Protists Flashcards
What were Whittaker’s 5 kingdoms?
Animalia, Plantage, Fungi, Protista Monera
What are the protists?
Mostly unicellular eukaryotes which don’t fit into the plant, fungi or animal categories
What are the 3 types of protists?
Algae - Plant like, autotrophs
Protozoa - Animal like, heterotrophs
Slime molds - Fungus like, heterotrophs
Why are the protists important?
The first organisms observed through a microscope, are the proposed origin of multicellularity and arose approximately 2 billion years before the rest of the eukaryote groups.
Describe cyanobacteria
- Previously thought of as ‘Blue-green algae’ however now known to be more closely related to bacteria
- Can inhabit extreme conditions as large strings of cells
- Lived in microbial mats producing stromatolites
What are the 2 proposed theories for the origin of the eukaryotes?
- Autogenous theory - arose gradually through steps
- Endosymbiosis theory - larger anaerobic prokaryote engulfs a smaller prokaryote, physiological processes of endosymbiont adopted (evidence provided by similarities of photosynthetic structures of cyanobacteria and protists as well as the molecular analysis of base sequences)
How are the protozoa classified and what are their 4 categories?
According to their method of locomotion. - Flagellates (use flagella) - Amoebae - Sprorozoans (no locomotion) - Ciliates (use cilia) NOTE: Groups are not phylogenetically correct but convenient
Why do slime moulds resemble fungi?
No phylogenetic relationship - convergent evolution
What are the 2 groups of slime moulds?
- Plasmodial slime moulds (diplontic)
- Cellular slime moulds (haplontic without a true plasmodium)
Describe plasmodial slime moulds
Heterotrophic feeding stage exists as an amoeboid mass called a plasmodium, a multinucleate mass of protoplasm, which has no cell walls.
