Download Bio200- Lab lecture 8

Bio200- Lab lecture 8
THE PROTISTS
-
Unicellular eukaryotic organisms.
All types of habitats
Autotrophs or heterotrophs
Free-living or parasitic
Solitary or in colonies
I-Protozoa:
Animal-like protists
Heterotrophic
Very diverse: habitat
Feeding mode
4 groups: Flagellates, Amebas, Ciliates, Apicomplexans.
1-Flagellates: (zoomastigina)
Flagella
e.g. Trypanosoma
Parasitic flagellate causing African Sleeping Sickness.
Moves by means of a flagellum and an undulating membrane.
2-Amebas:
No defined shape
No permanent locomotory structures.
Pseudopods for movement (ameboid movement) and feeding.
3-Ciliates:
Move by means of cilia.
e.g. Pramecium
Free living F.W ciliate.
Macronucleus: controls everyday activities
Micronuclei: reproduction
4-Apicomplexans: (Sporozoans)
All parasitic
Resistant spore stage in the life cycle
Move by cellular flexing
e.g. Plasmodium
Parasite causing malaria; infects the RBC of vertebrates.
II-Algae:
- Plant-like photosynthetic protists
- Includes microscopic unicellular forms and giant muticellular
forms.
- Aquatic
- 5 groups: euglenoids, dinoflagellates, diatoms, green algae,
seaweeds.
1-Euglenoids:
e.g. Euglena
Flagellated
Both animal and plant characteristics.
2-Dinoflagellates:
e.g. Ceratium
Mainly marine, with few F.W. species.
2 flagella located in grooves in the cell wall.
Cell wall made of interlocking cellulose plates.
Cause the red tide phenomenon when it reproduces in
tremendous numbers.
3-Diatoms:
- Variety of cell shapes and patterns in the cell wall.
- Glassy cell wall, made of 2 halves.
- Accumulated cell wall of diatom fossils form the
diatomaceous earth (used as abrasive).
4-Green algae:
e.g. Clamydomonas
Unicellular.
e.g. Volvox
Spherical colonies
4-Seaweeds: Multicellular marine algae
Resemble plants, but lack stems, leaves and roots.
Multicellular green algae:
e.g. Ulva (sea lettuce)
Brown algae:
Brown or olive
e.g Kelp or Laminaria
Red algae:
Soft bodied, but some are encrusted with calcareous material. It
contributes to coral reefs formation.
III-Fungus-Like protists
Water molds
Thread-like hyphae
e.g. Saprolegnia