1. Protozoans
Animal-like Protists

2. Protozoans Includes forams and radiolarians
Found on surface and in bottom sediments
Unicellular
Animal like
Kingdom Protista
Subdivided into 3 phyla:
Ciliophora
Zoomastigina
Sarcodina

3. Ciliophora Largest group
Most free swimming, some attached to substrate
Move by beating microscopic cilia
Fresh and salt water

4. Sarcodina Forams, radiolarians, and amoebas
Live on surface of substrates
Move and eat using pseudopods
“amoeboid movement”

5. Zoomastigina Animal like protists Move using a flagella
Live in freshwater, saltwater, and as parasites within other organisms

6. Life Functions of Protozoans
All life functions carried out within 1 cell!
Ingestion – getting food in
Digestion – breaking food down
Respiration – food to energy (ATP)
Transport – gas exchange
Water balance/excretion
Sensitivity – responding to stimuli
reproduction

7. Vorticella Ciliophora Unicellular Ciliated protozoan
Sessile – attached to substrate

8. Ingestion and Digestion
Vorticella
Food is swept toward “mouth” oral groove by moving its ring of cilia
Food particles enter food vacuoles, where they are broken down.
Intracellular digestion – inside a cell

9. Respiration Converting food (sugars) into energy (ATP) using oxygen
Occurs in the mitochondria
Oxygen + Glucose -> Water + Carbon Dioxide +36 ATP
Vorticella uses ATP to contract its stalk

10. Transport Oxygen and Carbon Dioxide diffuse across the cell membrane
Oxygen diffuses IN
Carbon Dioxide diffuses OUT
Inside the cell food vacuoles move around and distribute nutrients

11. Water Balance and Secretion
Water moves into aquatic organisms like Vorticella through osmosis
Eventually they would burst, but…
Excess water is pumped out through the Contractile Vacuole
Excretory Vacuole – pumps out liquid waste
Helps maintain homeostasis (a stable internal environment)

12. Sensitivity Ability of an organism to respond to environmental stimuli
Vorticella
Responds to touch by contracting its stalk into a coil
Avoidance reaction to stimuli that may be harmful
Also contracts spontaneously

13. Reproduction Asexual reproduction
Binary fission – division of prokaryotic cell into 2 identical cells

14. Sexual reproduction Conjugation
2 parent protozoans exchange parts of their micronuclei when they come in contact (exchange genetic material)
Increases genetic variation
Binary fission then occurs, but with unique offspring.