Eukaryotic Cells Chapter 27

Question 1

eukaryotes can change shape because of

Answer 1

flexibility in cytoskeleton

Question 2

dynamic cytoskeleton allows for

Answer 2

endocytosis

Question 3

in eukaryotic cells, energy metabolism is localized in

Answer 3

mitochondria/chloroplasts

Question 4

eukaryotes are limited in how they get carbon and energy because

Answer 4

mito-aerobic respiration and photosynthesis

Question 5

why is it a big deal that eukaryotes can engulf larger foodstuffs?

Answer 5

it increases their complexity between organisms

Question 6

where does eukaryotic diversity come from?

Answer 6

being able to replicate multiple strands of DNA that not only code for proteins but also gene expression

Question 7

why did unicellular eukaryotes do so well?

Answer 7

b/c they could remodel cell shape, regulate genes well, all which led to evolving complex life cycle & diff cell types

Question 8

__ promotes genetic diversity in eukaryotes & gives rise to distinctive life cycle

Answer 8

sex

Question 9

asexual organisms use __ to reproduce, but some organisms ____ until conditions improve

Answer 9

mitosis; fuse into diploid (zygote)

Question 10

diatoms

Answer 10

exist as diploid
reproduce asexually
get smaller & then meiosis triggered to produce haploid gametes
most diverse stramenopiles
silica skeletons
account for 1/2 of photosynthesis in the sea

Question 11

chloroplasts originated as

Answer 11

cyanobacteria

-was a form of endosymbiosis

Question 12

chloroplasts have small genomes because

Answer 12

many transported to nucleus-nucleus could supply the chloroplasts’ requirements

Question 13

mitochondria originated as

Answer 13

endosymbiotic bacteria: proteobacteria

Question 14

mitochondria have small genome because

Answer 14

it migrated to the nucleus

Question 15

hydrogenosomes and mitosomes originated as

Answer 15

mitochondria but deal with anaerobic environments

Question 16

what are the 2 hypotheses for how the eukaryotic cell originated?

Answer 16

• eukaryote resembles archaea b/c host for mito-producing endosymbiosis
• euk cell entirely started as symbiotic association between proteobacterium & archaeon

Question 17

protists

Answer 17

have nucleus but lack all else animals, plants & fungi have

Question 18

algae

Answer 18

photosynthetic protists

Question 19

protozoa

Answer 19

heterotrophic protists

Question 20

which is the most diverse eukaryotic superkingdom?

Answer 20

ours, opisthokonts

Question 21

opisthokonts

Answer 21

animals, fungi and some protists

• flagellum movement
• heterotrophic
• animals most sophisticated

Question 22

which is most related to animals?

Answer 22

choanoflagellates

Question 23

microsporadia

Answer 23

single-celled opisthokonts that infect host

-closely related to fungi

Question 24

amoebas move by

Answer 24

pseudopodia

Question 25

most amoebas stay

Answer 25

in the soil to attack other microorganisms

-others attack people

Question 26

plasmodial slime molds

Answer 26

haploid cells fuse to form zygotes that keep doing mitosis but NOT cell division (coenocytic)

Question 27

coenocytic

Answer 27

have many nuclei within one giant cell

Question 28

starvation causes cellular slime molds to

Answer 28

aggregate into a slug–>sporangia–>disperse

Question 29

archaeplastids include ____

how old are they?

Answer 29

land plants

1200 my

Question 30

archaeplastids are the ___ most diverse

Answer 30

second after opisthokonts

Question 31

which organism contains the most ancestral cyanobacterial endosymbiont features than any other algae?

Answer 31

glaucocystophytes

Question 32

red algae

Answer 32

walls made of cellulose

their primary pigments are chlorophyll & biliproteins

Question 33

green algae

Answer 33

big features: chlorophyll a & b in chloroplasts that have 2 membranes and a unique attachment for flagella

Question 34

what are the two branches of green algae?

Answer 34

chlorophytes

-streptophytes

Question 35

streptophytes

Answer 35

more important for humans b/c diversified in fresh water and then made it to land
unicells–>cell clusters–>filaments on intermediate branches–>complex multicellular algae

Question 36

which 3 superkingdoms dominate eukaryotic diversity in the oceans?

Answer 36

stramenopiles, alveolates and rhizarians

Question 37

stramenopiles

Answer 37

unicellular
kelps, algae, protozoa
free-living cells/parasites
2 flagellae
-most photosynthetic: brown algae & diatoms

Question 38

alveolata

Answer 38

photosynthetic and heterotrophic species
have small vesicles (cortical alveoli) store calcium ions
-also include protists called ciliates

Question 39

photosynthetic alveolates belong to

Answer 39

dinoflagellates

Question 40

red tide

Answer 40

when nutrients are supplied to coastal waters in large amounts (toxic)

Question 41

apicomplexans

Answer 41

group of alveolates that cause malaria

Question 42

how did photosynthesis spread through eukaryotes?

Answer 42

repeated endosymbioses involving eukaryotic algae

Question 43

eukaryotes appropriated ___ from cyanobacteria and spread it via ___

Answer 43

oxygenic photosynthesis; horizontal transfer

Question 44

how long have eukaryotes been around?

Answer 44

1800 mya

Question 45

why did more diversity come about in 800-700 mya?

Answer 45

more diversity because b/c protists evolved eating other protists as well as oxygen content of seawater increasing

Question 46

what happened around 252-266 mya?

Answer 46

most significant changes occurred among photosynthesizers

-new ones came about: dinoflagellates and cocclithophorid algae and diatoms

Question 47

list all 7 superkingdoms

Answer 47

opisthokonts
amoebozoans
archaeplastids
stramenopiles
alveolates
rhizarians
excavates