Protists are an artificial group of eukaryotes that are neither animals, fungi, nor plants. They represent the vast diversity of eukaryotic organisms, and thus span the breadth of possibilities with regard to life history traits. They can be heterotrophs or autotrophs, unicellular to massively multicellular (though rarely with any specialized tissue organization), and can be found across ecosystems worldwide. Photosynthesis within protists is the result of multiple separate endosymbiotic events.
- 5.1: Introduction to Protists
- Protists are extremely diverse in terms of their biological and ecological characteristics, partly because they are an artificial assemblage of phylogenetically unrelated groups. Protists display highly varied cell structures, several types of reproductive strategies, virtually every possible type of nutrition, and varied habitats. Most single-celled protists are motile, but these organisms use diverse structures for transportation.
- 5.2: Heterotrophic "Protists"
- Heterotrophic organisms must consume organic matter to obtain energy. Under the umbrella of protists, there are several heterotrophic groups. This chapter will introduce slime molds and oomycetes, as these are groups commonly discussed in botany courses. However, it is important to note that there is a vast diversity of heterotrophic protist lineages not covered here with important and fascinating ecological roles.
- 5.3: Photosynthetic "Protists"
- Photosynthetic protists have derived their chloroplasts from multiple endosymbiotic events. Dinoflagellates, brown algae, and diatoms derived their chloroplasts from the secondary endosymbiosis of a red alga. Red algae, green algae, and plants derived their chloroplasts from the primary endosymbiosis of a cyanobacterium.
- 5.4: Chapter Summary
- A brief summary of the chapter concepts.