Question 1

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 2

In examining a multicellular protist,you notice that it uses pseudopods to engulf its food,that it reproduces asexually by mitosis,and that it has multiple nuclei.These data allow you to infer that the species belongs to which of the following protist groups?

Accepted Answer

A) Euglenida 
B) Diatoms 
C) Foraminifera 
D) Diplomonadida 
E) Parabasalida 
A) Euglenida 
B) Diatoms 
C) Foraminifera 
D) Diplomonadida 
E) Parabasalida

Question 3

Which of the following monophyletic eukaryotic clades includes photosynthetic species with double-membraned chloroplasts?

Accepted Answer

A) Bikonta 
B) Unikonta 
C) Opisthokonta 
D) Chromalveolata 
A) Bikonta 
B) Unikonta 
C) Opisthokonta 
D) Chromalveolata

Question 4

You discover a new eukaryotic species.It is non-photosynthetic,unicellular,and its motile cells contain a single flagellum.To which group of eukaryotes might this organism belong?

Accepted Answer

A) Amoebozoa 
B) Excavata 
C) Rhizaria 
D) Alveolata 
A) Amoebozoa 
B) Excavata 
C) Rhizaria 
D) Alveolata

Question 5

Which of the following is most likely to lead to PSP (paralytic shellfish poisoning)?

Accepted Answer

A) dinoflagellates 
B) Giardia 
C) Plasmodium 
D) Toxoplasma 
E) diatoms 
A) dinoflagellates 
B) Giardia 
C) Plasmodium 
D) Toxoplasma 
E) diatoms

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

Encouraging the growth (via nutrient fertilization)of photosynthetic protists in marine environments may help reduce global warming.Why?

Accepted Answer

A) because photosynthetic protists form the base of many marine food chains 
B) because photosynthetic protists fix atmospheric carbon dioxide,decreasing atmospheric CO₂ levels 
C) because the increased oxygen consumption by large populations of photosynthetic protists will promote land plants to speed up photosynthesis,thus removing CO₂ from the atmosphere 
D) because photosynthetic protists would release a lot of oxygen,and fertilizing them would increase levels of oxygen in the atmosphere 
A) because photosynthetic protists form the base of many marine food chains 
B) because photosynthetic protists fix atmospheric carbon dioxide,decreasing atmospheric CO₂ levels 
C) because the increased oxygen consumption by large populations of photosynthetic protists will promote land plants to speed up photosynthesis,thus removing CO₂ from the atmosphere 
D) because photosynthetic protists would release a lot of oxygen,and fertilizing them would increase levels of oxygen in the atmosphere

Question 8

When a mosquito infected with Plasmodium first bites a human _____.

Accepted Answer

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

Question 9

Imagine there are 25 different species of protists living in a tide pool.Some of these species reproduce both sexually and asexually,and some of them can reproduce only asexually.The pool gradually becomes infested with disease-causing viruses and bacteria.Which species are more likely to thrive in the changing environment?

Accepted Answer

A) the sexually reproducing species 
B) the asexually reproducing species 
C) Sexually and asexually reproducing species are equally likely to thrive. 
D) cannot tell from this information - survival will depend on a variety of other factors 
A) the sexually reproducing species 
B) the asexually reproducing species 
C) Sexually and asexually reproducing species are equally likely to thrive. 
D) cannot tell from this information - survival will depend on a variety of other factors

Question 10

Which of the following observations about flagella is true and is consistent with the scientific conclusion that the flagella from protists and bacteria evolved independently?

Accepted Answer

A) The flagella of both protists and bacteria are made of the same protein,but the configuration is different. 
B) The mechanics of movement and protein structure are the same in these flagella,but there are significant genetic differences. 
C) Although the mechanism of movement in both flagella is the same,the protein that accomplishes the movement is different. 
D) The protein structure and the mechanism of movement in protist flagella are different from those of bacteria flagella. 
A) The flagella of both protists and bacteria are made of the same protein,but the configuration is different. 
B) The mechanics of movement and protein structure are the same in these flagella,but there are significant genetic differences. 
C) Although the mechanism of movement in both flagella is the same,the protein that accomplishes the movement is different. 
D) The protein structure and the mechanism of movement in protist flagella are different from those of bacteria flagella.

Question 11

Figure 29.3
Use the following information when answering the corresponding question(s).
The mechanism of cell crawling in protist species is not well defined.The textbook states that pseudopodia extension involves interactions between actin and myosin (the same molecules that are involved in mammalian 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 Figure 29.3.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 conclusion statements is reasonable based on the above 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 12

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 13

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 contains the carbohydrate paramylon. 
C) It reproduces asexually. 
D) It is unicellular. 
E) It lacks a cell wall. 
A) It is photosynthetic. 
B) It contains the carbohydrate paramylon. 
C) It reproduces asexually. 
D) It is unicellular. 
E) It lacks a cell wall.

Question 14

Plankton is comprised of photosynthetic protists and bacteria.What is the primary importance of plankton to humans?

Accepted Answer

A) They are food for many marine organisms that humans eat. 
B) They release a lot of carbon dioxide into the atmosphere. 
C) They contribute to the formation of anaerobic dead zones in the oceans. 
D) They form the basic building blocks in the formation of petroleum (oil). 
A) They are food for many marine organisms that humans eat. 
B) They release a lot of carbon dioxide into the atmosphere. 
C) They contribute to the formation of anaerobic dead zones in the oceans. 
D) They form the basic building blocks in the formation of petroleum (oil).

Exam 29: Protists

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

In examining a multicellular protist,you notice that it uses pseudopods to engulf its food,that it reproduces asexually by mitosis,and that it has multiple nuclei.These data allow you to infer that the species belongs to which of the following protist groups?

Which of the following monophyletic eukaryotic clades includes photosynthetic species with double-membraned chloroplasts?

You discover a new eukaryotic species.It is non-photosynthetic,unicellular,and its motile cells contain a single flagellum.To which group of eukaryotes might this organism belong?

Which of the following is most likely to lead to PSP (paralytic shellfish poisoning)?

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?

Encouraging the growth (via nutrient fertilization)of photosynthetic protists in marine environments may help reduce global warming.Why?

When a mosquito infected with Plasmodium first bites a human _____.

Which of the following observations about flagella is true and is consistent with the scientific conclusion that the flagella from protists and bacteria evolved independently?

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?

Plankton is comprised of photosynthetic protists and bacteria.What is the primary importance of plankton to humans?

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

Lipids, membranes, and the First Cells

Inside the Cell

Cell-Cell Interactions

Cellular Respiration and Fermentation

Photosynthesis

The Cell Cycle

Meiosis

Mendel and the Gene

Dna and the Gene: Synthesis and Repair

How Genes Work

Transcription and Translation

Control of Gene Expression in Bacteria

Control of Gene Expression in Eukaryotes

Analyzing and Engineering Genes

Genomics

Principles of Development

An Introduction to Animal Development

An Introduction to Plant Development

Evolution by Natural Selection

Evolutionary Processes

Speciation

Phylogenies and the History of Life

Bacteria and Archaea

Green 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

Animal Form and Function

Water and Electrolyte Balance in Animals

Animal Nutrition

Gas Exchange and Circulation

Electrical Signals in Animals

Animal Sensory Systems and Movement

Chemical Signals in Animals

Animal Reproduction

The Immune System in Animals

An Introduction to Ecology

Behavioral Ecology

Population Ecology

Community Ecology

Ecosystems

Biodiversity and Conservation Biology

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