Lecture 3 Flashcards
Can a low power microscope reveal a great variety of organisms in a drop of pond water?
Yes
Define Protist
The informal name of the group of mostly unicellular eukaryotes.
What kind of a Cladistic group do protists constitute?
Polyphyletic
Protists are _____ and thus have organelles and more complex than prokaryotes.
Eukaryotes
Most protists are _____, but there are some colonial and multicellular species.
Unicellular
Which group of eukaryotes can be considered the most nutritionally diverse?
Protists
What does the diversity of nutrition in protists consist of?
Photoautotroph-Heterotroph-Mixotroph PHM
Define Mixtotroph
The combination of photosynthesis and heterotrophic nutrition.
In what ways can protists reproduce?
Some protists reproduce asexually, while others reproduce sexually, or by the sexual processes of meiosis and fertilization.
What are the 4 supergroups of eukaryotes?
Excavata-SAR-Archaeplastida-Unikonta ESAU
Explain everything important about Unikonta
Gymnamoebas are free living in many habitats and Entamoebas are parasites.
The Unikonta do not contain a shell, cilia, or flagella; instead has pseudopodia, extensions of cytoplasm shared by micro tubules and micro filaments.
Grows by cytoplasmic steaming; cytoplasm undergoes reversible phase change from solution to gel.
Used for locomotion, and to trap food particles which are then internalized by infolding of the cell membrane (phagocytosis).
It has food vacuoles (responsible for the ingestion of phagocytoses food) and contractile vacuoles (removal of water and wastes). It removes water and conserves solutes. Diffusion and osmosis and constantly changing cytoplasmic composition; organism must regulate.
What can be said about Slime Molds in the Unikonta Supergroup?
They were once thought to be fungi due to the production of fruiting bodies and spores. But, this is a case of convergent evolution and the different types of slime molds include Plasmodial and Cellular Slime Molds.
Explain everything important about the Excavata Supergroup
Characterized by a rod with spiral or crystalline structure inside each of their flagella. Two best studied groups are the kinetoplastdis and euglenids. EKE
What are some important things to note about the Kinetoplastids under the Excavata Supergroup?
Some are free-living and some are parasitic.
African Trypanosomiasis, Chagas’ Disease, and Leishmaniasis are all diseases that can be caused by these kinetoplastids.
What happens in the African Trypanosomiasis Disease?
Sleeping sickness; fatal if untreated, difficult to treat.
What happens in Chagas’ Disease?
It is American Trypanosomiasis; causes lingering illness and sometimes death.
What happens in Leishmaniasis?
It usually happens in the tropics, causes organ damage and nasty skin sores.
How are the diseases from Kinetoplastids transmitted?
They are ALL transmitted through insects that bite vertebrates (tsetse flies for sleeping sickness, reduviid bugs for Chagas, and sand flies for Leishmaniasis). TRS
Have there been any vaccines developed for trypanosome cause diseases? What happens upon infection?
No; the organisms rapidly change cell surface antigens, so it’s impossible to prevent infection. Once infected, this also challenges the hosts’ immune system.
How is treating trypanosome diseases?
It is difficult; antibiotics dont work and both host and parasite are eukaryotes, so anti-Protozoan drugs often have a harmful side effect.
Explain everything about Arcaheplastida
They’re the closest relative to land plants and developed from Cyanobacterial endosymbiosis.
What are the different types of endosymbiosis?
Primary and Secondary
What does SAR stand for? (What is included in it)
Stramenopiles-Alveolates-Rhizarians
Explain everything about Rhizarians
They move and feed with pseudopodia; there are bulging extensions form the cell and the cytoplasm streams to form these extensions.
