[IB Biology at GHS: Cell Biology]
Protists

The photo above shows several Paramecium: a typical protist cell

Kingdom Protoctista

Examples: Paramecium, Amoebas, Volvox

The photo at right shows a shape-shifting Amoeba: a typical protist cell

Characteristics:

* Mainly one-celled (unicellular) or exist as cell colonies

* Eukaryotic cells

* Possess a nucleus

* Have membrane-bound organelles

* All protist cells are unspecialized (they perform the life functions of multicelled organisms even though they are unicellular),

* Some are autotrophs (These possess a cell wall, chloroplasts and theycarry out photosynthesis.)

* Many are heterotrophs (These lack cell walls & chloroplasts, but carry out cellular respiration - use sugar as their energy source for their mitochondria.)

* Some are parasitic or may cause disease ( Giardia, African Sleeping Sickness, Amoebic dysentary).

Slichter