Lecture 3- Eukaryotes

Question 1

True or False: Primary phagocytosis of a cyanobacterium led to the ancestor of today’s mitochondria

Answer 1

False; the primary phagocytosis of a cyanobacterium led to the ancestor of red and green algae

Question 2

What is a mixotroph?

Answer 2

Organism capable of autotrophy (photosynthesis) and heterotrophy

Question 3

________ is the process in which a eukaryote engulfs a living prokaryote like bacteria

Answer 3

Primary endosymbiosis

Question 4

What are plastids?

Answer 4

Membrane-bound organelles, like chloroplasts, that result from secondary endosymbiosis

Question 5

What is the pigment responsible for the color of red algae?

Answer 5

Phycoerythrin

Question 6

________ occurs when a eukaryote engulfs another eukaryote

Answer 6

Secondary endosymbiosis

Question 7

What shared derived trait(s) do all stramenopiles share?

Answer 7

Two flagella (one short/smooth and one long with hair-like projections)

Question 8

True or False: Possessing a mitochondria is a homologous characteristic for the eukarya

Answer 8

TRUE

Question 9

What shared derived trait(s) do all archaeplastida share?

Answer 9

Chloroplasts via primary endosymbiosis

Question 10

True or False: The eukaryotic tree is a polytomy

Answer 10

TRUE

Question 11

An organism is observed to have a protective shell made of calcium or silica. To which eukaryotic supergroup could this organism belong?

Answer 11

SAR

Question 12

Which eukaryotic supergroup is sister to the opisthokonta?

Answer 12

Amoebozoa

Question 13

What shared derived trait(s) do all alveolates share?

Answer 13

Alveoli

Question 14

In which eukaryotic supergroup are red and green algae found?

Answer 14

Archaeplastida

Question 15

What shared derived trait(s) do all opisthokonta share?

Answer 15

Genetic similarities

Question 16

What is the function of alveoli in alveolates?

Answer 16

Support plasma membrane

Question 17

True or False: Nucleariids are sister to fungi and choanoflagellates are sister to animals

Answer 17

TRUE

Question 18

Eukaryotic Cell Structure- List key derived traits

Answer 18

• Nucleus
• Membrane-bound organelles
• Well developed cytoskeleton: Network of fibers within cell- support, allows for asymmetry, changing shape

Question 19

Endosymbiosis

Answer 19

Relationship between 2 species in which 1 lives inside the other, common in evolutionary history (mitochondria, chloroplasts)

Question 20

Serial Endosymbiosis

Answer 20

Series of endosymbiotic events

Question 21

Primary Endosymbiosis

Answer 21

Phagocytosis of bacterium by larger cell

Question 22

Describe the first primary endosymbiosis

Answer 22

Mitochondria (first): Alpha proteobacteria (aerobic) within archaea (anaerobic)

Question 23

Describe later primary endosymbiosis

Answer 23

Chloroplasts (later): Cyanobacteria within heterotrophic eukaryote

Question 24

Secondary Endosymbiosis

Answer 24

Bigger eukaryote (heterotrophic) engulfs smaller eukaryote (autotrophic) -> secondary plastids

Question 25

Plastid

Answer 25

General term for chloroplasts and related organelles

Question 26

Chloroplasts were derived from cyanobacteria via ___________ endosymbiosis

Answer 26

Primary

Question 27

Secondary plastids were derived from red or green algae (eukaryotes) via ______________ endosymbiosis

Answer 27

Secondary

Question 28

Heterotrophic eukaryote with mitochondria engulfs cyanobacteria ->

Answer 28

Primary endosymbiosis, leads to green algae (autotrophic eukaryote with chloroplasts)

Question 29

Heterotrophic eukaryote engulfs green algae ->

Answer 29

Secondary endosymbiosis, leads to autotrophic eukaryote with secondary plastids

Question 30

Is eukaryotic evolution rapidly changing hypotheses?

Answer 30

Yes

Question 31

5 Eukaryotic Supergroups

Answer 31

Archaeplastida, SAR, Amoebozoa, Opisthokonta, Discoba

Question 32

What is included in the 5 eukaryotic supergroups?

Answer 32

Protists, plants, fungi, animals

Question 33

Protists (General)

Answer 33

"The very first" Represents the 1st eukaryotic cells, does not include plants, animals, and fungi Mostly unicellular, complex cellular organization

Question 34

Nutritional Strategies of Protists

Answer 34

Photoautotrophs, heterotrophs, mixotrophs

Question 35

Mixotrophs

Answer 35

Capable of photosynthesis and heterotrophy

Question 36

Ancestral Eukaryotic Traits

Answer 36

- Nucleus, membrane-bound organelles - Aerobic respiration - Mitochondria from primary endosymbiosis

Question 37

What is the shared derived trait of archaeplastida?

Answer 37

Chloroplasts via primary endosymbiosis - Ancestral archaeplastids participated participated in secondary endosymbiosis

Question 38

ARCHAEPLASTIDA (what is included)

Answer 38

Red algae, green algae (chlorophytes, charophytes), land plants (ALL PHOTOSYNTHETIC)

Question 39

Red Algae

Answer 39

ARCHAEPLASTIDA - Primarily multicellular, often highly branched - Red due to phycoerythrin - Absorb blue, green light - Many live very deep - Usually warm, tropical water

Question 40

Green Algae (Chlorophytes and Charophytes)

Answer 40

ARCHAEPLASTIDA - Closely related to land plants- very similar chloroplasts - Many forms- unicellular, colonial 2 main groups Chlorophytes- mostly freshwater Charophytes- clade that contains plants

Question 41

SAR

Answer 41

Grouped based on genetic evidence Shared derived trait: Secondary endosymbiosis of red algae Includes 3 major clades: Stramenopiles, Alveolates, Rhizarians

Question 42

Stramenopiles

Answer 42

SAR Shared derived traits: Often have flagellum with hair-like projections Often paired with "smooth" flagellum 3 main groups: (all photosynthetic) - Diatoms - Golden algae (TINY) - Brown algae- multicellular

Question 43

Alveolates

Answer 43

SAR Shared derived trait: Alveoli: Flattened vesicles just inside plasma membrane- support membrane Several large and important groups: - Dinoflagellates - Apicomplexans - Ciliates

Question 44

Rhizarians

Answer 44

SAR Shared derived trait: Genetic similarities Often have protective shells of calcium or silica Radiolarians Foraminiferans Cercozoans Important geologically

Question 45

Amoebozoans

Answer 45

Typical "blob" shape Lobe- or tube- shaped pseudopodia Slime molds- not fungi Entamoebas- free-living or parasitic

Question 46

Opisthokonta

Answer 46

Diverse group Includes animals, fungi, several groups of protists Nucleariids- protists, closely related to fungi Choanoflagellates- unicellular, closely related to animals

Question 47

Discoba

Answer 47

Extremely diverse Shared derived traits: Crystalline rod in flagella Some have secondary plastids via green algae- mixotrophic Trypanosomes and Euglenids