Deck 20: The Origin and Diversification of Eukaryotes

Question 1

Which of the following are not monophyletic?

A) Diplomonads
B) Microbial eukaryotes
C) Animals
D) Red algae
E) Plants

Answer 1

B

Question 2

A prokaryotic cell with a firm cell wall is limited in terms of how large it can get,while eukaryotic cell with a flexible cell membrane is able to grow much larger.What is the significance of this flexible cell membrane in eukaryotes?

A) It means there are no surface area-to-volume constraints on a eukaryotic cell.
B) It allows for infolding,which increases surface area of eukaryotes.
C) It allows for eukaryotic cells to be larger to contain their mitochondria.
D) Eukaryotes have a cytoskeleton,which allows for a smaller surface area-to-volume ratio.
E) It allows eukaryotic cells to grow larger to accommodate food vacuoles.

Answer 2

B

Question 3

The increasing concentration of oxygen in Earth's early atmosphere

A) was favorable to numerous prokaryotes because of their flexible membranes.
B) was fatal to numerous eukaryotes because of their mitochondria.
C) conferred a selective advantage on eukaryotes that possessed mitochondria.
D) conferred a selective advantage on eukaryotes that possessed chloroplasts.
E) conferred a selective advantage on prokaryotes because of their stiff membranes.

Answer 3

C

Question 4

Which group includes species that form large toxic red tides in the ocean?

A) Foraminiferans
B) Dinoflagellates
C) Kinetoplastids
D) Paramecium
E) Euglena

Question 5

The chloroplasts of red algae retain certain pigments of the original cyanobacterial endosymbiont that are absent in green algal chloroplasts.The evolutionary significance of this is that

A) red algae cannot photosynthesize,leading to heterotrophy.
B) neither green algae nor red algae can be classified as protists.
C) chloroplasts likely originated as free-living cyanobacteria.
D) red algae are classified as cyanobacteria.
E) red algae are classified as prokaryotes.

Question 6

The many organisms designated as "protists" or "microbial eukaryotes"

A) are closely related to the bacteria.
B) are highly diverse and not necessarily closely related to one another.
C) form a monophyletic clade.
D) are all unicellular.
E) are all microscopic.

Question 7

The ability of protists to increase the surface area for gas and nutrient exchange is conferred by

A) mitochondria.
B) a cytoskeleton.
C) a nucleus.
D) a cell wall.
E) a flexible cell membrane.

Question 8

Which step was essential in the evolution of eukaryotic cells?

A) The development of a nuclear envelope
B) The development of a cytoskeleton
C) The endosymbiotic acquisition of certain organelles
D) The development of a flexible cell surface
E) All of the above

Question 9

Microbial eukaryotes are ecologically and evolutionarily important for many reasons.Which statement about this group is false?

A) Multicellular groups evolved from microbial eukaryotes.
B) Photosynthetic microbial eukaryotes play a major role in the energy balance of the living world.
C) There are no parasitic forms of microbial eukaryotes.
D) Saprobic microbial eukaryotes are among the important decomposers and thus play a major role in the nutrient cycles of the living world.
E) Many microbial eukaryotes have highly differentiated bodies,even though they consist of only one cell.

Question 10

The overall size that unicellular microbial eukaryotes can achieve is limited by their

A) energy-producing potential.
B) metabolism.
C) mitochondria.
D) surface area-to-volume ratio.
E) chloroplasts.

Question 11

The _______ are a group of protists that harbor photosynthetic and accessory pigments that make them look golden brown in color.

A) dinoflagellates
B) plasmodial slime molds
C) radiolarians
D) oomycetes
E) corals

Question 12

What feature of eukaryotes makes endosymbiosis possible?

A) Nuclear membrane
B) Mitochondria
C) Flexible cell membrane
D) Digestive vacuoles
E) Flagella

Question 13

Apicomplexans

A) possess flagella in all phases of the life cycle.
B) possess a glassy shell.
C) are all parasitic.
D) are algae.
E) include the trypanosomes that cause sleeping sickness.

Question 14

The photosynthetic euglenids obtained their chloroplasts,which are surrounded by three membranes,through

A) secondary endosymbiosis,retaining the chloroplast from a green alga.
B) primary endosymbiosis.
C) secondary endosymbiosis,retaining the chloroplast from a blue-green alga.
D) tertiary endosymbiosis.
E) None of the above

Question 15

Which characteristic represents a synapomorphy (shared derived trait)of the alveolates?

A) The presence of peptidoglycan between membranes of an important organelle
B) Rows of tubular hairs on the longer of two unequally sized flagella
C) Air sacs below the cell membrane
D) A fully parasitic lifestyle
E) External shells of calcium carbonate

Question 16

Dinoflagellates are common endosymbionts of

A) corals.
B) fungi.
C) other dinoflagellates.
D) tertiary endosymbionts.
E) diatoms.

Question 17

Our current understanding of the evolutionary relationship among the five major groups of protists is

A) uncertain,or at most weakly supported.
B) strongly supported by morphological data.
C) strongly supported by genomic data.
D) somewhat supported by fossil data.
E) impossible to determine.

Question 18

Ribosomal RNA (rRNA)genes are present in the

A) mitochondria.b.a cytoskeleton.c.a nucleus.d.a cell wall.e.a flexible cell membrane.
B) mitochondrial genomes of eukaryotes.
C) chloroplast genomes of plants.
D) genomes of bacteria.
E) All of the above

Question 19

Plasmodium,the organism that causes malaria,is a(n)

A) turbellarian.
B) mastigophoran.
C) dinoflagellate.
D) apicomplexan.
E) poriferan.

Question 20

Which group includes the dinoflagellates?

A) Alveolates
B) Green algae
C) Red algae
D) Stramenopiles
E) Euglenozoans

Question 21

Members of which group are thought to be the closest relatives of the animals?

A) Euglenozoans
B) Choanoflagellates
C) Stramenopiles
D) Alveolates
E) Chlorophytes

Question 22

Which pair does not share the same relationship as alveolates and dinoflagellates?

A) Stramenopiles and diatoms
B) Rhizarians and radiolarians
C) Excavates and diplomonads
D) Amoebozoans and loboseans
E) Apicomplexans and ciliates

Question 23

Which group is not considered to belong among the protists?

A) Diatoms
B) Red algae
C) Slime molds
D) Sponges
E) Giant kelp

Question 24

Which structure is not associated with Paramecium?

A) Digestive vacuole
B) Oral groove
C) Cilium
D) Pseudopod
E) Alveolus

Question 25

Two different species of ciliate are placed in a solution with an unknown solute concentration.Ciliate A has a contractile vacuole that expels water at a rate of 5 times per minute;the contractile vacuole of ciliate B expels water 12 times per minute.What is a reasonable conclusion based on these observations?

A) Ciliate A has a greater solute concentration than ciliate B.
B) Ciliate B has a greater solute concentration than ciliate A.
C) The solution has a greater solute concentration than ciliate A.
D) The solution has a greater solute concentration than ciliate B.
E) No conclusions can be made unless we know the solute concentration of the solution.

Question 26

Microbial eukaryotes with flagella

A) occur in several major clades.
B) are all algae.
C) all have pseudopods.
D) are all colonial.
E) are never pathogenic.

Question 27

Which group is not a member of the ophisthokonts?

A) Fungi
B) Brown algae
C) Mammals
D) Choanoflagellates
E) Fish

Question 28

The microbial eukaryotes that are responsible for sleeping sickness and those that are responsible for malaria

A) are both alveolates.
B) both have gametocyte life stages.
C) cause the same symptoms.
D) both have insect vectors for transmission to humans.
E) are both trypanosomes

Question 29

Which of the following represents a synapomorphy (shared derived trait)of the stramenopiles?

A) The presence of peptidoglycan between membranes of an important organelle
B) A fully parasitic lifestyle
C) Air sacs below the cell membrane
D) Rows of tubular hairs on the longer of two unequally sized flagella
E) External shells of calcium carbonate

Question 30

Which group of protists secretes an external "shell" of silica (silicon dioxide)?

A) Diatoms
B) Paramecium
C) Red algae
D) Euglenids
E) Amoebozoans

Question 31

Which clade of eukaryotes includes groups that do not have mitochondria?

A) Alveolates
B) Plantae
C) Excavates
D) Rhizaria
E) Stramenophiles

Question 32

Which group contains giant kelps and other multicellular brown algae?

A) Apicomplexans
B) Fungi
C) Stramenopiles
D) Alveolates
E) Euglenids

Question 33

Which statement does not apply to diatoms?

A) The cell walls are often impregnated with silica.
B) During mitosis,the top and bottom of the cell become the tops of the two new cells.
C) Protein is the main photosynthetic storage product.
D) Zygotes are formed by gametes that lack cell walls.
E) They can show bilateral or radial symmetry.

Question 34

Foraminiferans secrete an external shell made of _______,whereas diatoms have a shell made of _______.

A) grains of sand;silica
B) chitin;grains of sand
C) calcium carbonate;silica
D) grains of sand;glass
E) silica;calcium carbonate

Question 35

Microbial eukaryotes are found in which habitat(s)?

A) Marine habitats
B) Freshwater aquatic habitats
C) The body fluids of other organisms
D) Damp soil
E) All of the above

Question 36

Which organisms lack mitochondria?

A) Diplomonads
B) Choanoflagellates
C) Red algae
D) Euglenozoans
E) Plasmodial slime molds

Question 37

In terms of their nutritional mode,microbial eukaryotes can be

A) autotrophs.
B) absorptive heterotrophs.
C) photosynthetic.
D) both heterotrophic and autotrophic
E) All of the above

Question 38

Which statement about protists is false?

A) Protists are found only in aquatic habitats.
B) Protists have many different metabolic lifestyles.
C) Some protists use pseudopods or cilia to locomote.
D) Several groups of protists rid themselves of excess water by means of contractile vacuoles.
E) Some protists are parasitic.

Question 39

Which disease is not caused by trypanosomes?

A) African sleeping sickness
B) Malaria
C) Leishmaniasis
D) Chagas' disease
E) All of these diseases are caused by trypanosomes.

Question 40

Which statement about the brown algae is false?

A) They are all multicellular.
B) They use the same photosynthetic pigments as land plants.
C) They are almost exclusively marine.
D) A few are many meters in length.
E) They are stramenopiles.

Question 41

The excavates are a clade of eukaryotes that includes groups without mitochondria.What is the most convincing evidence that this absence of mitochondria is a derived condition resulting from a secondary loss?

A) There is a nuclear membrane in these organisms.
B) The cell membrane of these organisms is flexible and capable of phagocytosis.
C) Some of the nuclear genes of these organisms are normally associated with mitochondria.
D) In euglenids,a group in this clade with mitochondria,the mitochondria have distinctive disc-shaped cristae.
E) Other eukaryote clades have both chloroplasts and mitochondria.

Question 42

The three groups of rhizarians include cercozoans,foraminiferans,and

A) kinetoplastids.
B) diplomonads.
C) stramenopiles.
D) loboseans.
E) radiolarians.

Question 43

Some amoebozoans are composed of coenocytes,which means that

A) they have a single nucleus enclosed in a single cell membrane.
B) their cytoplasm is pigmented.
C) they have multiple nuclei enclosed in a single cell membrane.
D) they feed on dead organic matter.
E) they have multiple flagella on their nonreproductive cells.

Question 44

Which of the following is not a characteristic of the brown algae?

A) Leaflike growths that can be up to 60 meters long
B) Storage of the products of photosynthesis as protein
C) A specialized holdfast that aids in attachment to a surface
D) The presence of the carotenoid fucoxanthin in their chloroplasts
E) Multicellularity

Question 45

A key difference between plasmodial slime molds and cellular slime molds is that

A) only cellular slime molds are motile.
B) they have different numbers of nuclei within each cell membrane.
C) only acellular slime molds ingest food by endocytosis.
D) only cellular slime molds ingest food by endocytosis.
E) acellular slime molds prefer cool,moist habitats,whereas cellular slime molds prefer dry,hot conditions.

Question 46

The _______,members of the phytoplankton,are major photosynthetic producers in coastal waters.

A) radiolarians
B) amoebozoans
C) choanoflagellates
D) diatoms
E) ciliates

Question 47

The _______ include the water molds and mildews.

A) parabasalids
B) apicomplexans
C) red algae
D) euglenids
E) oomycetes

Question 48

The _______ are marine microbial eukaryotes that secrete a glassy endoskeleton.

A) algae
B) protozoa
C) radiolarians
D) flagellates
E) dinoflagellates

Question 49

The cellular slime molds belong to which group?

A) Alveolates
B) Stramenophiles
C) Rhizaria
D) Excavates
E) Amoebozoans

Question 50

You find a fish carcass in a pond and see white filaments radiating from it.Back in the lab,you stain the white filaments and see that they have cell walls made of cellulose.You have most likely found a species what would be classified within the

A) rhizaria.
B) apicomplexans.
C) red algae.
D) euglenids.
E) oomycetes.

Question 51

The signal that is responsible for the aggregation of myxamoebas is

A) the onset of adverse conditions.
B) alginic acid.
C) phycoerythrin.
D) actin.
E) endosymbiosis.

Question 52

Which protist group includes large multinucleate terrestrial heterotrophs that are visible to the naked eye and can be several yards in diameter?

A) Ciliates
B) Euglenids
C) Brown algae
D) Foraminiferans
E) Plasmodial slime molds

Question 53

The clusters of blind-ending,grapelike,hollow structures in the mammalian lung are called "alveoli." Similarly,members of the clade called alveolates typically

A) have two unequal flagella,one with hairs.
B) possess long,thin pseudopods.
C) have lobe-shaped pseudopods.
D) possess sacs just beneath their cell membranes.
E) lack mitochondria.

Question 54

Which group,if eliminated,would decrease global oxygen levels the most?

A) Radiolarians
B) Diplomonads
C) Dinoflagellates
D) Diatoms
E) Apicomplexans

Question 55

Which feature is not a characteristic of the plasmodium of a plasmodial slime mold?

A) Many nuclei enclosed in a single cell membrane (coenocyte)
B) Haploid nuclei
C) Cytoplasmic streaming
D) Mitosis without cytokinesis
E) Formation of a sclerotium when conditions are unfavorable

Question 56

Which group exhibits exclusively radial symmetry?

A) Loboseans
B) Foraminiferans
C) Stramenophiles
D) Radiolarians
E) Heteroloboseans

Question 57

Which event is not normally part of the life cycle of a plasmodial slime mold?

A) Formation of a sclerotium when conditions are adverse
B) Active feeding by the plasmodium as it engulfs food particles
C) Meiosis to form spore-bearing structures
D) Fusion of swarm cells to form a diploid zygote
E) Development of spores into myxamoebas

Question 58

The plasmodial slime molds

A) form a plasmodium that is a coenocyte.
B) lack fruiting structures.
C) consist of large numbers of myxamoebas.
D) consist at times of a mass called a pseudoplasmodium.
E) cannot move from one location to another,as cellular slime molds can.

Question 59

In the cellular slime molds,the onset of adverse conditions causes

A) aggregation of swarm cells to form a plasmodium.
B) formation of sporangia.
C) release of myxamoebas from fruiting bodies.
D) the onset of cytoplasmic streaming.
E) aggregation of myxamoebas to form a slug or pseudoplasmodium.

Question 60

Which group uses pseudopods for locomotion?

A) Euglenids
B) Diatoms
C) Amoebozoans
D) Dinoflagellates
E) Stramenopiles

Question 61

Which statement about brown algae is true?

A) They are specialized to withstand pounding by surf.
B) Their color results from a symbiotic relationship with dinoflagellates.
C) Their fossilized remains make a major contribution to limestone.
D) The fronds are stiffened with silica.
E) Their primary habitat is above the tidal zone on the seashore.

Question 62

You are looking at a plankton sample and find a single-celled organism with an external shell and thin,threadlike pseudopod structures extending through it.This organism is most likely a

A) dinoflagellate.
B) plasmodial slime mold.
C) radiolarian.
D) foraminiferan.
E) diatom.

Question 63

Which process is not part of conjugation in Paramecium?

A) Meiosis
B) Mitosis
C) Cytokinesis
D) Fusion of haploid nuclei
E) Breakdown of some micronuclei

Question 64

Which statement about the micronucleus and macronucleus is false?

A) The micronucleus is a typical eukaryotic nucleus.
B) Genes found in the macronucleus are commonly represented by multiple copies in a cell.
C) Transcription and translation involve genes found mostly in the macronucleus.
D) Ciliates possess both a micronucleus and a macronucleus.
E) The macronucleus is involved in genetic recombination.

Question 65

Which pair is most closely related?

A) Brown algae and diatoms
B) Dinoflagellates and euglenids
C) Oomycetes and plasmodial slime molds
D) Cercozoans and parabasalids
E) Apicomplexans and kinetoplastids

Question 66

You are looking at a plankton sample and find a single-celled organism with a glassy internal skeleton that gives it an elaborate geometric shape.It has a greenish golden color derived from photosynthetic endosymbionts within the organism.This organism is most likely a

A) dinoflagellate.
B) plasmodial slime mold.
C) radiolarian.
D) diatom.
E) coral.

Question 67

Which statement about the process of conjugation in paramecia is false?

A) Macronuclei in the resulting paramecia are genetically different from the macronuclei in the original paramecia.
B) The two resulting paramecia are genetically distinct from each other.
C) Within each paramecium,the original macronucleus is destroyed.
D) The two resulting paramecia have a combination of alleles.
E) The micronuclei that are exchanged are genetically different from each other.

Question 68

Which group does not include human parasites?

A) Apicomplexans
B) Kinetoplastids
C) Heteroloboseans
D) Diplomonads
E) Oomycetes

Question 69

Which reproductive process occurs among the protists (microbial eukaryotes)?

A) Binary fission
B) Multiple fission
C) Budding and spore formation
D) Union of gametes
E) All of the above

Question 70

The ciliates

A) move by means of long flagella.
B) use amoeboid movement.
C) include Plasmodium,the agent of malaria.
D) possess both a macronucleus and micronuclei.
E) are autotrophic.

Question 71

Which organism is not a member of the phytoplankton?

A) Diatom
B) Cyanobacteria
C) Green algae
D) Kinetoplastid
E) Dinoflagellate

Question 72

Which group is least related (i.e. ,most distantly related)to the others?

A) Paramecia
B) Apicomplexans
C) Dinoflagellates
D) Ciliates
E) Trypanosomes

Question 73

Asexually reproduced groups of nearly identical organisms are known as

A) fruiting bodies.
B) buds.
C) clonal lineages.
D) myxamoebas.
E) conjugates.

Question 74

Paramecia contain two types of nuclei: a large macronucleus and usually several micronuclei.The micronuclei are typical eukaryotic nuclei,essential for genetic recombination.The macronucleus

A) is important in sexual recombination (conjugation).
B) contains several micronuclei.
C) contains DNA that is not transcribed.
D) contains many copies of the genetic information.
E) contains DNA that is transcribed but not translated.

Question 75

While out hiking you drink water from a stream,and several days later you feel sick with diarrhea and intestinal bloating.Your doctor collects a stool sample and finds unicellular organisms that lack mitochondria and have multiple flagella.You are most likely infected with

A) the diplomonad Giardia.
B) slime molds.
C) kinetoplastid trypanosomes.
D) the ciliate Paramecium.
E) testate amoebozoans.

Question 76

You are examining a saltwater sample and see a single-celled organism with a cell wall constructed of two pieces,with the top piece overlapping the bottom piece.The cell wall is impregnated with silica and has an intricate pattern.It is most likely that you are looking at a

A) red alga.
B) radiolarian.
C) diatom.
D) euglenid.
E) dinoflagellate.

Question 77

The ancestor of photosynthetic euglenids took up the chloroplast of a green alga.This explains why photosynthetic euglenids

A) have a flagellum.
B) have the same photosynthetic pigments as plants.
C) are ancestral to land plants.
D) have two nuclei.
E) lose their photosynthetic pigments when kept in the dark.

Question 78

If you put an autotrophic Euglena species in pond water and placed it in the dark,what would be the most likely outcome?

A) It would produce an excess of photosynthetic pigment.
B) It would produce an excess of photosynthetic pigment and secrete excess sugar compounds.
C) It would die.
D) It would stop using its chloroplasts to synthesize organic compounds and begin feeding on organic material floating in the pond water.
E) Nothing would happen.

Question 79

If you were to examine limestone deposits throughout the world,which group of organisms would you expect to find in the greatest abundance in these deposits?

A) Foraminiferans
B) Dinoflagellates
C) Radiolarians
D) Heliozoans
E) Trypanosomes

Question 80

Which group has no photosynthetic members?

A) Alveolates
B) Stramenopiles
C) Rhizarians
D) Excavates
E) Amoebozoans