Unicellular Eukaryotes Flashcards
Environment
Require moisture
Protista
Grouping of unicellular eukaryotes
Protozoa
Animal-like unicellular eukaryotes
Protophyta
Plant-like unicellular eukaryotes
Disadvantages
- Size is limited
- Short life span
- No division of labour
Advantages
- Rapid reproduction
- Minimal resources required
Locomotion: Methods
- Flagella
- Cilia
- Pseudopodia
Undulipodia
- Flagella + cilia
- 9 pairs of microtubules arranged around a central pair
Flagella
Propel water to the flagellum axis
Cilia
Propel water to the cell surface
Pseudopodia
- Temporary cytoplasmic protrusions extended
- Used for movement and phagocytosis
Taxonomy
Classificied by body type
* Flagellates
* Ciliates
* Amoebas
Flagellates
One or more flagella to propel cell
Ciliates
Numerous cilia covering cell membrane
Amoebas
- Irregular shape
- Travel using pseudopodia
- PM can be covered with a ‘test’
- ‘test’ from sand grains, Ca, or Si
Nutrition/Digestion
Heterotroph or autotroph
Holozoic feeding
Ingest visible particles of food (phagocytosis)
Saprozoic feeding
Ingest food in a soluble form
Cytosome
- Cell mouth
- Site of phagocytosis
- Most ciliates, Many Flagellate
- Amoebas don’t have (phagocytosis occurs anywhere)
Cytoproct
- Site where undigestible matter is expelled
- Many ciliates
Reproduction
- Sexual by conjugation
- Asexual by binary fission
- Requires 2 hosts: Intermediate & definitive
Intermediate host
- Asexual stage
- Vertebrae in plasmodium
Definitive host
- Sexual Stage
- Insect in plasmodium
3 stages of life
- Sporozoite: spore-like stage
- Merozoite: intermediate stage
- Trophozoite: Adult stage
Macronuclei
- Metabolism, synthesis, development
- Cannot survive without
- Divide mitotically
Micronuclei
- Sexual reproduction
- Cannot reproduce without
- Divide amitotically
Conjugation
- 2 paramecium’s make contact
- Micronuclei divide by meiosis and macronuclei degenerate
- 3 / 4 micronuclei degenerate
- Remaining micronuclei divides to form male & female pronuclei
- Male pronuclei exchanged
- Male & female pronuclei fuse