Protists Flashcards
Are protists monophyletic or paraphyletic?
Paraphyletic
What is the difference between Eukaryotes and Prokaryotes and what are protists classified under?
Protists are eukaryotes and have compartmentalization of nucleus and organelles (membrane bound organelles)
How did organelles form in protists?
Prokaryotic cell membrane folded in on itself which caused formation of endoplasmic reticulum (which happened due to a mutation)
What is endosymbiosis and which organelles were effected by this?
- Engulfing of other organelles
- Mitochondria and Chloroplasts were engulfed because they were originally individual cells
When brown algae engulfed red algae, which already had chloroplasts, what is this called?
Secondary endosymbiosis
Are protists unicellular or multicellular and which is more beneficial?
- Protists are both
- Multicellularity is more beneficial
What are the three taxa in the supergroup Excavata?
Diplomonads, parabasalids, and euglenozoans
Describe Diplomonads?
- Unicellular
- Move with flagella
- Have 2 nuclei
- Have degenerate mitochondria (ancestors had mitochondria and now it doesn’t function correctly/may not have one at all)
- Giardia: most common intestinal parasite in the U.S.
Describe Parabasalids?
- Live in termite guts
- Undulating membrane for locomotion
- Use flagella
- Lack mitochondria which is a derived trait
Describe Euglenozoa?
- Earliest eukaryotes to possess mitochondria
- Some have chloroplasts but may become heterotrophic in dark
- Others strictly heterotrophic (may be parasitic)
- Asexual reproduction only
- Contractile vacuoles: collect excess water
- African Sleeping Sickness
What taxa are in supergroup Chromalveolata?
- Dinoflagellates
- Apicomplexans
- Ciliates
- Brown Algae
- Oomcyetes
Describe Dinoflagellates?
- Photosynthetic and unicellular
- Move with flagella
- Live in aquatic environments
- Some are bioluminescent
- “Red tides” are blooms: can cause deaths
Describe Apicomplexans?
- Spore forming animal parasites
- Plasmodium causes malaria
- Toxoplasma gondii: causes reckless behavior
- Causes infections in humans with immunosuppression
Describe Ciliates?
- Feature large number of cilia arranged in longitudinal rows or spirals around the cell
- Pellicle: tough but flexible outer covering
- 2 types of nuclei: Micronucleus (without will reproduce asexually) and Macronucleus (essential for function)
- 2 types of vacuoles: Food vacuoles (digestion of food) and Contractile vacuoles (regulation of water balance)
Describe Brown Algae?
- Not plants
- Diatoms: unicellular, unique double shells made of silica
- Conspicuous seaweed
Describe Oomcyetes?
- Caused potato famine
- Can be aquatic or terrestrial
- Pathogens (make things sick) or saprobes (feed on dead things)
What taxa is in supergroup Opisthokonta?
-Choanoflagellida
Describe choanoflagellida?
- Most like common ancestors of animals
- Single flagella, surrounded by funnel shaped collar (structure matched in sponges)
- Use collar to feed on bacteria
Is Amoebozoa a taxa or supergroup?
Both
Describe Amoebozoa?
- Move by pseudopods
- Slime molds (not related to fungi): single celled, multinucleate, oozing masses and single cells combine
- Causes amoebic dysentary
What taxa are in supergroup Rhizaria?
- Foraminifera
- Radiolara
- Cercozoa
Describe Foraminifera?
- Pore studded shells called tests, through which thin podia emerge (podia used for swimming and eating)
- Produce limestone with tests
Describe Radiolara?
- Produce intricate mineral skeletons
- Needle like pseudopods
Describe Cercozoa?
- Mostly heterotrophic
- Abundant in soil and in all freshwater and marine habitats
- Many have filapodia
- May be most abundance predator but have no mouth
What taxa is in the supergroup Archaeplastida?
Rhodophyta
Describe Rhodophyta?
- Red algae range in size
- Have accessory photosynthetic pigments other than chlorophyll
- Red
What are the two monophyletic groups that make up Green Algae?
- Chlorophyta
- Charophyta (most closely related to plants)
Describe Chlorophytes?
- Many lines of specialization derived from chlorophytes
- Cell specialization in colonial chlorophytes
- Haploidiplontic live cycles in multicellular chorophytes
What is haploidiplontic?
There are stages of life that are haploid and stages that are diploid. All plants are haploidiplontic. The gametophyte generation makes the sex cells.
Describe the haploidiplontic life cycle.
-Starts with multicellular diploid stage (sporophyte)
This produces haploid spores by meiosis
The diploid spore mother cells (sporocytes) undergo meiosis in sporangia
This makes four haploid spores and these are the first cells of the gametophyte generation
-Then the multicellular haploid stage (gametophyte)
Spores divide by mitosis
This produce gametes through mitosis
Gametes fuse to form diploid zygote
What is the difference between Charophytes and Chlorophytes? Which came first and where do land plants fall in this order?
- Charophytes have phylogenetic relationship to land plants
- Chlorophytes came first, then charophytes, then land plants
