Question 1

Which of the following groups is matched with a correct anatomical feature?

Accepted Answer

A)  foraminifera-silicon-rich tests 
B)  dinoflagellata-holdfast 
C)  diatoms-tests made of cellulose 
D)  brown algae-blade 
A)  foraminifera-silicon-rich tests 
B)  dinoflagellata-holdfast 
C)  diatoms-tests made of cellulose 
D)  brown algae-blade

Question 2

Diatoms are mostly asexual members of the phytoplankton. Diatoms lack any organelles that provide for locomotion. They obtain their nutrition from functional chloroplasts, and each diatom is encased within two porous, glasslike valves. Which question would be most important for one interested in explaining the day-to-day survival of individual diatoms?

Accepted Answer

A)  How do diatoms move from one location on the water's surface layers to another location on the surface? 
B)  How do diatoms with their glasslike valves keep from sinking into poorly lit waters? 
C)  How do diatoms with their glasslike valves avoid being shattered by the action of waves? 
D)  How do diatom sperm cells locate diatom egg cells? 
A)  How do diatoms move from one location on the water's surface layers to another location on the surface? 
B)  How do diatoms with their glasslike valves keep from sinking into poorly lit waters? 
C)  How do diatoms with their glasslike valves avoid being shattered by the action of waves? 
D)  How do diatom sperm cells locate diatom egg cells?

Question 3

According to the phylogeny presented in this chapter, which protists are in the same eukaryotic supergroup as plants?

Accepted Answer

A)  green algae 
B)  dinoflagellates 
C)  red algae 
D)  both A and C 
A)  green algae 
B)  dinoflagellates 
C)  red algae 
D)  both A and C

Question 4

Plastids that are surrounded by more than two membranes are evidence of ________.

Accepted Answer

A)  evolution from mitochondria 
B)  fusion of plastids 
C)  origin of the plastids from archaea 
D)  secondary endosymbiosis 
A)  evolution from mitochondria 
B)  fusion of plastids 
C)  origin of the plastids from archaea 
D)  secondary endosymbiosis

Question 5

Living diatoms contain brownish plastids. If global climate change continues to warm surface waters of Earth's oceans, which of the following is the most likely effect on the animals that build coral reefs?

Accepted Answer

A)  The coral animals, which capture planktonic organisms, may be outcompeted by the diatoms. 
B)  The coral animals' endosymbiotic dinoflagellates may get "shaded out" by the diatoms. 
C)  The coral animals may die from overeating the plentiful diatoms with their cases of silica. 
D)  The diatoms' photosynthetic output may over-oxygenate the water. 
A)  The coral animals, which capture planktonic organisms, may be outcompeted by the diatoms. 
B)  The coral animals' endosymbiotic dinoflagellates may get "shaded out" by the diatoms. 
C)  The coral animals may die from overeating the plentiful diatoms with their cases of silica. 
D)  The diatoms' photosynthetic output may over-oxygenate the water.

Question 6

Which group is correctly paired with its description?

Accepted Answer

A)  diatoms-important consumers in aquatic communities 
B)  diplomonads-protists with modified mitochondria 
C)  apicomplexans-producers with intricate life cycles 
D)  red algae-acquired plastids by secondary endosymbiosis 
A)  diatoms-important consumers in aquatic communities 
B)  diplomonads-protists with modified mitochondria 
C)  apicomplexans-producers with intricate life cycles 
D)  red algae-acquired plastids by secondary endosymbiosis

Question 7

Which of the following characteristics is common among all protists?

Accepted Answer

A)  unicellular 
B)  eukaryotic 
C)  symbionts 
D)  mixotrophic 
A)  unicellular 
B)  eukaryotic 
C)  symbionts 
D)  mixotrophic

Question 8

A porous test (shell) of calcium carbonate, through which pseudopodia protrude, is characteristic of which of the following groups of organisms?

Accepted Answer

A)  diatoms 
B)  foraminiferans 
C)  ciliates 
D)  water molds 
A)  diatoms 
B)  foraminiferans 
C)  ciliates 
D)  water molds

Question 9

Many parasitic members of the excavates lack plastids and have highly reduced mitochondria. Which of the following statements explains these observations?

Accepted Answer

A)  These parasites typically live in low-oxygen conditions, and therefore it was adaptive to move all plastid and mitochondrial genes to the nucleus. 
B)  The original, eukaryotic ancestors of these parasites did not engulf prokaryotes. 
C)  These parasites typically live in low-oxygen conditions and therefore loss of genes for plastids and mitochondria did not result in lower fitness. 
D)  In the future, natural selection will favor descendants that acquire new plastid genes from today's prokaryotes. 
A)  These parasites typically live in low-oxygen conditions, and therefore it was adaptive to move all plastid and mitochondrial genes to the nucleus. 
B)  The original, eukaryotic ancestors of these parasites did not engulf prokaryotes. 
C)  These parasites typically live in low-oxygen conditions and therefore loss of genes for plastids and mitochondria did not result in lower fitness. 
D)  In the future, natural selection will favor descendants that acquire new plastid genes from today's prokaryotes.

Question 10

Which of the following results would be most likely if a layer of warm, light water caused by ocean surface warming blocks nutrient upwelling?

Accepted Answer

A)  reduced populations of fish because they avoid warm water 
B)  increased populations of producers because they have access to more CO2 
C)  reduced populations of producers because they have access to fewer nutrients 
D)  increased populations of producers because fewer fish are produced, and they eat fewer producers 
A)  reduced populations of fish because they avoid warm water 
B)  increased populations of producers because they have access to more CO2 
C)  reduced populations of producers because they have access to fewer nutrients 
D)  increased populations of producers because fewer fish are produced, and they eat fewer producers

Question 11

When a mosquito infected with Plasmodium first bites a human, what is the first process carried out by the Plasmodium?

Accepted Answer

A)  the gametes fuse, forming an oocyst 
B)  the cells infect the human liver cells 
C)  the cells cause lysing of the human red blood cells 
D)  the oocyst undergoes meiosis 
A)  the gametes fuse, forming an oocyst 
B)  the cells infect the human liver cells 
C)  the cells cause lysing of the human red blood cells 
D)  the oocyst undergoes meiosis

Question 12

Which of the following protists have chloroplasts (or structures since evolved from chloroplasts) thought to be derived from ancestral green algae?

Accepted Answer

A)  stramenopiles 
B)  apicomplexans 
C)  dinoflagellates 
D)  chlorarachniophytes 
A)  stramenopiles 
B)  apicomplexans 
C)  dinoflagellates 
D)  chlorarachniophytes

Question 13

Many chlorophytes are unicellular, but others are larger and more complex. What does this indicate regarding the evolutionary history of chlorophytes?

Accepted Answer

A)  the chlorophyte group is not monophyletic 
B)  the chlorophyte group is monophyletic 
C)  the chlorophyte group is the protist group most closely related to plants 
D)  the chlorophyte group contained extensive genetic variability 
A)  the chlorophyte group is not monophyletic 
B)  the chlorophyte group is monophyletic 
C)  the chlorophyte group is the protist group most closely related to plants 
D)  the chlorophyte group contained extensive genetic variability

Question 14

Which of the following statements correctly compares prokaryotic and eukaryotic flagella?

Accepted Answer

A)  They have the same evolutionary origin. 
B)  They have different structures. 
C)  They require different sources of energy. 
D)  They contain their own DNA. 
A)  They have the same evolutionary origin. 
B)  They have different structures. 
C)  They require different sources of energy. 
D)  They contain their own DNA.

Question 15

Paulinella chromatophora is one of the few cercozoans that is autotrophic, carrying out aerobic photosynthesis with its two elongated "chromatophores." The chromatophores are contained within vesicles of the host cell, and each is derived from a cyanobacterium, though not the same type of cyanobacterium that gave rise to the chloroplasts of algae and plants.
Which of the following results would be most important in determining whether the chromatophore of P. chromatophora is still an endosymbiont, or is an organelle, as the term chromatophore implies?

Accepted Answer

A)  if P. chromatophora is less fit without its chromatophore than with it 
B)  if the chromatophore is less fit without the host cercozoan than with it 
C)  if there is ongoing metabolic cooperation between the chromatophore and the host cercozoan 
D)  if there has been movement of genes from the chromatophore genome to the nuclear genome, such that these genes are no longer present in the chromatophore genome 
A)  if P. chromatophora is less fit without its chromatophore than with it 
B)  if the chromatophore is less fit without the host cercozoan than with it 
C)  if there is ongoing metabolic cooperation between the chromatophore and the host cercozoan 
D)  if there has been movement of genes from the chromatophore genome to the nuclear genome, such that these genes are no longer present in the chromatophore genome

Question 16

Paulinella chromatophora is one of the few cercozoans that is autotrophic, carrying out aerobic photosynthesis with its two elongated "chromatophores." The chromatophores are contained within vesicles of the host cell, and each is derived from a cyanobacterium, though not the same type of cyanobacterium that gave rise to the chloroplasts of algae and plants.
Including the membrane of the surrounding vesicle, which answer identifies the maximum number of phospholipid bilayers present in the chromatophores of P. chromatophora and the bilayer in which the photosystem is most likely located?

Accepted Answer

A)  two; innermost 
B)  two; outermost 
C)  three; innermost 
D)  three; middle 
A)  two; innermost 
B)  two; outermost 
C)  three; innermost 
D)  three; middle

Question 17

The genome of modern chloroplasts is roughly 50% the size of the genome of the cyanobacterium from which it is thought to have been derived. In comparison, the genome of the chromatophore of P. chromatophora is only slightly reduced relative to the size of the genome of the cyanobacterium from which it is thought to have been derived. What is a valid hypothesis that can be drawn from this comparison?

Accepted Answer

A)  Lytic phage infections have targeted the chloroplast genome more often than the P. chromatophora genome. 
B)  The chromatophore of P. chromatophora is the result of an evolutionarily recent endosymbiosis. 
C)  The genome of the chloroplast ancestor contained many more introns that could be lost without harm compared to the chromatophore's genome. 
D)  The genome of the cyanobacteria was smaller than the genome of P. chromatophora. 
A)  Lytic phage infections have targeted the chloroplast genome more often than the P. chromatophora genome. 
B)  The chromatophore of P. chromatophora is the result of an evolutionarily recent endosymbiosis. 
C)  The genome of the chloroplast ancestor contained many more introns that could be lost without harm compared to the chromatophore's genome. 
D)  The genome of the cyanobacteria was smaller than the genome of P. chromatophora.

Question 18

Paulinella chromatophora is a cercozoan that secretes a test, or case around itself consisting of plates made of silica. Which of the following is a rhizarian that would be in competition with P. chromatophora for the silica needed to make these plates, assuming limited quantities of silica in the environment?

Accepted Answer

A)  radiolarians 
B)  foraminiferans 
C)  dinoflagellates 
D)  diatoms 
A)  radiolarians 
B)  foraminiferans 
C)  dinoflagellates 
D)  diatoms

Question 19

Which of the following structures in chlorarachniophytes provides evidence that they evolved through the endosymbiosis of a green alga by a heterotrophic eukaryote?

Accepted Answer

A)  food vacuole 
B)  nucleomorph 
C)  mitosomes 
D)  flagella 
A)  food vacuole 
B)  nucleomorph 
C)  mitosomes 
D)  flagella

Question 20

Which of the following types of protists causes the potentially fatal disease dysentery?

Accepted Answer

A)  Entamoeba histolytica 
B)  Amoeba proteus 
C)  plasmodial slime molds 
D)  Dictyostelium discoideum 
A)  Entamoeba histolytica 
B)  Amoeba proteus 
C)  plasmodial slime molds 
D)  Dictyostelium discoideum

Exam 28: The Origin and Evolution of Eukaryotes

Which of the following groups is matched with a correct anatomical feature?

According to the phylogeny presented in this chapter, which protists are in the same eukaryotic supergroup as plants?

Plastids that are surrounded by more than two membranes are evidence of ________.

Living diatoms contain brownish plastids. If global climate change continues to warm surface waters of Earth's oceans, which of the following is the most likely effect on the animals that build coral reefs?

Which group is correctly paired with its description?

Which of the following characteristics is common among all protists?

A porous test (shell) of calcium carbonate, through which pseudopodia protrude, is characteristic of which of the following groups of organisms?

Many parasitic members of the excavates lack plastids and have highly reduced mitochondria. Which of the following statements explains these observations?

Which of the following results would be most likely if a layer of warm, light water caused by ocean surface warming blocks nutrient upwelling?

When a mosquito infected with Plasmodium first bites a human, what is the first process carried out by the Plasmodium?

Which of the following protists have chloroplasts (or structures since evolved from chloroplasts) thought to be derived from ancestral green algae?

Many chlorophytes are unicellular, but others are larger and more complex. What does this indicate regarding the evolutionary history of chlorophytes?

Which of the following statements correctly compares prokaryotic and eukaryotic flagella?

Which of the following structures in chlorarachniophytes provides evidence that they evolved through the endosymbiosis of a green alga by a heterotrophic eukaryote?

Which of the following types of protists causes the potentially fatal disease dysentery?

Biology and Its Themes

Atoms and Molecules

The Chemistry of Water

Carbon: the Basis of Molecular Diversity

Biological Macromolecules and Lipids

Energy and Life

Cell Structure and Function

Cell Membranes

Cellular Signaling

Cell Respiration

Photosynthetic Processes

Mitosis

Sexual Life Cycles and Meiosis

Mendelian Genetics

Linkage and Chromosomes

Nucleic Acids and Inheritance

Expression of Genes

Control of Gene Expression

Dna Technology

The Evolution of Genomes

How Evolution Works

Phylogenetic Reconstruction

Microevolution

Species and Speciation

Macroevolution

Introduction to Viruses

Prokaryotes

Nonvascular and Seedless Vascular Plants

Seed Plants

Introduction to Fungi

An Introduction to Animal Diversity

Invertebrates

Vertebrates

Plant Structure and Growth

Transport in Vascular Plants

Plant Nutrition

Reproduction of Flowering Plants

Plant Signals and Behavior

The Animal Body

Chemical Signals in Animals

Animal Digestive Systems

Animal Transport Systems

Animal Excretory Systems

Animal Reproductive Systems

Development in Animals

Animal Defenses Against Infection

Electrical Signals in Animals

Neural Regulation in Animals

Sensation and Movement in Animals

An Overview of Ecology

Behavioral Ecology

Populations and Life History Traits

Biodiversity and Communities

Energy Flow and Chemical Cycling in Ecosystems

Conservation and Global Ecology

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