanosoma brucei in blood
Best for swimming in viscous fluids, moves like a sail/flag
Trypanosoma Brucei in blood
Morphology and movement
What is phototaxis and who uses it?
Moving towards the light, euglena has specific organelle
Morphology and movement
Kirbyana
Excavata; parabasalia
Have intracellular axenomes
Morphology and movement
What is the difference between Mts and Mfs
Mfs are thinner and not hollow, both have polarity. Mfs are best for contractillity and cell movement
(constriction ring during cell division)
Morphology and movement
Lobopodia
Types of psudopods
Broad tube like psudopodia - supported by actin (Mfs)
Morphology and movement
Filipodia
Types of psudopods
Very thin protrusions supported by actin (Mfs)
Morphology and movement
Reticulopodia
Types of psudopods
Fused psudopodia that form elaborate networks supported by tubulin (Mts)
Morphology and movement
Axopodia
Types of psudopods
Straight, long and on bending psudeopodia supported by tubulin (Mts)
Morphology and movement
What are key features of actin/microfilaments?
Contractility and polymerization
Morphology and movement
What is the endoplasm?
Amoeboid locomotion
Contains oragnelles, liquid & moves results in extensions of psudopods and uroid
INNER
Morphology and movement
What is ectoplasm?
Ameoboid locomotion
Gel like and rigid
OUTER
Morphology and movement
What 2 forces causes the flow of cytoplasm in ameobas?
Ameoboid locomotion
Polarity: In endoplasm mfs are aligned in a BUNDLE Contractility: In ectoplasm mfs arranged in a MESH that sqeeze cytoplasm from one end to another
bundle/mesh
Morphology and movement
What 2 groups do not have flagella?
True fungi and Red algae
Skelatons and Buoyancy
Endo/Exo skelaton definition
Endo: Inside or below the plasma membrane Exo: Outside the plasma membrane (sometimes called wall)
Skelatons and Buoyancy
Cyto/Skelaton definitions
Cytoskelaton: precise term, conserved feature of ALL eukaryotes (mfs and mts) specific roles Skelaton: Everything that is NOT a cytoskelaton that supports cell, more vague and variable
Morphology and movement
What is the most likely form of the LCA?
Flagallete- most dominant form across the tree and only 2 groups have lost this feature
Red algae, fungi
Skelatons and Buoyancy
Organic skelaton
Composition based classification
Made up of organic molecules- proteins/polysaccharides synthesized by the cell
Skelatons and Buoyancy
Calcareous Skelaton
Composition based classification
Made up of CaCO3
Calcium carbonate
Skelatons and Buoyancy
Siliceous Skelaton
Composition based classification
Made up of mostly SiO2
Silica
Skelatons and Buoyancy
Aggluntinated Skelaton
Composition based classification
Made up of foreign particles collected from the environment
Skelatons and Buoyancy
What is the plant cell wall
An organic (made up of cellulose) exo (outside plasma membrane) skelaton
Skelatons and Buoyancy
Microsporidia
Cysts and spores
Have a thick multilayer wall rich in CHITIN used to survive environmental stresses
Most examples are parasitic- live partly in environment/ partly in host
Skelatons and Buoyancy
Resting environmental stages
Cysts and spores
Ciliates use complex resting environmental stages with organic walls in harsh conditions
Skelatons and Buoyancy
What type of skleaton do Dinoflagalletes have?
Organic ENDO- cellulose plates assemble in alveoli under plasma membrane
Theca
Skelatons and Buoyancy
What type of skelaton do Diatoms have?
Siliceous EXO- 2 overlapping valves outside the membrane
Frustrule
Skelatons and Buoyancy
What type of skelaton do Coccolithophorids have?
Haptophytes
Calcareous EXO- Extracellular CaCo3 plates/scales
Coccoliths
Skelatons and Buoyancy
What type of skelaton do Foraminferans have?
Calcareous EXO with reticulopodia, planktonic and large
Skelatons and Buoyancy
What type of skelaton do radiolarians have?
Siliceous EXO- Common in water column
Skelatons and Buoyancy
Name 3 marine sediments caused by skelatons?
Pink beach in Japan: Red formineferans Star sand: foraminferans White Cliffs of Dover: Coccolithophorid
Skelatons and Buoyancy
How do these groups float?
Skelatons cytoplasm and organelles make them sink
HUGE Vacuoles: pumps out salt to make solution less dense than seawater
Cant do this in freshwater
Skelatons and Buoyancy
Why are radiolarians poorly studied??
2 reasons
- More common in open ocean 2. Hard to grow in a lab
Skelatons and Buoyancy
Where do Acantharians live in the ocean?
Radiolarians
Near the surface, have photosyntetic algae living inside so need sunlight
Skelatons and Buoyancy
Describe Acantharian spines
Radiolarians
10 pairs made up of Stronsium sulphate (SrSO4)
Skelatons and Buoyancy
What type of skelaton does Acantharians have?
Radiolarians
ENDO- stronsium sulphate dissolves in sea water organic EXO- cortex above membrane
Skelatons and Buoyancy
Describe Acantharian axopodia
Radiolarians
Mts or Mfs?
Supported by MTs, each has an MTOC, expands and contracts
Skelatons and Buoyancy
Describe Acantharians plasma membrane
Radiolarians
Surrounds cytoskelaton and skelaton
Endo skelaton
Skelatons and Buoyancy
Describe Acantharians periplasmic cortex and central capsule
Radiolarians
Endo or exo?
Organic (cellulose) exoskelaton with holes for spines/axopods to go through Central cortex is same but on inner side
Exo
Skelatons and Buoyancy
Describe Acantharians Endoplasm
Radiolarians
Multiple nuclei found here, symboitic algae, other organelles
Skelatons and Buoyancy
Describe Acantharians Ectoplasm
Radiolarians
Vacuoles are found here- where FEEDING happens, also threads and protrusions that expand and contract
feeding/movement
Skelatons and Buoyancy
Describe Acantharians Myonemes
Radiolarians
Mts or Mfs?
Contractile- made up of actin/Mfs, can raise plates over eachother
Purpose is to change volume/density or help food reach ectoplasm
Skelatons and Buoyancy
How do Acantharians capture prey?
Radiolarians
Axopodia (Mts) are sticky and retract to move prey, hits cortex then ectoplasm
Kinteocysts (inside axopodia) make them sticky and help capture prey
Skelatons and Buoyancy
Are radiolarians a monophyletic group?
Acantharians and Polycistenes
Most likely, polycistenes still have a small crystal of SrSO4
vestigual organ = sign of evolution
Protist morphology and movement
How did we know Parabasalians form a group before sequencing?
They all share a unique feature “Parabasal body”
Protist morphology and movement
What can we say about relatedness and morphology?
Big flashy external features are generally adaptive and don’t always say much about relatedness ex. Flagella/amoeba/cilia
Convergent evolution
Protist morphology and movement
What is the Parabasal body?
Parabasalians
Mf or mt?
Corresponds to Golgi, supported by thick cytoskelatal fibre (not mf or nt)
Protist morphology and movement
What is the flagellar structure of Trichanomas?
Parabasalian
3 points
4 flagella with 4 basal bodies, Parabasal fibres connect to Parabasal body, fourth flagella is sideways and forms undulating membrane- supported by COSTA
Protist morphology and movement
What is the Axostyle and Pelta
Trichanomas- Parabasalian
Mts or Mf
Forms a hood- made up of MTs
Entirely unique structure but made up of familiar components
Protist morphology and movement
What is the Karyomastignont?
Parabaslia
Nucleus, flagella, MTOC and other associated features (axostyle and pelta) are physically close to eachother
Replication happens in coordination
Protist morphology and movement
What is Deltotrichonympha?
Parabasalian
Has 1 nucleus and thousands of flagella, when it replicates it sheds all but 4 flagella. This is a derived feature of ancestor
