1. Protists

2. Protists
The Unicellular Eukaryotes

3. General Characteristics
• First appeared 1.5 billion years ago
• First eukaryotic organism
• Eukaryotes
• Mostly unicellular
• Mostly aerobic
• Most are motile

4. • Classified together because they do not fit
into other kingdoms, rather than because
they are similar or closely related to one
another
• Most diverse group of eukaryotes

5. Helpful Protists
• Major producers and make up the bulk of
the lowest consumer level in aquatic
ecosystems.
• Used in commodities
– Ex. Seaweed is in sushi, toothpaste and
paints.

6. Harmful Protists
• Many are parasites
• Can cause serious disease
– Ex. Malaria and giardiases

7. The Origin of Eukaryotes
• Membrane bound nucleus
– Through the infolding of the cell membrane in and
ancestral prokaryote in order to increase surface area

8. The Origin of Eukaryotes
• Mitochondria
– Through endosymbiosis of an ancestral prokaryote

9. The Origin of Eukaryotes
• Chloroplast
– Through endosymbiosis of an ancestral photosynthetic
prokaryote

10. Terms:
• Endosymbiosis = a single-celled
organisms living inside another organism
• Endocytosis = engulfing of particles
through the extention of a cell membrane

11. Examples of some groups:
Amoeba
Nucleus
Video:http://www.youtube.com/watch?
Pseudopodia:
v=W6rnhiMxtKU extensions of the
cytoplasm

12. Amoeba
Key Features
• Create pseudopods (extentions of cytoplasm)
• Unicellular
Locomotion
• Pseudopods extend and contract
Feeding
• Feed through endocytosis
• Some are human pathogens (parasites)
Ex. amoebic dysentery is cause by an Entamoeba (causes
intestinal bleeding)

13. Flagellates

14. Key Feature
Flagellates
• Possess one or more flagella (long whip-like structures)
• Unicellular
Locomotion
Flagella
Feeding
Some feed on other protists
Some are human pathogens (parasites)
Ex. Trypanosoma gambiensis in the tse tse fly causes
human sleeping sickness.
http://www.youtube.com/watch?v=4aVUrGO97Zg

15. Sporozoans

16. Sporozoans
Key Feature
• Produce spores
• Unicellular
Locomotion
Non-motile
Feeding
Parasitic (obtain nutrients from the bodies of their hosts)
Ex. Plasmodium cause malaria.

17. Sporozoans
When red blood
cells bursts
toxins are
released
causing chills
and fever
Some types of
malaria can be
fatal
Very serious
world-wide
disease
http://www.youtube.com/watch?v=RqRuSwZey_U&feature=related

18. Slime moulds

19. Slime moulds
Key Feature
• Their life cycles have unicellular stages and
multicellular stages
Locomotion
• Flagella or pseudopods
Feeding
- Heterotrophs
http://www.youtube.com/watch?v=q6rqyaYYZeo&feature=related

20. Red Algae

21. Life Cycles
• Unicellular protists:
– Asexual - Binary fission
– Sexual – Conjugation

22. Life Cycles
• Multicellular protists:
– Sexual reproduction
– Formation of haploid spores (through meiosis)
which can fuse to produce a diploid zygote