Kingdom Protista - Chapter 12.3

•       The kingdom protista is composed of microscopic and macroscopic organisms of various types. 
•       They are classified together mostly because they do not fit into other kingdoms rather than because they are similar or closely related. 
•       They are less diverse than bacteria or archaea, but are more diverse than any other eukaryotic kingdom.

A few main characteristics:           

•       Most are microscopic
•       Can be autotrophs or heterotrophs, most are aerobic
•       Most are single celled like bacteria and archaea however, they are eukaryotes like plants animals and fungi

Protists are classified into three main groups:

• Protozoa: animal-like protists (heterotrophic)
• Can obtain their food as scavengers, as predators (engulfing bacteria through endocytosis), or as parasites living in larger organisms
• Most are unicellular and motile
• They live in aquatic environments, wet soil and in fluids
• Algae: plant-like protists (autotrophic – photosynthesize)
• There is a lot of variation in this group! – algae include all aquatic eukaryotes that carry out photosynthesis
• Can range in size from single cells to large seaweeds (kelp)
• Slime Moulds and Water Moulds:  fungus-like protists (heterotrophic)
• These slimy little guys are especially difficult to classify
• Produce spores like fungi, move and ingest food like animals, and have cellulose cell walls like plants.

Read pages 432-449, see page 433 for overview of the protists