8.4 Evolution of Eukaryotes

Question 1

Eukaryote

Cells with _________ with ______

Answer 1

nuclei enveloped by a nuclear membrane

nuclear pores.

Question 2

Eukaryote

Cells with ____

Answer 2

mitochondria

Question 3

Eukaryote

Cells with _____ called ______ and ______

Answer 3

cytoskeleton components
actin filament
microtubules

Question 4

Eukaryote

Cells with ___ and ____ though some extant eukaryotes do not have _____ and _____ but have descended from _____ and _____ ancestors.

Answer 4

flagella and cilia

Question 5

Eukaryote

Presence of ____ that consist of DNA.

Answer 5

chromosomes

Question 6

Eukaryote
Cells undergo cell division,
____.

Answer 6

mitosis

Question 7

Endosymbiosis
• endo =
• sym =
• biosis =

Answer 7

inside
together
living

Question 8

Endosymbiotic Theory
– _______(1960s)
– Eukaryotic organelles were _____
– Eukaryotic cells originated from ______ which evolved to be _____ from each other.
– _____ and _____

Answer 8

Lynn Margulis
prokaryotic cells
engulfing another cell
dependent
mitochondria, plastid

Question 9

Endosymbiotic theory

Mitochondria&chloroplasts
–
–

Answer 9

internal parasite
ingested but not digested

Question 10

Endosymbiotic theory

Benefits: source of molecules for ______

Answer 10

biochemical activities (e.g., ATP, organic molecules)

Question 11

Endosymbiotic Theory

Evidence/support
– Modeofreproduction:
– W/own ____ and _____
– Surroundingmembranes:____,____

Answer 11

splitting
circularDNA , ribosomes
inner, out

Question 12

Modern-daysymbiosis:______ and _____

Answer 12

Cyanophora paradoxa
cyanobacteria

Question 13

Nucleus First Evolution
• ____ was lost in primitive anaerobic bacteria
• Flexibility of the _____ led to the in-folding formation
– ____ and ____

Answer 13

Cell-wall
plasma membrane
nucleus, ER

Question 14

______ Endosymbiosis
• givesrise to all
metabolic processes
of plastid in protists
– Primary
– Secondary

Answer 14

plastid

Question 15

Transition Organism
• Unicellular organism with “_____” as endosymbionts

Answer 15

cyanelles

Question 16

Symbiogenesis
• Evidences
1.
2.
3.

Answer 16

Membrane
DNA
Reproduction

Question 17

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)

Answer 17

cellular respiration
photosynthesis

Question 18

Why did the researchers choose one plant mitochondria and five bacterial species in the comparison matrix?

Answer 18

They wanted to identify which bacterium is most closely related to the ancestor of mitochondria.

Question 19

Which bacteria has an rRNA gene that is most similar to that of wheat mitochondrion?

Answer 19

tumefaciens is most similar to the wheat mitochondrial rRNA gene.

Question 20

What is the significance of this similarity?

Answer 20

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.