Chapter 25 - endosymbiosis + types of eukaryotes

endosymbiosis

a symbiotic relationship in which 1 organism lives inside the body or cell of another

endosymbiotic theory

eukaryotes are a combination of organisms—mitochondria+ chlorplasts began by living in other cells

figure 25.3: endosymbiosis process

1. started with an ancestral prokaryote

2. plasma membrane folds in within itself

3. developed into cell w/ nucleus + endomembrane system

4. engulfed anaerobic bacterium+new host cell

5. engulfed photosynthetic bacterium

serial endosymbiosis

mitochondria evolved before chloroplasts in the sequence of endosymbiosis

evidence for endosymbiosis

both replicate by slipping, have ribosomes, + enzymes + transport to membranes of bacteria

primary endosymbiosis

the first time a prokaryote was taken by a eukaryote to be part of its cell

secondary symbiosis

where a heterotrophic eukaryotic cell engulfs a photosynthetic eukaryote cell

multicellular colonies

first multicellular forms, collection of connected cells

simple colonies

an intermediate for single-cell eukaryotes + multicellular forms, may take shape when dividing cells are held together by proteins that connect together

how multicellularity evolved

gradually evolved from single-cell organisms, started with cells clustering(like colonies), each group gained a specialized function + then distinct tissues + organs were made.

simple multicellularity

composed of simpler cells w/ little specialization

complex multicellualrity

highly differentiated cell types organized into tissues/organs with a complex communication system

three domains of life

bacteria, archaea, eukarya

super groups of eukaryotes

excavates, euglenzoans, SAR, archaeplastids

excavates

has unique cytoskeleton features, feeding groove on 1 side of body

euglenozoans

flagellated protists, very diverse, ex: predatory heterotrophs, photosynthetic autotrophs

SAR

stramenopiles, alveotes, rhizarians

stramenopiles

came from secondary endosymbiosis

alveotes

membrane enclosed sacs(ex alveoli)

rhizarian

diverse supergroup of unicellular eukaryoes (amoebas)

archaeplastids

a monophyletic group w/ green/red algae + land plants, the ancestor was engulfed by cyanobacteria