Chapter 18 Review Materials (answers at the end)
Multiple Choice
Write the letter that best answers the question or completes the statement on the line provided.
_____ 1. One reason common names are not useful to biologists is that they
a. are in Latin.
b. can apply to more than one animal.
c. are too long.
d. require the use of a dichotomous key.
_____ 2. At any level of organization, groups that have biological meaning are referred to as
a. cladograms.
c. taxa.
b. binomials.
d. systems.
_____ 3. According to the rules of binomial nomenclature, which of the terms is capitalized?
a. the genus name only
b. the species name only
c. both the genus and species names
d. neither the genus nor species names
_____ 4. Often, the second part of a scientific name is
a. a description of a trait or habitat.
b. the same as for other members of the same genus.
c. capitalized if it derives from a proper name.
d. different in different locations.
_____ 5. When classifying organisms, a monophyletic group includes one
a. species and all its ancestors.
b. ancestor and all its descendants.
c. species and its genus.
d. genus and all its species.
_____ 6. The grouping of organisms based on their common descent is called
a. traditional classification.
b. binomial nomenclature.
c. derived characters.
d. evolutionary classification.
_____ 7. In contrast to Linnaean taxonomy, cladistic analysis considers only which kind of traits, or characters, for
analysis?
a. genetic characters
c. derived characters
b. lost characters
d. physical characters
_____ 8. What does a cladistic analysis show about organisms?
a. the importance of each derived character
b. the relative degrees of relatedness among lineages
c. the general fitness of the organisms analyzed
d. all traits of each organism analyzed
_____ 9. What does the presence of similar DNA sequences in the genes in very dissimilar organisms imply?
a. The genes were produced by different selection pressures.
b. The organisms share a common ancestor.
c. The organisms do not share a common ancestor.
d. The genes became identical through mutation.
_____ 10. What cell structures in eukaryotic cells contain DNA that can be used to determine evolutionary
relationships?
a. nuclei and cytoplasm
c. nuclei and mitochondria
b. nuclei and vacuoles
d. nuclei and microfilaments
_____ 11. Which kingdom contains heterotrophs with cell walls of chitin?
a. Protista
c. Plantae
b. Fungi
d. Animalia
_____ 12. Why is the kingdom Protista not valid under evolutionary classification?
a. Protists are all very similar and easy to confuse.
b. Protista contains groups that share closest common ancestors with other groups, rather than with each
other.
c. Protists are the most numerous organisms on Earth.
d. Protista evolved before any other kingdom, and as such share a most recent common ancestor with each
other, as opposed to any other group.
_____ 13. The domain that contains unicellular organisms that live in extreme environments is
a. Eubacteria.
c. Archaea.
b. Eukarya.
d. Bacteria.
_____ 14. What is thought to be true about the three domains of living things?
a. They diverged from a common ancestor fairly recently.
b. They diverged from a common ancestor before the evolution of the main groups of eukaryotes.
c. They did not have a common ancestor.
d. Domains Bacteria and Archaea evolved after the main groups of eukaryotes.
_____ 15. The two domains composed of only unicellular organisms are
a. Eubacteria and Archaea.
c. Archaea and Bacteria.
b. Eukarya and Bacteria.
d. Archaea and Eukarya.
Modified True/False
Indicate whether the statement is true or false. If false, change the underlined word or phrase to make the statement
true.
16. In the name Ursus maritimus, the word Ursus refers to the species.
17. Modern biologists build classification diagrams called cladograms that reflect lines of evolutionary
descent.
Completion
Complete each statement on the line provided.
18. In systematics, the class Mammalia is grouped with the classes Aves, Reptilia, Amphibia, and all classes of
fishes into the
Chordata.
19. In
evolutionary relationships.
20. The domain
, groups of organisms were formed on the basis of physical traits rather than
contains plants, fungi, protists, and animals—which are all eukaryotes.
21. The domain
is composed of the kingdom Eubacteria.
Short Answer
In complete sentences, write the answers to the questions on the lines provided.
Figure 18–1
22. According to the cladogram in Figure 18–1, what two characteristics do crabs and barnacles share that limpets do
not?
23. In Figure 18–1, what does diagram B, which is based on more recent evidence, show about the classification of
animals shown in diagram A?
24. How can DNA help scientists make the classification of similar organisms such as giant pandas and red pandas
more accurate?
25. Compare and contrast kingdom Fungi and kingdom Plantae in the six kingdom system.
Using Science Skills Use the diagram below to answer the following questions on the lines provided.
Classification of Four Organisms
Corn
Kingdom
Phylum
Class
Order
Family
Genus
Species
Plantae
Anthophyta
Monocotyledones
Commelinales
Poaceae
Zea
Zea mays
Whale Shark
Humpback
Whale
Spider Monkey
Animalia
Chordata
Chondrichthyes
Squaliformes
Rhincodontidae
Rhincodon
Animalia
Chordata
Mammalia
Cetacea
Balaenopteridae
Megaptera
Animalia
Chordata
Mammalia
Primates
Atelidae
Ateles
Rhinacodon typus
Megaptera
novaeangilae
Ateles paniscus
Figure 18–2
26. Interpret Tables Which two organisms listed in Figure 18–2 are most closely related to each other? Explain.
27. Interpret Tables Which level of taxonomic category shown in Figure 18–2 indicates whether an organism is a
mammal or not?
28. Interpret Tables How many different kingdoms are represented by the organisms listed in Figure 18–2? What
are they?
29. Infer If you were adding a column to Figure 18–6 for the protist species Amoeba proteus, would this species
share any taxonomic category with any of the other organisms in the table? Explain your answer.
30. Infer Consider the following statement: “Size and shape are NOT reliable indicators of how closely different
organisms are related.” What information shown in Figure 18–2 supports this statement?
Essay
Write the answer to each question in the space provided.
31. What effect might the common use of the microscope by biologists have had on Linnaeus’s original system of
taxa? Explain.
32. How does cladistic analysis determine the order in which a set of related species evolved?
33. Briefly explain the history of how organisms have been classified—from two kingdoms, to three kingdoms, then
to five, and finally to six kingdoms.
34. How has an increasing knowledge about organisms affected the number of kingdoms now recognized by
biologists? Explain.
35. Why might the three-domain system be a more valid reflection of evolutionary history than the six-kingdom
system?
Chapter 18
Multiple Choice 1. b 2. c 3. a 4. a 5. b 6. d 7. c 8. b 9. b 10. c 11. b 12. b 13. c 14. b 15. c Modified True/False 16. F; genus 17.
T Completion 18. phylum 19. traditional classification; Linnaean classification 20. Eukarya 21. Bacteria Short Answer 22.
segmentation and a molted external skeleton 23. Diagram B indicates that the traditional taxonomic grouping shown in diagram
A classified less closely related groups together based on overall similarities and differences. 24. DNA analysis can supply
further evidence of relatedness. In general, the more derived genetic characters two organisms share, the more closely related
they are. 25. Both fungi and plants are eukaryotes, meaning that their cells have nuclei. Most fungi and plants are multicellular.
All fungi are heterotrophs; all plants are autotrophs. Fungi have cell walls made of chitin; plants have cell walls made of
cellulose. Using Science Skills 26. The humpback whale and the spider monkey are most closely related because they belong to
the same class. 27. the class 28. two; Plantae and Animalia 29. No, because this species belongs to the kingdom Protista. 30.
The whale and the shark look most alike, yet they belong to different classes. The monkey and the whale are more closely
related than any other pair here, yet they differ greatly in size and shape. Essay 31. Common use of the microscope by
biologists likely would have increased the number of species that were identified, and it would have forced biologists to
establish new classification criteria and categories because it would have revealed the widespread existence of microscopic
organ-isms. 32. Cladistic analysis considers derived characters, which are traits passed to the descen-dants of a common
ancestor. If a specific derived character is present in one species but absent in another species, biologists infer that the species
possessing the character evolved second. 33. At first, there were just two groups of organisms—plants and animals (two
kingdoms: Plantae, Animalia). Then, when microorganisms were identified, they got their own kingdom—Protista (three
kingdoms: Plantae, Animalia, and Pro-tista). Later, the fungi were separated from plants and placed into their own kingdom and
prokary-otes were separated from single-celled eukaryotes and placed in their own kingdom, called Monera (five kingdoms:
Plantae, Animalia, Protista, Fungi, and Monera). Today, the monerans have been divided into two kingdoms, Eubacteria and
Archaebacteria (six kingdoms: Plantae, Animalia, Protista, Fungi, Eubacteria, and Archaebacteria). 34. As biologists learned
more about the natural world, they realized that Linnaeus’s two king-doms, Animalia and Plantae, did not adequately represent
the full diversity of life. As a result, the original two kingdoms have today become six kingdoms, with two of those groups used
just for classifying bacteria—unknown in Linnaeus’s time! 35. The three-domain system was based on genomic analysis, which
suggests the evolu-tion of organisms follows three main lines. The six-kingdom system, on the other hand, includes at least one
kingdom (Protista) that is based on general similarities rather than evolutionary relationships.