Terms: Symbiosis, mutualism, parasitism, commensalism, myxotrophic, coencytic 1. What is a eukaryote in terms of how genetic information (DNA) is stored and cellular structures, especially those using filaments and tubules? 2. What evidence is there that mitochondria and chloroplasts have an endosymbiotic origin? 3. Look at the Eukaryote phylogeny in the text. Back in the day, you would have been taught that there were five kingdoms; Animals, (land) Plants, Fungi, Monera (Archaea and Eubacteria) and Protists – the single celled Eukaryotes. What kind of phylogenetic group would Protists be?

Mitochondria and chloroplasts are believed to have developed from symbiotic bacteria, specifically alpha-proteobacteria and cyanobacteria respectively

Mitochondria and chloroplasts likely evolved from engulfed prokaryotes that once lived as independent organisms; at some point, a eukaryotic cell engulfed an aerobic prokaryote, which then formed an endosymbiotic relationship with the host eukaryote, gradually developing into a mitochondrion

Mixotrophic

Mixotrophic protists are single celled eukaryotes that can obtain carbon and energy from more than one trophic process (e.g. photosynthesis and phagocytosis)

The ability of protists to combine photosynthetic and heterotrophic nutrition in a single cell is well known