8.4 Evolution of Eukaryotes Flashcards
Eukaryote
Cells with _________ with ______
nuclei enveloped by a nuclear membrane
nuclear pores.
Eukaryote
Cells with ____
mitochondria
Eukaryote
Cells with _____ called ______ and ______
cytoskeleton components
actin filament
microtubules
Eukaryote
Cells with ___ and ____ though some extant eukaryotes do not have _____ and _____ but have descended from _____ and _____ ancestors.
flagella and cilia
Eukaryote
Presence of ____ that consist of DNA.
chromosomes
Eukaryote
Cells undergo cell division,
____.
mitosis
Endosymbiosis
• endo =
• sym =
• biosis =
inside
together
living
Endosymbiotic Theory
– _______(1960s)
– Eukaryotic organelles were _____
– Eukaryotic cells originated from ______ which evolved to be _____ from each other.
– _____ and _____
Lynn Margulis
prokaryotic cells
engulfing another cell
dependent
mitochondria, plastid
Endosymbiotic theory
Mitochondria&chloroplasts
–
–
internal parasite
ingested but not digested
Endosymbiotic theory
Benefits: source of molecules for ______
biochemical activities (e.g., ATP, organic molecules)
Endosymbiotic Theory
Evidence/support
– Modeofreproduction:
– W/own ____ and _____
– Surroundingmembranes:____,____
splitting
circularDNA , ribosomes
inner, out
Modern-daysymbiosis:______ and _____
Cyanophora paradoxa
cyanobacteria
Nucleus First Evolution
• ____ was lost in primitive anaerobic bacteria
• Flexibility of the _____ led to the in-folding formation
– ____ and ____
Cell-wall
plasma membrane
nucleus, ER
______ Endosymbiosis
• givesrise to all
metabolic processes
of plastid in protists
– Primary
– Secondary
plastid
Transition Organism
• Unicellular organism with “_____” as endosymbionts
cyanelles
Symbiogenesis
• Evidences
1.
2.
3.
Membrane
DNA
Reproduction
Origin of Mitochondrion & Chloroplasts
(Endosymbiotic Theory)
3. Bacteria entered larger cells as parasites / undigested prey; they began to live inside the host where they performed either ______ (mitochondria) or ______ (chloroplasts)
cellular respiration
photosynthesis
Why did the researchers choose one plant mitochondria and five bacterial species in the comparison matrix?
They wanted to identify which bacterium is most closely related to the ancestor of mitochondria.
Which bacteria has an rRNA gene that is most similar to that of wheat mitochondrion?
tumefaciens is most similar to the wheat mitochondrial rRNA gene.
What is the significance of this similarity?
The significance of this similarity is that it supports the theory of endosymbiosis. This theory provides evidence that prokaryotic organisms during division or other environmental factors gave rise to the eukaryotic cells.
