Biology

Mary Ann Clark, Jung Choi, Matthew Douglas

Chapter 23

Protists - all with Video Answers

Educators

Chapter Questions

Problem 1

What evidence is there that mitochondria were incorporated into the ancestral eukaryotic cell before chloroplasts?

Joanna Quigley

Joanna Quigley

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Problem 2

Which of the following statements about Paramecium sexual reproduction is false?
a. The macronuclei are derived from micronuclei.
b. Both mitosis and meiosis occur during sexual reproduction.
c. The conjugate pair swaps macronuclei.
d. Each parent produces four daughter cells.

Joanna Quigley

Numerade Educator

Problem 3

Which of the following statements about the Laminaria life cycle is false?
a. $1 n$ zoospores form in the sporangia.
b. The sporophyte is the $2 n$ plant.
c. The gametophyte is diploid.
d. Both the gametophyte and sporophyte stages are multicellular.

Joanna Quigley

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Problem 4

What event is thought to have contributed to the evolution of eukaryotes?
a. global warming
b. glaciation
c. volcanic activity
d. oxygenation of the atmosphere

Joanna Quigley

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Problem 5

Which characteristic is shared by prokaryotes and eukaryotes?
a. cytoskeleton
b. nuclear envelope
c. DNA-based genome
d. mitochondria

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Problem 6

Mitochondria most likely evolved by _____________________ .
a. a photosynthetic cyanobacterium b. cytoskeletal elements
D. cytoskent c. endosymbiosis d. membrane proliferation

Joanna Quigley

Numerade Educator

Problem 7

Which of these protists is believed to have evolved following a secondary endosymbiosis?
a. green algae
b. cyanobacteria
c. red algae
d. chlorarachniophytes

Joanna Quigley

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Problem 8

In $2016,$ scientists published the genome of Monocercomonoides, and demonstrated that this organism has no detectable mitochondrial genes. However, its genome was arranged in linear chromosomes wrapped around histones which are contained within the nucleus. Monocercomonoides is therefore a(n)
a. Bacteria
b. Archea
c. Eukaryote
d.Endosymbiont

Joanna Quigley

Numerade Educator

Problem 9

Which of the following observations about a bacterium would distinguish it from the last eukaryotic common ancestor?
a. A double-stranded DNA genome
b. Lack of a membrane-bound structure surrounding the genome
c. Fatty acids in the lipid bilayer of the plasma membrane
d. Enclosed by a cell wall

Joanna Quigley

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Problem 10

Protists that have a pellicle are surrounded by ________________________ .
a. silica dioxide
b. calcium carbonate
c. carbohydrates
d. proteins

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Problem 11

Protists with the capabilities to perform photosynthesis and to absorb nutrients from dead organisms are called __________________ .
a. photoautotrophs
b. mixotrophs
c. saprobes
d. heterotrophs

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Problem 12

Which of these locomotor organs would likely be the shortest?
a. a flagellum
b. a cilium
c. an extended pseudopod
d. a pellicle

Joanna Quigley

Numerade Educator

Problem 13

Alternation of generations describes which of the following?
a. The haploid form can be multicellular; the diploid form is unicellular.
b. The haploid form is unicellular; the diploid form can be multicellular.
c. Both the haploid and diploid forms can be multicellular.
d. Neither the haploid nor the diploid forms can be multicellular.

Dennis Howard

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Problem 14

The amoeba $E$. histolytica is a pathogen that forms liver abscesses in infected individuals. Its metabolic classification is most likely ___________.
a. Anaerobic heterotroph
b. Mixotroph
c. Aerobic phototroph
d. Phagocytic autotroph

Joanna Quigley

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Problem 15

Which protist group exhibits mitochondrial remnants with reduced functionality?
a. slime molds
b. diatoms
c. parabasalids
d. dinoflagellates

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Problem 16

Conjugation between two Paramecia produces ______________ total daughter cells.
a. 2
b. 4
c. 8
"d. 16

Joanna Quigley

Numerade Educator

Problem 17

What is the function of the raphe in diatoms?
a. locomotion
b. defense
c. capturing food
d. photosynthesis

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Problem 18

What genus of protists appears to contradict the statement that unicellularity restricts cell size?
a. Dictyostelium
b. Ulva
c. Plasmodium
d. Caulerpa

Joanna Quigley

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Problem 19

A marine biologist analyzing water samples notices a protist with a calcium carbonate shell that moves by pseudopodia extension. The protist is likely to be closely related to which species?
a. Fuligo septica (Dog Vomit slime mold)
b. Circogonia icosahedra (Radiolarian)
c. Euglena viridis
d. Ammonia tepida

Joanna Quigley

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Problem 20

An example of carbon fixation is __________________ .
a. photosynthesis
b. decomposition
c. phagocytosis
d. parasitism

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Problem 21

Which parasitic protist evades the host immune system by altering its surface proteins with each generation?
a. Paramecium caudatum
b. Trypanosoma brucei
c. Plasmodium falciparum
d. Phytophthora infestans

Joanna Quigley

Numerade Educator

Problem 22

Which of the following is not a way that protists contribute to the food web?
a. They fix carbon into organic molecules.
b. They occupy the apex producer niche.
c. They enter symbiotic relationships with animals.
d. They recycle nutrients back into the carbon and nitrogen cycles.

Joanna Quigley

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Problem 23

Describe the hypothesized steps in the origin of eukaryotic cells.

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Problem 24

Some aspects of eukaryotes are more similar to Archaea, while other aspects of eukaryotic cell composition appear more closely related to Bacteria. Explain how endosymbiosis could resolve this paradox.

Jennifer Stoner

Jennifer Stoner

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Problem 25

Explain in your own words why sexual reproduction can be useful if a protist's environment changes.

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Problem 26

Giardia lamblia is a cyst-forming protist parasite that causes diarrhea if ingested. Given this information, against what type(s) of environments might G. lamblia cysts be particularly resistant?

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Problem 27

Explain how the definition of protists ensures that the kingdom Protista includes a wide diversity of cellular structures. Provide an example of two different structures that perform the same function for their respective protist.

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Problem 28

The chlorophyte (green algae) genera Ulva and Caulerpa both have macroscopic leaf-like and stem like structures, but only Ulva species are considered truly multicellular. Explain why.

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Problem 29

Why might a light-sensing eyespot be ineffective for an obligate saprobe? Suggest an alternative organ for a saprobic protist.

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Problem 30

Opisthokonta includes animals and fungi, as well as protists. Describe the key feature of this phylum, and an example of how an organism in each kingdom uses this feature.

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Problem 31

Describe two ways in which paramecium differs from the projected traits of the last eukaryotic common ancestor.

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Problem 32

How does killing Anopheles mosquitoes affect the Plasmodium protists?

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Problem 33

Without treatment, why does African sleeping sickness invariably lead to death?

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Problem 34

Describe how increasing stress to the ocean would affect a food chain containing zooxanthellae, corals, parrotfish, and sharks.

Joanna Quigley

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