Question 1

Which of the following is NOT a producer?

Accepted Answer

A)  green algae 
B)  dinoflagellate 
C)  apicomplexan 
D)  diatom 
E)  euglenid 
A)  green algae 
B)  dinoflagellate 
C)  apicomplexan 
D)  diatom 
E)  euglenid C

Question 2

In the process of alternation of generations, the ________.

Accepted Answer

A)  sporophyte is haploid and produces gametes 
B)  sporophyte is diploid and produces spores 
C)  gametophyte is haploid and produces spores 
D)  gametophyte is diploid and produces gametes 
E)  spores unite to form a zygote 
A)  sporophyte is haploid and produces gametes 
B)  sporophyte is diploid and produces spores 
C)  gametophyte is haploid and produces spores 
D)  gametophyte is diploid and produces gametes 
E)  spores unite to form a zygote B

Question 3

Which major eukaryotic lineages form the Bikonta, a monophyletic group characterized by two flagella as a synapomorphy?

Accepted Answer

A)  Rhizaria, Plantae, Amoebozoa, Opisthokonta, Excavata 
B)  Alveolata, Stramenopila, Rhizaria, Plantae, Excavata 
C)  Rhizaria, Plantae, Excavata 
D)  Amoebozoa, Opisthokonta 
E)  Alveolata, Stramenopila 
A)  Rhizaria, Plantae, Amoebozoa, Opisthokonta, Excavata 
B)  Alveolata, Stramenopila, Rhizaria, Plantae, Excavata 
C)  Rhizaria, Plantae, Excavata 
D)  Amoebozoa, Opisthokonta 
E)  Alveolata, Stramenopila B

Question 4

Which of the following protist lineages is appropriately paired with its supportive and/or protective structure?

Accepted Answer

A)  Diatoms have an intricate, chalky, chambered calcium carbonate shell. 
B)  Parabasalids have an internal support rod, made of cross-linked microtubules, that runs the length of the cell. 
C)  Alveolates have tough plates in the cell wall that are made up of cellulose. 
D)  Euglenoids cover themselves with tiny pebbles. 
E)  Dinoflagellates are surrounded by a glass-like, silicon dioxide cell wall. 
A)  Diatoms have an intricate, chalky, chambered calcium carbonate shell. 
B)  Parabasalids have an internal support rod, made of cross-linked microtubules, that runs the length of the cell. 
C)  Alveolates have tough plates in the cell wall that are made up of cellulose. 
D)  Euglenoids cover themselves with tiny pebbles. 
E)  Dinoflagellates are surrounded by a glass-like, silicon dioxide cell wall.

Question 5

Use the following information to answer the question(s) below.
The mechanism of cell crawling in protist species is not well defined. Pseudopodia extension involves interactions between actin and myosin (the same molecules that are involved in vertebrate muscle contraction). However, prior to the study described below, no one had provided convincing data that actin and myosin were actually involved in cell crawling in protists. Anatomical studies had identified the cytoskeletal protein actin just below the surface of the cell membrane in several species of protist, but physiological studies had failed to show a functional link between actin, myosin, and cell crawling.
In a study by N. Poulsen et al. (Diatom gliding is the result of an actin-myosin motility system, Cell Motility and the Cytoskeleton 44 (1999):23-22), researchers tested whether motility in a particular species of diatom involves interactions between actin and myosin.  
-Refer to the study by Poulsen et al. and the accompanying figure. Latrunculin A is a reversible toxin that disrupts the formation of actin fibers. A culture of a particular species of diatom was treated with this toxin diluted in a buffer, while another culture was treated only with the buffer (no toxin; control). The motility of cells in each culture was assessed by counting the number of cells that were moving during a defined period of time. Which of the following conclusions is reasonable based on the figure?

Accepted Answer

A)  Formation of actin fibers is not necessary for the movement in this species of diatom. 
B)  The buffer alone largely inhibited movement in this species of diatom. 
C)  In this species of diatom, fully formed actin fibers are necessary for movement. 
A)  Formation of actin fibers is not necessary for the movement in this species of diatom. 
B)  The buffer alone largely inhibited movement in this species of diatom. 
C)  In this species of diatom, fully formed actin fibers are necessary for movement.

Question 6

Consider the following points: (a) All excavates live in environments where oxygen availability is low; (b) all excavates lack mitochondria; and (c) all excavates have some mitochondrial genes. Based on this information, which of the following statements is TRUE of the excavate lineage?

Accepted Answer

A)  Their ancestors were eukaryotes that existed prior to the origin of mitochondria. 
B)  Their ancestors had mitochondria, but the mitochondria were lost over time. 
C)  Their ancestors were not able to metabolize glucose. 
D)  Excavates are in the process of acquiring mitochondria through evolutionary adaptation. 
A)  Their ancestors were eukaryotes that existed prior to the origin of mitochondria. 
B)  Their ancestors had mitochondria, but the mitochondria were lost over time. 
C)  Their ancestors were not able to metabolize glucose. 
D)  Excavates are in the process of acquiring mitochondria through evolutionary adaptation.

Question 7

Which of the following statements is consistent with the assertion that protists are paraphyletic?

Accepted Answer

A)  There is no common set of synapomorphies that define a protist 
B)  Protists all share a common set of synapomorphies. 
C)  Protists are all more primitive than land plants and animals. 
D)  Protists do not share a single common ancestor. 
A)  There is no common set of synapomorphies that define a protist 
B)  Protists all share a common set of synapomorphies. 
C)  Protists are all more primitive than land plants and animals. 
D)  Protists do not share a single common ancestor.

Question 8

Which of the following statements best describes the term synapomorphy?

Accepted Answer

A)  a trait that is shared by more than one monophyletic group 
B)  a trait common in a single monophyletic group but not generally found outside of that group 
C)  the state of having several traits in common with different monophyletic groups 
D)  a trait that evolved in several different monophyletic groups simultaneously 
A)  a trait that is shared by more than one monophyletic group 
B)  a trait common in a single monophyletic group but not generally found outside of that group 
C)  the state of having several traits in common with different monophyletic groups 
D)  a trait that evolved in several different monophyletic groups simultaneously

Question 9

-According to the phylogenetic tree in the accompanying figure, G. intestinalis constitutes a ________ group.

Accepted Answer

A)  paraphyletic 
B)  monophyletic 
C)  polyphyletic 
A)  paraphyletic 
B)  monophyletic 
C)  polyphyletic

Question 10

You discover a new species of protist. Which of the following characteristics would provide the strongest evidence for your hypothesis that your species belongs in Euglenida?

Accepted Answer

A)  It is photosynthetic. 
B)  It has a pellicle just under the plasma membrane. 
C)  It reproduces asexually. 
D)  It is unicellular. 
E)  It lacks a cell wall. 
A)  It is photosynthetic. 
B)  It has a pellicle just under the plasma membrane. 
C)  It reproduces asexually. 
D)  It is unicellular. 
E)  It lacks a cell wall.

Question 11

All protists ________.

Accepted Answer

A)  contain a nucleus 
B)  are smaller than animal cells 
C)  are unicellular 
D)  have a cell wall 
E)  are photosynthetic 
A)  contain a nucleus 
B)  are smaller than animal cells 
C)  are unicellular 
D)  have a cell wall 
E)  are photosynthetic

Question 12

Use the following information to answer the question below.
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 gather 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.
A P) bursaria cell that has lost its zoochlorellae is said to be aposymbiotic. It might be able to replenish its contingent of zoochlorellae by ingesting them without subsequently digesting them. Which of the following situations would be most favorable to the reestablishment of resident zoochlorellae, assuming compatible Chlorella are present in P. bursaria's habitat?

Accepted Answer

A)  abundant light, no bacterial prey 
B)  abundant light, abundant bacterial prey 
C)  no light, no bacterial prey 
D)  no light, abundant bacterial prey 
A)  abundant light, no bacterial prey 
B)  abundant light, abundant bacterial prey 
C)  no light, no bacterial prey 
D)  no light, abundant bacterial prey

Question 13

Which of the following was derived from an ancestral cyanobacterium?

Accepted Answer

A)  chloroplast 
B)  mitochondrion 
C)  flagella 
D)  mitosome 
A)  chloroplast 
B)  mitochondrion 
C)  flagella 
D)  mitosome

Question 14

Alternation of generations occurs in some protists. Which of the following represents the correct sequence of events for this mode of reproduction?

Accepted Answer

A)  gametophyte → gamete → fusion → sporophyte → spore → gametophyte 
B)  sporophyte → spore fusion → gametophyte → gamete → sporophyte 
C)  gametophyte → fusion → sporophyte → spore → gamete → gametophyte 
D)  gamete → fusion → gametophyte →spore → sporophyte → gamete 
A)  gametophyte → gamete → fusion → sporophyte → spore → gametophyte 
B)  sporophyte → spore fusion → gametophyte → gamete → sporophyte 
C)  gametophyte → fusion → sporophyte → spore → gamete → gametophyte 
D)  gamete → fusion → gametophyte →spore → sporophyte → gamete

Question 15

Assume that some members of an aquatic species of motile, photosynthetic protists evolve to become parasitic to fish. They gain the ability to live in the fish gut, absorbing nutrients as the fish digests food. Over time, which of the following phenotypic changes would you expect to observe in this population of protists?

Accepted Answer

A)  loss of motility 
B)  loss of chloroplasts 
C)  gain of a rigid cell wall 
D)  gain of meiosis 
E)  No changes would be expected. 
A)  loss of motility 
B)  loss of chloroplasts 
C)  gain of a rigid cell wall 
D)  gain of meiosis 
E)  No changes would be expected.

Question 16

Use the following information to answer the question(s) below.
The mechanism of cell crawling in protist species is not well defined. Pseudopodia extension involves interactions between actin and myosin (the same molecules that are involved in vertebrate muscle contraction). However, prior to the study described below, no one had provided convincing data that actin and myosin were actually involved in cell crawling in protists. Anatomical studies had identified the cytoskeletal protein actin just below the surface of the cell membrane in several species of protist, but physiological studies had failed to show a functional link between actin, myosin, and cell crawling.
In a study by N. Poulsen et al. (Diatom gliding is the result of an actin-myosin motility system, Cell Motility and the Cytoskeleton 44 (1999):23-22), researchers tested whether motility in a particular species of diatom involves interactions between actin and myosin.  
-Refer to the study by Poulsen et al. and the accompanying figure. Cultures of a species of diatom were treated with BDM, a reversible inhibitor of myosin function. Which of the following predictions is consistent with the hypothesis that an actin-myosin interaction is necessary for motility?

Accepted Answer

A)  BDM will significantly decrease motility of the cells in culture. 
B)  BDM will not significantly alter motility of the cells in culture. 
C)  BDM will significantly increase motility of the cells in culture. 
A)  BDM will significantly decrease motility of the cells in culture. 
B)  BDM will not significantly alter motility of the cells in culture. 
C)  BDM will significantly increase motility of the cells in culture.

Question 17

You are given an unknown organism to identify. It is unicellular and heterotrophic. It is motile, using many short extensions of the cytoplasm. It has well-developed organelles and two nuclei, one large and one small. This organism is most likely to be a ________.

Accepted Answer

A)  foraminiferan 
B)  diatom 
C)  ciliate 
D)  dinoflagellate 
E)  slime mold 
A)  foraminiferan 
B)  diatom 
C)  ciliate 
D)  dinoflagellate 
E)  slime mold

Question 18

The microsporidian Brachiola gambiae parasitizes the mosquito Anopheles gambiae. Adult female mosquitoes must take blood meals for their eggs to develop, and it is while they take blood that they transmit malarial parasites to humans. Male mosquitoes drink flower nectar. If humans are to safely and effectively use Brachiola gambiae as a biological control to reduce human deaths from malaria, then how many of the following statements should be TRUE?
1) Brachiola should kill the mosquitoes before the malarial parasite they carry reaches maturity.
2) The microsporidian should not be harmful to other insects.
3) Microsporidians should infect mosquito larvae, rather than mosquito adults.
4) The subsequent decline in anopheline mosquitoes should not significantly disrupt human food resources or other food webs.
5) Brachiola must be harmful to male mosquitoes but not to female mosquitoes.

Accepted Answer

A)  2 and 5 
B)  1, 2, 3, and 4 
C)  1, 2, and 4 
D)  2, 3, 5 
E)  3 and 4 
A)  2 and 5 
B)  1, 2, 3, and 4 
C)  1, 2, and 4 
D)  2, 3, 5 
E)  3 and 4

Question 19

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

Accepted Answer

A)  from infoldings of the plasma membrane, coupled with mutations of genes for proteins in energy-transfer reactions 
B)  from engulfed, originally free-living proteobacteria 
C)  by secondary endosymbiosis 
D)  from the nuclear envelope folding outward and forming mitochondrial membranes 
A)  from infoldings of the plasma membrane, coupled with mutations of genes for proteins in energy-transfer reactions 
B)  from engulfed, originally free-living proteobacteria 
C)  by secondary endosymbiosis 
D)  from the nuclear envelope folding outward and forming mitochondrial membranes

Question 20

Dinoflagellates ________.

Accepted Answer

A)  have a glass-like cell wall 
B)  are all autotrophic 
C)  have walls that are usually composed of cellulose plates 
D)  have a feeding groove 
E)  include species that cause malaria 
A)  have a glass-like cell wall 
B)  are all autotrophic 
C)  have walls that are usually composed of cellulose plates 
D)  have a feeding groove 
E)  include species that cause malaria

Exam 27: Protists

Which of the following is NOT a producer?

In the process of alternation of generations, the ________.

Which major eukaryotic lineages form the Bikonta, a monophyletic group characterized by two flagella as a synapomorphy?

Which of the following protist lineages is appropriately paired with its supportive and/or protective structure?

Consider the following points: (a) All excavates live in environments where oxygen availability is low; (b) all excavates lack mitochondria; and (c) all excavates have some mitochondrial genes. Based on this information, which of the following statements is TRUE of the excavate lineage?

Which of the following statements is consistent with the assertion that protists are paraphyletic?

Which of the following statements best describes the term synapomorphy?

-According to the phylogenetic tree in the accompanying figure, G. intestinalis constitutes a ________ group.

You discover a new species of protist. Which of the following characteristics would provide the strongest evidence for your hypothesis that your species belongs in Euglenida?

All protists ________.

Which of the following was derived from an ancestral cyanobacterium?

Alternation of generations occurs in some protists. Which of the following represents the correct sequence of events for this mode of reproduction?

You are given an unknown organism to identify. It is unicellular and heterotrophic. It is motile, using many short extensions of the cytoplasm. It has well-developed organelles and two nuclei, one large and one small. This organism is most likely to be a ________.

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

Dinoflagellates ________.

Biology and the Tree of Life

Water and Carbon: the Chemical Basis of Life

Protein Structure and Function

Nucleic Acids and the Rna World

An Introduction to Carbohydrates

Ecosystems and Global Ecology

Lipids, Membranes, and the First Cells

Inside the Cell

Energy and Enzymes: an Introduction to Metabolism

Cellular Respiration and Fermentation

Photosynthesis

Cellcell Interactions

The Cell Cycle

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription, Rna Processing, and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

The Molecular Revolution: Biotechnology and Beyond

Genes, Development, and Evolution

Evolution by Natural Selection

Evolutionary Processes

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Green Algae and Land Plants

Fungi

An Introduction to Animals

Protostome Animals

Deuterostome Animals

Viruses

Plant Form and Function

Water and Sugar Transport in Plants

Plant Nutrition

Plant Sensory Systems, Signals, and Responses

Plant Reproduction and Development

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Animal Nervous Systems

Animal Sensory Systems

Animal Movement

Chemical Signals in Animals

Animal Reproduction and Development

The Immune System in Animals

An Introduction to Ecology

Behavioral Ecology

Population Ecology

Community Ecology

Biodiversity and Conservation Biology

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