Lecture 3 | Eukaryotes

Question 1

What is the size of a Eukaryotic cell?

Answer 1

about 10-100 micrometers

Question 2

What are the key derived traits of a Eukaryotic cell?

Answer 2

Nucleus
Membrane-bound organelles
Well-developed cytoskeleton

Question 3

What is a cytoskeleton and its function?

Answer 3

Network of fibers within the cell
Provides support
Allows for asymmetry (have different shapes on different sides)
Changing shape

like the poles for holding up the tent

Question 4

What is endosymbiosis?

Answer 4

Relationship between 2 species in which 1 lives inside the other

Question 5

What is Serial Endosymbiosis?

Answer 5

A series of endosymbiotic events occuring within the history of a lineage of cells

(having multiple endosymbiotic events occurring in sequencing)

Question 6

What is Primary Endosymbiosis (1st Degree)?

Answer 6

Phagocytosis of bacterium (prokaryote) by larger cell (prokaryote or eukayote)

when prokaryote gets eaten

Question 7

What are two examples of primary endosymbiosis?

Answer 7

Mitochondria
Chloroplasts

Question 8

What is Secondary Endosymbiosis?

Answer 8

Bigger eukaryote (heterotrophic) engulfs a smaller eukaryote (autotrophic)

the smaller eukaryote becomes a 2nd degree plastid

Question 9

What is a plastid?

Answer 9

General term for chloroplasts and related organelles

all organelles are plastids, not all organelles are plastids

Question 10

What is the Plastid Evolution?

Answer 10

Chloroplasts derived from cyanobacteria (prokaryote) via 1st degree endosymbiosis
2nd degree plastids derived from red or green algae (eukaryotes) via 2nd degree endosymbiosis

Question 11

What is the basic process of serial endosymbiosis?

Answer 11

Heterotrophic euk (w/ mitochondria) engulfs cyanobacteria → results in green algae (autotrophic euk w/ chloroplasts)
Heterotrophic euk engulfs green algae → results in autotrophic euk w/ 2nd degree plastids

Question 12

What makes Eukaryotes diverse?

Answer 12

Mostly unicellular
Many colonial or multicellular
Complex cellular organization

Question 13

What are the nutritional strategies of Eukaryotes?

Answer 13

Photoautotrophs
Heterotrophs
Mixotrophs: capable of photosynthesis and heterotrophy

Question 14

Is the evolution of eukaryotes set and stone?

Answer 14

No. New data = rapidly changing hypothesis

Question 15

How are Eukaryotes classified?

Answer 15

Supergroups - we are responsible for 5

Question 16

What eukaryotes do supergroups categorize?

Answer 16

Mostly unicellular (not exclusively)
Protists, plants, fungi, animals

Question 17

How are the super groups named?

Answer 17

After morphological features of some of the members

Question 18

How are supergoups defined?

Answer 18

Based on molecular evidence (DNA sequences)

Question 19

What are the Ancestral Eukaryotic Traits?

Answer 19

Nucleus, membrane-bound organelles
Aerobic respiration
Mitochondria from 1st degree endosymbiosis
Cytoskeleton

Question 20

How did Eukaryotes acquire their shared traits?

Answer 20

Derived from Domain Eukarya, now are Ancestral Traits

all Eukaryotes have these traits

Question 21

What are the 5 supergroups?

Answer 21

Archaeplastida
SAR
Amoebozoans
Opisthokonta
Discoba

Question 22

What are the types of eukaryotes in the Archaeplastida group?

Answer 22

Red algae, green algae, land plants - all photosynthetic

Question 23

What are Archaeplastida and their shared derived trait?

Answer 23

Ancient-Plastids
Chloroplasts via 1st degree endosymbiosis

Question 24

How do Archaeplastida contribute to evolution?

Answer 24

Partcipated in 2nd degree endosymbiosis
Got eaten, became secondary plastids

Question 25

What is Red Algae?

Answer 25

Red due to phycoerythrin Primarily multicellular, often highly branched Absorbs blue and green light Live very deep (abt 30m down) is warm, tropical water

Question 26

What is Green Algae?

Answer 26

Closely related to land plants - very similar to chloroplasts Many forms (unicellular, colonial)

Question 27

What are the 2 main groups of Green Algae?

Answer 27

Chlorphytes (freshwater) Charophytes (sister group to plants)

Question 28

What is the shared derived trait for the SAR supergroup?

Answer 28

2nd degree endosymbiosis of red algae

Question 29

What are the 3 major clades for the SAR supergroup?

Answer 29

Stramenophiles, alveolates, rhizarians

Question 30

What are Amoebozoans and their shared derived trait?

Answer 30

Typical "blob" shape Shared derived trait: lobe or tub shaped psuedopodia (false feet)

Question 31

What are 2 examples of Amoebozoans?

Answer 31

Slime molds - not fungi Entamoebas - free-living or parasitic

Question 32

What is the Opisthokonta supergroup?

Answer 32

Diverse group Includes animals, fungi, sevral groups of protists

Question 33

What are Nucleariids?

Answer 33

Subgroup of the Opisthokonta supergroup Protists, closely related to fungi

Question 34

What are Choanoflagellates?

Answer 34

Subgroup to the Opisthokonta supergroup Unicellular, closely related to animals

Question 35

What is the Discoba supergroup and their shared derived trait?

Answer 35

Extremely Diverse Shared Derived Traits: Crystalline rod in flagella Some have 2nd degree plastids via green algae( mixotrophic)

Question 36

What are 2 examples of Discoba?

Answer 36

Trypanomosomes - often pathogenic Euglenids - often mixotrophs