I. Origins of Eukaryotic Diversity

A. Review: What are the differences between prokaryotes and eukaryotes b?

-characteristics of three domains

1. What trends in prokaryotes suggest an evolutionary path to eukaryotes?

-multicellular forms

-prokaryotic communities: myxobacteria

-primitive compartmentation

B. Theory of Endosymbiosis (Margulis and Mereschkovsky)

1. A Model for the Origins of Eukaryotes

2. How are the three domains of life related?

3. Tentative Phylogeny of Eukaryotes 

Plants

Animals

Fungi

Protista

Autotroph and Heterotroph

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II. Representative Phyla: Protista

A. Parabasala and Diplomonadida

1. General characteristics

2. Trichmonas vaginalis

3. Trichonympha agilis

4. Giardia lamblia (Diplomonad)

B. Ciliophora

1. General characteristics

• cilia
• Ciliate Genetics: two types of nuclei b
• feeding behavior of Paramecium
• contractile vacuole: why does it need one?

III. Representative Phyla: Animalia

A. What is an animal?

1. Distinguishing characteristics:

• multicellular, heterotrophic
• collagen: structural proteins for body form  and cell junctions (e.g. desmosomes)
• presence of nervous and muscle tissue
• characteristic embyo development process controlled by Hox genes
• "morphing" embryo comparison

2. Hypothetical ancestry from colonial protist

B. Cnidaria

1. General characteristics

• radial symmetry
• gastrovascular cavity
• two body types: polyp and medusa
• cnidocytes
• simple nervous and muscle systems
• Hydra

C. Platyhelminthes

1. General characteristics

• bilateral symmetry
• gastrovascular cavity
• flame cells for osmoregulation
• nervous system
• How complex is the planarian nervous system?
• cilia for movement
• two heads!