I. Endosymbiosis A. Occurred in early eukaryotes Pelomyxa - lacks mitochondria
B. Mitochondria and chloroplasts are similar to bacteria 1. circular DNA 2. similar translational machinery - DNA, RNA, ribosomes
3. divide by process similar to binary fission 4. double membranes of mitochondria and chloroplasts - inner membrane part of prokaryote - outer membrane from cell membrane of “host”
II. Eukaryotic Reproduction A. Sexual 1. haploid gametes 2. advantage in evolutionary adaptation 3. more diversity 4. includes self-fertilization - offspring still not identical to parent
B. Asexual 1. no gametes 2. offspring genetically identical to parent 3. parthenogenesis - new organism from an unfertilized egg - many insects, lizards, fish, amphibians
III. Kingdom Protista A. Most diverse kingdom 1. most unicellular eukaryotes (except yeast) 2. all eukaryotes not plant, animal, or fungus 3. “catch-all” kingdom - some protists more closely related to plants, animals, or fungi than other protists
III. Kingdom Protista A. Most diverse kingdom (cont’d) 4. algae (many of the photosynthetic protists) 5. protozoa (single-celled heterotrophs) 6. molds (similar to fungi)
B. Diplomonads - 2 nuclei and multiple flagella - Giardia intestinalis
C. Euglenozoans 1. includes heterotrophs, photosynthetic autotrophs, and pathogenic parasites 2. Trypanosoma - sleeping sickness - tsetse flies 3. Euglena - many can alternate between photosynthetic and heterotrophic
D. Alveolates - have tiny membrane-enclosed sacs just under the cell membrane 1. dinoflagellates a. marine/aquatic phytoplankton (photosynthetics) b. some are heterotrophic c. some are bioluminescent d. toxic red tides (from overgrowth)
2. apicomplexans a. animal parasites b. form spores c. Plasmodium - malaria
3. ciliates - use cilia for locomotion - heterotrophs that dine on bacteria, algae, and other ciliates - paramecium
E. Stramenopiles - have a “hairy” flagellum 1. water molds a. freshwater organisms b. decompose dead plant and animal material c. includes downy mildews d. can be parasitic - fish - potato blight - downy mildew of grapes
2. diatoms a. unicellular, photosynthetic algae b. cell wall contains silica (found in many abrasives) c. marine/aquatic d. diatomaceous earth
3. brown algae a. largest and most complex algae (fast-growing) b. marine c. multicellular d. most seaweeds e. kelp
F. Amoebozoans use pseudopodia
F. Amoebozoans use pseudopodia 1. free-living amoebas - marine/aquatic - soil
2. parasitic amoebas - dysentery - Naegleria fowleri
3. plasmodial slime molds - oozing mass of slime - many nuclei - decomposers
4. cellular slime molds - can aggregate into slugs - change location - differentiates and sporulates
G. Red and green algae 1. closely related to plants 2. both contain chlorophyll 3. red algae are important reef species - hard cell walls, non-motile
G. Red and green algae (cont’d) 4. green algae - Chlamydomonas - Volvox - many sea weeds