Endosymbiosis

Outline

Ways that members of "algal" phyla get their energy -- some are:

autotrophic

heterotrophic

mixotrophic

auxotrophic

Endosymbiosis and the origin of plastids

plastids arose from cyanobacteria through primary endosymbiosis

cyanobacteria vs. chloroplasts

The process of endosymbiosis and stages along the way:

  1. predator-prey

  2. lazy predator-cooperative prey

  3. host-temporary guest (transient endosymbiosis)

  4. host-endosymbiont (permanent endosymbiosis)

  5. cell-organelle

This process occurred at the root of the Archeoplastid supergroup

Viridiplantae

chlorophytes (green algae) and kingdom Plantae

chloroplast characteristics

Rhodophyta

red algae

chloroplast characteristics

Glaucophyta

eukaryotic algae with "cyanelles" instead of chloroplasts

cyanelle characteristics

an "incomplete" endosymbiosis

secondary endosymbiosis

the chromalveolate supergroup (alveolates and stramenopiles)

stramenopiles

  • phaeophytes -- brown algae

  • bacillariophytes -- diatoms

  • chrysophytes -- golden-brown algae

  • xanthophytes -- yellow-green algae

non-stramenopiles

cryptophytes

haptophytes

chloroplast characteristics

cryptophytes also have a nucleomorph and phycobilins

alveolates

apicomplexans

ciliates

dinoflagellates

characteristics of typical chloroplasts

dinoflagellates have a wide variety of chloroplasts that vary in pigments, number of membranes and arrangement of thylakoids

apparently they have lost and regained chloroplasts repeatedly

tertiary endosymbiosis?

Excavates

euglenophytes

chloroplast characteristics

apparently evolved from a green alga

Rhizaria

chlorarchniophytes

chloroplast characteristics

apparently evolved from a green alga

Vocabulary

click here to go to endosymbiosis vocabulary


on to the next topic -- red algae

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