LECTURE 9

Question 1

what is endosymbiosis:

Answer 1

relationship were one lives inside a host

Question 2

the ___ and ___ were derived from prokaryotes but were englufed by a ___ cell
became the:

Answer 2

mitochrondria + Plastids
by eukaryotic cell
became the mitochindrion

Question 3

how did we determine which prokaryotic lineage gave rise to mitochondria?

Answer 3

comparing mtDNA
potentially from: alpha proteobacterium

Question 4

the endosymbiosis explains:

Answer 4

where mitochondria and plastids come from

Question 5

what is the best evidence for secondary emdosymbiosis?

Answer 5

nucleomorph

in the the chlorarachniophytes (Rhizaria) and cryptomonads

Question 6

what does cytoskeleton allow in eukaryotes:

Answer 6

enables eukaryotic cells to change their shape and thereby surround and engulf other cells.

Question 7

the ancestor of mitochondria were : (3)

Answer 7

aerobic
heterotrophic
prokaryotes

Question 8

supporting evidence of endosymbiosis? (4)

Answer 8

1. genome is circular (unlike eukaryotes that have histones)
2. they have their own DNA production/protein machinery
3. size/protein/RNA ensitivity to ab: ribosomes in. mitochondria/plastids are more similar to bacteria than eukaryotes
4. inner membrane has transport proteins similar to bacteria

Question 9

an ___ engulfs an ___ ___ bacterium (___ ____)

produces:

Answer 9

aerobic
heterotrophic bacterium
(alpha proteobacteria)

produces a heterotrophic eukaryote

Question 10

how is a heterotrophic eukaryote formed?

Answer 10

An anaerobe engulfs an aerobic heterotrophic bacterium (alpha proteobacteria) – mitochondria

Question 11

how is a photosynthetic eukaryote formed

Answer 11

Mutualistic aerobe engulfs a gram-negative cyanobacterium – plastid

Question 12

the secondary endosymbiosis started from:

Answer 12

red and green algea

Question 13

evidence for heterotrophic eukaryote that engulfed a green alga:

Answer 13

Evidence for this process can be found within the engulfed cell, which contains a tiny vestigial nucleus, called a nucleomorph

Question 14

best evidence for secondary endosymbiosis? (2)

Answer 14

1. additional vestigial nucleus (nucleomorph)
2. more than 2 membranes around the plastids

Question 15

the first eukaryote us caractegorized as: ___

Answer 15

a protist

Question 16

protists have incredible: ___

Answer 16

structural diversity

Question 17

protist are the most ___ ___

Answer 17

diverse eukaryotes

Question 18

most prostist are ___

Answer 18

unicellular

Question 19

occasionally some protists are ___ and are the ___ organisms on earth

Answer 19

multicellular
biggest organisms on earth
ex: gian kelp/brown algae

Question 20

2 types of nutrition of protists?

Answer 20

chemoheterotrophs and photoautotrophs
also mixotrophs

Question 21

what are mixotrophs

Answer 21

capable of both photosynthesis and heterotrophy

Question 22

how do protists obtain energy? (3)

Answer 22

1. ingestive heterotrophs (animal-like)
2. absorptive heterotrophs (fungus-like)
3. photoautoptrophs (plant-like)

Question 23

what are the 4 supergroupgs of protists? and 2 uncategorized groups

Answer 23

excavate, SAR, acrcheplastida and unikonta

unresolved: haptophytes and chrytophytes

Question 24

diatoms and brown algae are part of which group?

Answer 24

SAR
stramenopiles

Question 25

red and green algae are part of which group

Answer 25

Archaeplastidia

Question 26

How can diatoms produce 20% of the earth’s oxygen when they only make up a small fraction of the earth’s biomass compared to plants?

Answer 26

because of the difference between stock and flow, most plant biomass is wood and roots which does not photosythesize

Question 27

what is "flow"?

Answer 27

the production of oxygen at any given time

Question 28

diatoms are ___ phytoplankton with ___-like ___ shells

Answer 28

diatoms are unicellular phytoplankton with glass-like silica shells

Question 29

diatoms have a structure that:

Answer 29

is glass like and has 2 parts protects them from predators jaw because can resist high pressures

Question 30

diatoms produce:

Answer 30

20% of earth's oxygen

Question 31

which protist does alternation of generations?

Answer 31

brown algae

Question 32

brown algae are ___cellular, ___ and includes:

Answer 32

multicellular marine kelp and seaweeds

Question 33

archaeplastida is a ___ that descended from:

Answer 33

clade ancestral **protist** that engulfed a **cyanobacterium**

Question 34

which protist contains phycoerythrin?

Answer 34

red algae

Question 35

red algea is commonly ___

Answer 35

eaten

Question 36

3 mechanisms through which green algae became multicellular (larger and complexer)

Answer 36

1. formation fo colonies of individual cells 2. multinucleate supercell: repeated division of nuclei with no cytoplasmic division 3. The formation of true multicellular bodies by cell divi- sion and differentiation

Question 37

volvox:

Answer 37

colonies of individual cells

Question 38

caulerpa:

Answer 38

multinucleate supercell (no cytoplasmic division)

Question 39

ulva:

Answer 39

true multicellularity through cell division and diff.

Question 40

slime molds produce:

Answer 40

fruiting bodies

Question 41

classification of slime molds?

Answer 41

unikonta -> amoebozoan

Question 42

# cellular slime mold when is it asexually reproducing?

Answer 42

during multicelled conditions, when food is depleted cells form a slug-like aggregate that functions as a unit

Question 43

# cellular slime mold when is it sexually reproducing?

Answer 43

during single-celled conditions, when food conditions are good during feeding stage solitary cells function individually

Question 44

3 reasons wy slime molds are interesting to study:

Answer 44

* simple multi-cellular system, with cellular specialization (stalk, fruiting cells) * How multicellularity might arise from unicellular systems * Simple system to study how cells signal (how do slime molds know that food is limiting?)

Question 45

Rhizarians are a diverse group of protists defined by ___

Answer 45

DNA similarities

Question 46

purpose of cilia in alveolates? (2)

Answer 46

Cilia for movement & feeding (phagocytosis)

Question 47

distinctive feature of CILIATES?

Answer 47

macro and micro nuclei

Question 48

genetic variation in ciliates comes from:

Answer 48

CONJUGATION

Question 49

what is conjugation in ciliates?

Answer 49

exchange of haploid micronuclei

Question 50

rhizaria is a ___ ___

Answer 50

monopyletic clade

Question 51

amoebas feed and move by ____

Answer 51

pseudopodia

Question 52

Rhizarians include ___ and ___

Answer 52

Rhizarians include forams and radiolarians

Question 53

# symbiont protist give 2 examples where a protist benefits its host?

Answer 53

- Dinoflagellates nourish coral polyps that build reefs – Hypermastigotes digest cellulose in the gut of termites

Question 54

protists are also ?

Answer 54

prducers photosythetic

Question 55

parasitic protist:

Answer 55

plasmodium causes malaria

Question 56

2 uses of sweaweed

Answer 56

commodities and food

Question 57

are protist are monophyletic group?

Answer 57

No, polyphyletic group, some of its members have different ancestors

Question 58

although they are ___ protist are much ___ than prokaryotes

Answer 58

unicellular larger

Question 59

6 things that define EUKARYOTES as opposed to prokaryotes:

Answer 59

1. Genetic material in the **nucleus** 2. **Mitochondria** 3. Other **membrane-bound organelles** (e.g. golgi bodies, plastids) 4. **Cytoskeleton** 5. **Monophyletic** group 6. (Generally) capable of **sexual reproduction** via meiosis

Question 60

name a key feature of eukaryotes?

Answer 60

self-reproducing organelles