Download Protists - cloudfront.net

Protists
Ch. 29
“The bridge between bacteria and animals.”
What are Protists?
- First eukaryotes
- make up the Kingdom Protista
- unifying characteristic: “eukaryote that is not a plant,
animal, or fungus”
- “Junk Drawer group”
- 7 paraphyletic phylums
Where did they come from?
A Prokaryote
● lost cell wall
● membrane infolded to
form nucleus and
Endoplasmic reticulum
● became a Eukaryote
Then Eukaryote
● gained mitochondria and
chloroplast by engulfing other
bacteria
○ Endosymbiosis: ‘living together
in close association’
○ mitochondria = aerobic bacteria
○ chloroplast = cyanobacteria
Protista
Topic for the Day
By the end of class you will be able to:
-identify and the features used to group
Protists.
-explain how Protists are the bridge to
multicellularity.
Defining Protists
Characteristics used to group
1. Cell Surface
2. Locomotion
3. Food sources (Metabolism)
4. Reproduction strategy
Cell Surfaces
Some protists have:
All protists have:
- plasma membrane - extracellular matrix
- form cell walls
- Cysts (similar to endospores)
- allow cell to go dormant
- survive some harsh
environments
Plasma Membrane
ECM
Question:
“Which cell surface does ALL protists have?”
Locomotion
- flagella
- whip-like extension that rotates to move
- cilia
- short hair-like projections that wave back and forth
- pseudopodia
- extensions of the plasma membrane
- filopodia
- axopodia
Flagella and Cilia
Pseudopodia “False Feet”
Filopodia
Axopodia
Question:
“Which type of locomotion uses hundreds of
little hairlike projections to help the cell swim?”
Food Source (Metabolism)
Phototroph
- use photosynthesis to produce food
Phagotroph
- do phagocytosis; bring food particles into their body
Osmotroph
- ingest food that has been liquified
Mixotroph
- both phototrophic and heterotrophic
Phototrophs
Phagotroph
Osmotroph
Mixotrophs
Euglena
Question:
“In which type of nutritional strategy does the
cell bring the food into its body using
phagocytosis?”
Reproduction Strategy
Asexual
- Cell division (Mitosis)
- one cell splits into two
- Budding
- a smaller individual buds off the original
- Schizogony
- one cell splits into 3 or more
Reproductive Strategy
Sexual
- Meiosis
- forming of sex cells (egg and sperm)
- later fertilize each other
Cell Division
Budding
Schizogony
Meiosis
Question:
“Which type of reproduction strategy involves
the formation of multiple nuclei and results in 3
or more cells being produced?”