Chapter 25

Question 1

What are the 3 fundamental elements of Eukaryotes?

Answer 1

1. Nucleus
2. Organelles
3. Structurally complex cytoskeleton

Question 2

Protist

Answer 2

informal name for a diverse group of mostly unicellular eukaryotes

Question 3

What does a structurally complex cytoskeleton allow a eukaryote to do?

Answer 3

1. have asymmetrical form
2. move, feed, grow

Question 4

List the 3 stages of eukaryotes.(early records)

Answer 4

1. initial diversification
2. multicellular & appearance of novel features
3. Rise of large eukaryotes

Question 5

List the characteristics of initial diversification

Answer 5

1. single celled
2. all had a nucleus, flexible membrane, and cytoskeleton
3. varied in size and shape

Question 6

List the novel (new) features in the second stage

Answer 6

1. complex multicellularity - organisms had differentiated cell types
2. sexual life cycles
3. photosynthesis

Question 7

List the characteristics in that gave rise to large eukaryotes.

Answer 7

1. body sized maximized
2. increased taxonomic diversity
3. increase types of morphological differences
4. soft bodied

Question 8

Endosymbiosis

Answer 8

symbiotic relationship where one organisms lives in the body or cell of another

Question 9

Plastids

Answer 9

general term for chloroplasts and related organelles

Question 10

Endosymbiont Theory

Answer 10

that mitochondria & plastids were formerly small bacteria that began living within larger cells.

Question 11

Primary endosymbiosis

Answer 11

engulfment of a prokaryote by another living cell and incorporation of that prokaryote as on organelle

Question 12

What stage of endosymbiosis is responsible for the initial eukaryotes mitochondria and chloroplast?

Answer 12

Primary endosymbiosis

Question 13

Serial endosymbiosis hypothesis

Answer 13

suggesting that mitochondria evolved before plastids through a sequence of endosymbiotic events.

Question 14

Secondary endosymbiosis

Answer 14

a eukaryotic cell engulfs a cell that has already undergone primary endosymbiosis.

Question 15

How did secondary endosymbiosis occur?

Answer 15

when photosynthetic eukaryotic algal cells were ingested by heterotrophic eukaryotes.

Question 16

Multicellularity in different eukaryotes arose ___.

Answer 16

independently

Question 17

Multicellular colonies

Answer 17

complex of connected cells with little to no cellular differentiation

Question 18

Complex mutlicellularity

Answer 18

complex of connected cells that are differentiated

Question 19

Co-opting

Answer 19

changes in how existing genes are used rather than addition of new genes

Question 20

List the 4 “Supergroups” of Eukaryotes

Answer 20

1. Excavata
2. SAR
3. Archaeplastida
4. Unikonta

Question 21

List the 3 clades Excavata has

Answer 21

1. Diplomonads
2. Parabasalids
3. Euglenozoans

Question 22

List the characteristics of Dipolomonads

Answer 22

1. Most in anaerobic environments
2. Highly reduced mitochondria called mitosomes
3. Many are parasites

Question 23

Give an example of Dipolomonads

Answer 23

giardia intestinalis - lives in mammals intestines and is found in creek water

Question 24

List the characteristics of Parabasalids

Answer 24

1. most in anaerobic environments
2. highly reduced mitochondria called hydrogenosomes
3. many are animal symbionts or parasites

Question 25

Give an example of parabasalids symbiont and parasite.

Answer 25

Its a gut mutualist in termites human parasite called trichomonas vaginalis

Question 26

List the characteristics of Euglenozoans

Answer 26

1. highly diverse (hetetrophs, autotrophs, parasites) 2. flagella with spiral or crystalline structure

Question 27

What kind of "troph" is euglenozoans?

Answer 27

Mixotroph - meaning it can switch how it obtains energy

Question 28

Give examples of Euglenozoans

Answer 28

1. euglenid - african sleeping sickness from being bitten by flies 2. kinetoplastid

Question 29

List the 3 groups of SAR

Answer 29

1. Stramenopiles 2. Alveolates 3. Rhizarians

Question 30

List the characteristics of Stramenopiles

Answer 30

1. evolved via secondary endosymbiosis 2. vital photosynthetic organisms

Question 31

List the two groups under stramenopiles

Answer 31

1. diatoms 2. brown algae "sea weed"

Question 32

What do diatoms form ?

Answer 32

the bases of the food web

Question 33

List the characteristics of Diatoms

Answer 33

1. unicellular algae with glass like (silicon dioxide) cell wall 2. most abundant photosynthetic organism in aquatic & marine systems 3. Has significant effects on global CO2

Question 34

List the characteristics of Brown Algae or Sea Weed

Answer 34

1. largest, most complex of all algae 2. all are multicellular 3. most are marine 4. Plant like structures but are NOT plants 5. Pneumotocsys - gas filled floats

Question 35

List the characteristics of Alevolates

Answer 35

1. likely evolved via secondary endosymbiosis 2. have membrane - enclosed sacs called alveoli

Question 36

what is alveoli?

Answer 36

membrane enclosed sacs

Question 37

List the two groups under Alveolates.

Answer 37

1. dinoflagellates 2. ciliates

Question 38

list the characteristics of Dinoflagellates

Answer 38

1. habitat is in aquatic & marine systems 2. cells are armored with cellulose plates 3. have 2 flagella 4. some are mixotrophs - photosynthetic + heterothrophic

Question 39

What is caused by dinoflagellates?

Answer 39

Red tide due to extreme population growth can make the ocean light (blue colored)

Question 40

List the characteristics of ciliates.

Answer 40

1. use cilia (hair like) to move + feed 2. most are predators of bacteria + other protists 3. their structure varies among organisms

Question 41

List the characteristics of Rhizarians

Answer 41

1. many are amoebas but not all amoebas are rhizarians 2. amoebas move and feed by pseudopodia, extensions that bulge from the cell surface.

Question 42

List the 2 groups under Rhizarians

Answer 42

1. Forams 2. Cercozoans

Question 43

List the characteristics of Forams

Answer 43

1. have porous shells called tests 2. found in aquatic + marine systems 3. the hair like extensions called pseudopodia extend through holes in tests that help it swim, feed, and formation 4. many are in symbiosis with photosynthetic algae

Question 44

List the characteristics of Cerozoans

Answer 44

1. group consisting of ameboid + flagellated protists that feed with threadlike pseudopodia 2. found in marine, freshwater, and soil 3. most are heterotrophic but some are autotrophs and mixotrophs 4. parasitic symbiosis - predators

Question 45

what group is the most abundant in moist soil?

Answer 45

cercozoans

Question 46

List the 3 groups under Archaeplastida

Answer 46

1. Red Algae 2. Green algae 3. Plants

Question 47

List the characteristics of Red Algae

Answer 47

1. coloration due to accessory pigment in phycoerythrin (varies with depth) 2. Most are multicellular 3. Largest are seaweed 4. sexual reproduction

Question 48

Give an example of red algae

Answer 48

nori (sea weed thats wrapped in sushi)

Question 49

List the two groups under Green algae

Answer 49

1. charophytes -closely related to plants 2. Chlorophytes

Question 50

List the characteristics of Chlorophytes

Answer 50

1. more than 7,000 species 2. most are in freshwater but some are found in marine or terrestrial 3. most reproduce sexually with bi-flagellated gametes 4. mix of unicellular and multicellular

Question 51

List the 2 major groups (or clades) under Unikonts

Answer 51

1. Opisthokonts 2. Amoebozoans

Question 52

What is included in Opisthokonts?

Answer 52

1. animals 2. fungi 3. some protists

Question 53

List the characteristics of Amoebozoans

Answer 53

1. lobe shaped or tube shaped pseudopodia 2. most are hetetrotrophs but some are detritives

Question 54

what are detritives?

Answer 54

under the clade of amoebozoans and feed on dead organic organisms or a bi-product of organisms

Question 55

What are the two major groups under Amoebozoans?

Answer 55

1. Tubulinids 2. Slime molds

Question 56

List the characteristics of Tubulinids.

Answer 56

1. unicellular 2. common in soil, freshwater, marine 3. nickelodeon shaped

Question 57

List the characteristics of Slime molds

Answer 57

1. multicellular 2. produce spores 3. once believed to be fungi

Question 58

Where are protists found?

Answer 58

freshwater and marine systems and also on moist terrestrial habitats

Question 59

Protists exhibit what types of ways of obtaining energy

Answer 59

1. photoautotrophy 2. hetetrotrophy 3. mixotrophy

Question 60

The chloroplasts of all of the following are thought to be derived from ancestral red algae, except those of

Answer 60

green algae

Question 61

In a sample of pond water, a new organism is identified with the following characteristics: It consists of 70 cells surrounded by rigid cell walls that join the cells together. Inside each of these identical cells are mitochondria and chloroplasts. Such an organism would most likely be classified as a

Answer 61

colonial photosynthetic eukaryote.

Question 62

Healthy individuals of Paramecium bursaria contain photosynthetic algal endosymbionts of the genus Chlorella. When within their hosts, the algae are referred to as zoochlorellae. In aquaria with light coming from only one side, P. bursaria gathers at the well-lit side, whereas other species of Paramecium gather at the opposite side. The zoochlorellae provide their hosts with glucose and oxygen, and P. bursaria provides its zoochlorellae with protection and motility. P. bursaria can lose its zoochlorellae in two ways: (1) if kept in darkness, the algae will die; and (2) if prey items (mostly bacteria) are absent from its habitat, P. bursaria will digest its zoochlorellae. Which term best describes the symbiotic relationship of well-fed P. bursaria with their zoochlorellae?

Answer 62

mutualistic (each species benefits from the other)

Question 63

Rhizarians that feed using threadlike pseudopodia include which of the following group(s)? I. forams II. red algae III. cercozoans IV. green algae

Answer 63

forams and cercozoans

Question 64

In a synthetic biology experiment, you are given a task to design a new species of aquatic protist. Your design should account for the following characteristics: 1. The protist functions as a primary producer. 2. It cannot swim on its own. 3. It must stay in well-lit surface waters. 4. It must be resistant to physical damage from wave action. Based on these criteria, you decide to model your creation after a(n)

Answer 64

Diatom

Question 65

An individual mixotroph loses its plastids yet continues to survive. Which of the following most likely accounts for its continued survival?

Answer 65

It engulfs organic material by phagocytosis or by absorption.

Question 66

What does scientific evidence indicate to be the correct sequence of these events, from earliest to most recent, in the evolution of life on Earth? 1. origin of mitochondria 2. origin of multicellular eukaryotes 3. origin of chloroplasts 4. origin of cyanobacteria 5. origin of fungal-plant symbioses

Answer 66

4, 1, 3, 2, 5

Question 67

According to the endosymbiotic theory of the origin of eukaryotic cells, how did mitochondria originate?

Answer 67

from engulfed, originally free-living proteobacteria