BIOL 1202 Chapter : Protists
Document Summary
Concept 28. 1: most eukaryotes are single-celled organisms: protists are more diverse than all other eukaryotes, no longer considered a single kingdom, mostly unicellular, but some colonial and multicellular forms. Protists are nutritionally diverse: photoautotrophs contain chloroplasts, photosynthesize, heterotrophs absorb organic molecules or ingest larger particles, mixotrophs combine photosynthesis and heterotrophic nutrition. Endosymbiosis in eukaryotic evolution: much protest diversity has its origin in endosymbiosis, plastid-bearing lineage evolved into red & green algae, both underwent secondary endosymbiosis. Motility in protists: flagellates: move by 1 or more flagellae (9:2 microtubule ratio, ciliates: move by coordinated movement of cilia, amoebae: move by means of pseudopodia. Ciliate sexual reproduction: conjugation and reproduction. Protist (eukaryotic) diversity: protistans are a paraphyletic group, 5 supergroups , excavata, chromalveolata, rhizaria, archaeplastida, unikonta, figure 28. 3. Concept 28:2 excavates include protists with modified mitochondria and protists with unique flagella: main feature of euglenozoans is a spiral or crystalline rod of unknown function inside their flagella.
