EVOLUTION OF EUKARYOTIC CELLS Movie
Origin of the nucleus and
endoplasmic reticulum. Fig 20.1
Endosymbiosis. Fig 20.2
-
Mitochondria
-
Chloroplasts
Evolution of mitosis and
sexual reproduction
asexual
reproduction. Fig 20.3
self-fertilization
cross-fertilization. Image
Image2
Eukaryotic organisms have:
- a
true nucleus
-
membrane-enclosed organelles
-
"9+2" flagella and cilia. Most have flagella or cilia. Fig. 5.21a.
image Movie!
- Unicellular,
colonial,
multicellular
Kingdom Protista is artificial grouping. Fig 20.7 Table 20.1
- Classification does not represent evolutionary
relationships
Amoebas. Fig 20.8
pseudopodia
Forams. Fig 20.9
Radiolarians. Fig 20.10
Flagellates
- parasitic ex: Trypanosoma (African Sleeping Sickness)
- choanoflagellates are likely ancestors of all animals
Ciliates
- use cilia for movement and food capture. Fig. 20.12
Cellular slime molds
Plasmodial (acellular) slime
molds
Water molds
The endosymbiotic model
suggests chloroplasts originated at least three separate times from different
prokaryotic endosymbionts.
Dinoflagellates. Fig 20.14
-
both autotrophs (photosynthetic) and heterotrophs (parasites and predators)
- Most with cellulose and silica plates
- Many mutualistic with corals
- algal blooms and red tides.
Euglenoids. Fig 20.16
Diatoms
- Diatoms are mostly unicellular organisms with overlapping glasslike walls of silica.
- diatomaceous earth: White Cliffs of Dover
Green algae (single-celled). Fig. 20.19
- Chlorophyll a, chlorophyll b
- In same taxonomic category as the multi-celled green algae below
Green
algae (multicellular). Fig 20.20
- Similarities in chloroplasts & DNA and RNA sequence analysis indicate that green algae are the ancestors of all plants
- have similar cell division to higher plants - cell plate formation. Image
- Many seaweeds (including kelp and Sargassum)
- cultivated for food
Sporozoans
Plasmodium causes malaria. Fig 20.22
200 million people per year get infected in Africa alone; at least 2 million die per year
