Chapter 28 , 10th edition
Q1. Why have protists been "mixed in" with plants, animals, and fungi under the hypothesis that groups
eukaryotes into five supergroups?
A) Many protists are more closely related to plants, animals, or fungi than they are to each other.
B) The discovery of very small protists, similar in size to prokaryotes, has made the former classification scheme
obsolete.
C) Recent evidence makes it clear that the former kingdom Protista was paraphyletic.
D) The discovery that protists had organelles made it clear that they should be grouped with other eukaryotes.
None of the listed responses is correct.
The Answer Is : A
Q2. placement of all protists in one kingdom caused dissatisfaction among taxonomists mainly because
__________. (Concept 28.1)
A) various pieces of evidence indicate that the Protista are not polyphyletic
B) various pieces of evidence indicate that the kingdom Protista cannot be monophyletic
C) some protists are autotrophic and others are heterotrophic
D) protist cells are more similar to prokaryotic cells than to eukaryotic cells
E) All of the listed responses are correct.
The Answer Is : B
Q3. Which of the following is one of the main weaknesses of the proposed classification scheme in which all
eukaryotes are divided into four supergroups? ( Concept 28.1)
A) It postulates that photosynthetic protists arose by way of endosymbiosis.
B) It shows all four supergroups diverging simultaneously from a common ancestor.
C) It does not account for "amitochondriate" protists.
D) It does not explain the extra membranes found in some plastids.
E) It does not take into account the importance of endosymbiosis.
The Answer Is : B
Q4. Organisms are classified as Excavata based on __________. (Concept 28.2)
A) the presence of pseudopodia
B) their mode of obtaining energy
C) their lack of true mitochondria
D) morphological studies of the cytoskeleton
E) their origin by secondary endosymbiosis of a red alga
The Answer Is : D
Q5. Which example below is a characteristic shared by diplomonads and parabasalids? (Concept 28.2)
A) Both are adapted to aerobic environments.
B) Both lack plastids.
C) Both have a single flagellum.
D) Both lack mitochondria.
E) Both have two nuclei.
The Answer Is : B
Q6. How do trypanosomes withstand the attack of a host's immune system? (Concept 28.2)
A) The molecular composition of their surface changes continually.
B) They live only in the cerebrospinal fluid, where the immune system can't reach them.
C) They reproduce so fast that they can compensate for the death rate caused by the immune system.
D) They specifically poison helper T cells.
E) All of the listed responses are correct.
The Answer Is : A
Q7. Which of these groups includes photosynthetic unicellular organisms with flagella and contractile vacuoles?
(Concept 28.2)
A) apicomplexans
B) dinoflagellates
C) diatoms
D) ciliates
E) euglenids
The Answer Is : E
Q8. Apicomplexans are currently assigned to the SAR clade because __________. (Concept 28.3)
A) they have life cycles with both sexual and asexual stages
B) they have true roots, stems, and leaves
C) they are parasites
D)the apicoplast, a modified plastid, appears to be of red algal origin
E) Both the first and third responses are correct.
The Answer Is : D
Q9. In many types of protist life cycles, the union of two gametes that results in a diploid zygote is called
__________. (Concept 28.3)
A) endosymbiosis
B) alternation of generations
C) mixotrophy
D) syngamy
E) blooming
The Answer Is : D
Q10. What do a carnivorous dinoflagellate, a parasitic apicomplexan, and a ciliate have in common?
(Concept 28.3)
A) All three form colonies of cells.
B) All three are parasitic on other species of organisms.
C) All three are photosynthetic.
D) All three have sacs known as alveoli just beneath their plasma membranes.
E) All three are heterotrophic and autotrophic.
The Answer Is : D
Q11. Which organisms are capable of producing a "red tide"? (Concept 28.3)
A) euglenids
B) dinoflagellates
C) diatoms
D) radiolarians
E) None of the listed responses is correct.
The Answer Is : B
Q12. Which of these groups includes species that produce a substance that is toxic to humans? (Concept 28.3)
A) apicomplexans
B) euglenids
C) dinoflagellates
D) diatoms
E) ciliates
The Answer Is : C
Q13. Which of these groups includes parasitic unicellular organisms with a complex of organelles specialized for
penetrating host cells and tissues? (Concept 28.3)
A) ciliates
B) euglenoids
C) diatoms
D) apicomplexans
E) dinoflagellates
The Answer Is : D
Q14. Which of these groups is characterized by cells that have more than one nucleus? (Concept 28.3)
A) apicomplexans
B) diatoms
C) ciliates
D) euglenids
E) dinoflagellates
The Answer Is : C
Q15. How do ciliates generate genetic variation? (Concept 28.3)
A) binary fission
B) alternation of generations
C) conjugation
C) asexual reproduction
D) None of the listed responses is correct.
The Answer Is : C
Q16. Which of these groups includes unicellular organisms that, due to the structure of their cell walls, can
withstand pressures equal to the pressure under each leg of a table supporting an elephant? (Concept 28.3)
A) ciliates
B) diatoms
C) dinoflagellates
D) euglenids
E) apicomplexans
The Answer Is : B
Q17. Which characteristic is/are shared by most diatoms, golden algae, and brown algae at least at some stage
of their life cycles? (Concept 28.3)
A) All are autotrophs.
B) All are stramenopiles.
C) They all have flagella with numerous fine, hairlike projections.
D) All of the listed responses are correct.
E) None of the listed responses is correct.
The Answer Is : D
Q18. What is the purpose of the "floats" in some brown algae? (eText Concept 28.3)
A) absorbing iodine and carbon dioxide from seawater
B) anchoring the seaweed
C) protecting the seaweed from drying out
D) protecting seaweed from crashing waves
E) facilitating photosynthesis
The Answer Is : E
Q19. Which of the following organisms is commercially harvested to extract algin from their cell walls?
(Concept 28.3)
A) dinoflagellates
B) brown algae
C) marine green algae, such as Ulva
D) diatoms
E) golden algae
The Answer Is : B
Q20. What role do diatoms play in the global carbon balance affecting global warming? (Concept 28.3)
A) Diatoms release large amounts of carbon dioxide, a greenhouse gas, into the atmosphere.
B) During a bloom, diatom populations may increase rapidly. If many diatoms die and sink to the bottom without
C) being eaten, they effectively pump carbon dioxide out of the atmosphere. Diatomaceous earth can be used to
filter carbon dioxide from the atmosphere.
D) During a bloom, diatom populations increase rapidly, providing many more photosynthetic organisms to the
plankton population.
E)Diatoms release large amounts of methane, a greenhouse gas, into the atmosphere.
The Answer Is : D
Q21. On some areas of the seafloor, one could observe an "ooze" that is hundreds of meters thick. What
creates this ooze? (Concept 28.3)
A) the gel-forming polysaccharides secreted by brown and red algae
B) the tests of dead diatoms
C) colonies of plasmodial slime molds
D) the tests of dead radiolarians
E) the decaying porous shells of forams
The Answer Is : D
Q22. Many species of red algae are adapted to deeper water due to the fact that _________. (Concept 28.4)
A) their photosynthetic pigments efficiently absorb blue and green light
B) their cell walls are adapted to withstand bright light
C) they grow long stalks with floats on the ends to hold the blades near the surface
D) their red pigments readily absorb red light
E) All of the listed responses are correct.
The Answer Is : A
Q23. Which of the following groups of algae is/are most closely related to land plants? (eText Concept 28.4)
A) brown algae
B) red algae
C) golden algae
D) green algae
E) All of the listed responses are correct.
The Answer Is : D
Q24. Plastids that are surrounded by more than two membranes are evidence of
A) origin of the plastids from archaea.
B) fusion of plastids.
C) budding of the plastids from the nuclear envelope.
D) evolution from mitochondria.
E) secondary endosymbiosis.
The Answer Is : E
Q25. Biologists think that endosymbiosis gave rise to mitochondria before plastids partly because
A) the products of photosynthesis could not be metabolized without mitochondrial enzymes.
B) mitochondrial DNA is less similar to prokaryotic DNA than is plastid DNA.
C) without mitochondrial CO2 production, photosynthesis could not occur.
D) all eukaryotes have mitochondria (or their remnants), whereas many eukaryotes do not have plastids.
The Answer Is : D
Q26. Which group is incorrectly paired with its description?
A) apicomplexans-parasites with intricate life cycles
B) diplomonads-protists with modified mitochondria
C) diatoms-important producers in aquatic communities
D) red algae-acquired plastids by secondary endosymbiosis
The Answer Is : D
Q27. Which protists are in the same eukaryotic supergroup as land plants?
A) green algae
B) dinoflagellates
C) red algae
D) brown algae
E) both a and c
The Answer Is : E
Q28. In life cycles with an alternation of generations, multicellular haploid forms alternate with
A) multicellular diploid forms.
B) multicellular polyploid forms.
C) unicellular diploid forms.
D) unicellular haploid forms.
E) multicellular haploid forms.
The Answer Is : A
Q29. Based on the phylogenetic tree in Figure 28.2, which of the following statements is correct?
A) The most basal (first to diverge) eukaryotic supergroup cannot be determined.
B) The most recent common ancestor of Excavata is older than that of Chromalveolata.
C) The most recent common ancestor of Chromalveolata is older than that of Rhizaria.
D) The most recent common ancestor of red algae and land plants is older than that of nucleariids and fungi.
E) Excavata is the most basal eukaryotic supergroup.
The Answer Is : A