Protistans

1
Protistans

• Starr/Taggarts
• Biology
• The Unity and Diversity of Life, 9e
• Chapter 23

2
Key Concepts

• The kingdom Protista includes single-celled
  eukaryotic cells
• Fungu- like protistans include some parasitic
  organisms that are decomposers
• Animal-like protistans include nonphotosynthetic
  flagellated protozoans, sporozoans, and ciliates

3
Key Concepts

• Many plant-like protistans are photosynthetic
  flagellates and are important members of
  phytoplankton
• Some protistans are multicelled forms that
  include the red, brown, and green algae

4
Parasitic and Predatory Molds

• Resemble fungi
• Chytrids
• Water molds
• Slime molds

5
The Animal - Like Protistans

• Protozoans - Groups
• Sarcodina
• Amoebas
• Mastigophora
• Flagellates
• Apicomplexa
• Sporozoans
• Ciliophora
• Ciliates

6
A Sampling of Ciliated Protozoans

• Ciliated protozoans
• Paramecium
• Free-living and motile
• Cilia
• Contractile vacuole

7
Ciliated Protozoans

• Reproduction
• Sexually or asexually
• Conjugation

8
Ameoboid Protozoans

• Sarcodina
• Amoebas
• Foraminiferans
• Heliozoans
• Radiolarians
• Movement
• Pseudopods

9
Animal-like Flagellates

• Mastigophora
• Parasites or free living predators
• Flagellated protozoans
• Giardia lamblia
• Trichomonas vaginalis
• Trypanosomes
• African Sleeping Sickness
• Chagas disease

10
Representative Sporozoans

• Sporozoan
• Life cycle complex
• Involve 2 hosts or more
• Plasmodium
• Malaria
• Cryptosporidium
• Diarrhea
• Toxoplasma
• Birth defects

11
Life Cycle of Plasmodium - Malaria

• Infected mosquito bites human
• Sporozoites enter bloodstream and move to liver
• Sprozoites produce merozoites

12
Life Cycle of Plasmodium - Malaria
Some merozoites develop into gametocytes
13
Life Cycle of Plasmodium - Malaria
Another mosquito sucks up gametocytes which
develop into sporozoites in her salivary gland
14
A Sampling of the Single - Celled Algae

• Algae
• Euglenoids
• Euglena
• Chrysophytes
• Diatoms
• Silica shells
• Golden algae
• Yellow-green algae

• Dinoflagellates
• Marine
• Heterotrophs
• Red tides
• Toxin
• Mollusks and fish
• Massive die-offs
• Raw sewage and fertilizer

15
Euglenoids
16
Red Algae - Rhodophyta

• Red, green, purple or nearly black
• Accessory pigments, mainly phycobilins
• Most abundant in tropics
• Commercial products
• Agar
• Carrageenan
• Nori

17
Brown Algae- Phaeophyta

• Olive-green, golden, or dark brown
• Carotenoids and chlorophylls a, c1 , and c2
• Giant kelps are largest, most complex protistans

18
Green Algae - Chlorophyta

• Most similar to plants
• Chlorophylls a and b
• Largest number of species ( gt 7,000)
• Diverse
• Chlamydomonas - single-celled, freshwater
• Volvox - colonial, freshwater
• Ulva - marine sea lettuce

19
In Conclusion

• Protistans are eukaryotes
• Many are heterotrophs which include the water
  molds, chytrids, slime molds, and protozoans
• The fungus-like protists are decomposers or
  parasites
• Animal-like protozoans are internal parasites or
  live freely in aquatic habitats

20
In Conclusion

• Sporozoans have complex life cycles involving
  multiple hosts
• Single-celled and multiple-celled algae are
  photoautotrophs
• The red, brown and green algae are multicelled
  photosynthesizers
• The protistans are the simplest of the eukaryotes
• developed by M. Roig