Flashcards in Lecture 23 - Endosymbiosis + Eukaryotic Diversity (SI) Deck (26):
-hypothesis for origin of eukaryotes
3 proposals of serial endosymbiosis
1. ancestors of mitochondria = aerobic, heterotrophic prokaryotic endosymbionts (alpha)
2. ancestors of chloroplasts = photosynthetic prokaryotes (cyanobacteria)
3. ancestral host = archaean/proto-eukaryote (diverged from archaeal ancestors)
What are 5 pieces of evidence?
chloroplasts/mitochondria + bacteria have similar:
2. transcription tools
3. enzymes + transport systems
stealing + using chloroplasts from prey
-passed from generation to generation
What are 2 qualities of plastid evolution?
1. mitochondria arose through descent from bacterium engulfed by cell from archaeal lineage
2. photosynthetic cyanobacterium was engulfed by hetertrophic eukaryote
What did plastid bearing lineage evolve into?
-red and green algae
What is the evolutionary sequence of land plants?
2. green algae
3. land plants
how did mitochondria originate?
from engulfed, originally free-living proteobacteria
What catalyzed the 3 adaptive radiations?
eukaryotic organisms capable of existence as single cells
Protists often contain _____ at some point in their lifecyle
What are Euglena?
-single-celled mixotrophic protist
ingestive, animal like nutrition
photosynthetic plant like
What are the 3 ecological categories of protists?
What are eukaryotic flagella?
-extensions of cytoplasm with a support of 9 + 2 microtubule system
What are 4 parasites
1. plasmodium (maleria)
2. P. ramorum (sudden oak death)
3. P. shumayae (kills fish)
4. P. infestans (potato late blight)
What are cysts?
-resistant cells formed by protists
-can survive harsh conditions
communities of organisms that drift passively or swim weakly in the water
Size of microbial eukaryotes
-single celled (mostly, protists)
Diversity of microbial eukaryotes
tens of thousands of described species
2 types of microbial eukaryotic nutrition
1. Photosynthetic (microalgae)
2. Engulfment (protozoa)
3 types of microbial eukaryotic reproduction
1. binary fission (most common)
2. sexual reproduction/recombination
3. budding + multiple fission (least common)
Distribution of microbial eukaryotes
every biotic ecosystem on the planet