1. The Miller-Urey experiment demonstrated that—
a. life originated on Earth
b. organic molecules could have originated in the early atmosphere
c. the early genetic material on the planet was DNA
d. the early atmosphere contained large amounts of oxygen
The correct answer is b—
A. Answer a is incorrect. The Miller-Urey experiments focused on organic molecule
evolution.
The correct answer is b—organic molecules could have originated in the early
atmosphere
B. Answer b is correct.
The correct answer is b—
C. Answer c is incorrect. First, the early genetic material on the planet was most
likely RNA. Second, the Miller-Urey experiments did not study the origins of the
genetic material.
The correct answer is b—
D. Answer d is incorrect. Early atmosphere most likely lacked oxygen.
2. Which of the following properties of life would have to be significantly different
for an organism that evolved on a planet located far from its sun?
a. homeostasis
b. reproduction
c. growth
d. sensitivity
The correct answer is c—
A. Answer a is incorrect. Any living organism would need to maintain an internal
environment that was different from its external environment.
The correct answer is c—
B. Answer b is incorrect. In order to be classified as living, an organism must have
the ability to reproduce.
The correct answer is c—growth
C. Answer c is correct. Life on Earth is primarily based on the use of photosynthetic
pathways to establish covalent bonds. On a sunless planet an alternative system
must have evolved to support life.
The correct answer is c—
D. Answer d is incorrect. Living organisms must respond to stimuli, although the
form and response may differ between organisms and locations.
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3. Which of the following represents a limitation of the Linnean system of
classification?
a. The degree of biological diversity may differ significantly between two
evolutionarily different families.
b. Some taxonomic groups are not monophyletic.
c. The ranks used in the Linnean system are not evolutionarily equivalent.
d. All of the above are limitations.
The correct answer is d—
A. Answer a is incorrect. Although this is a limitation of the Linnean system, there
are additional correct answers.
The correct answer is d—
B. Answer b is incorrect. Although this is a limitation of the Linnean system, there
are additional correct answers.
The correct answer is d—
C. Answer c is incorrect. Although this is a limitation of the Linnean system, there
are additional correct answers.
The correct answer is d—All of the above are limitations.
D. Answer d is correct. All of these are limitations of the Linnean system.
4. Which of the following would not belong to the domain Eukarya?
a. Photosynthetic plants
b. Multicellular fungi
c. Thermophile archae
d. Multicellular animals
The correct answer is c—
A. Answer a is incorrect. Plants are eukaryotic organisms, the key characteristic of
the Eukarya.
The correct answer is c—
B. Answer b is incorrect. Fungi are eukaryotic organisms, the key characteristic of
the Eukarya.
The correct answer is c—Thermophile archae
C. Answer c is correct. A thermophilic archae would belong to the domain Archaea.
The correct answer is c—
D. Answer d is incorrect. Animals are eukaryotic organisms, the key characteristic of
the Eukarya
5. Which of the following kingdoms presented the greatest challenge to the
acceptance of a six-kingdom system?
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a.
b.
c.
d.
Plantae
Animalia
Protista
Archaea
The correct answer is c—
A. Answer a is incorrect.
The correct answer is c—
B. Answer b is incorrect.
The correct answer is c—
C. Answer c is correct. The Protista represent a paraphyletic group with distinct
evolutionary relationships.
The correct answer is c—
D. Answer d is incorrect.
6. Which of the following statements is false?
a. Brown and red algae are not closely related phylogenetically.
b. Chloroplasts in brown and red algae are monophyletic.
c. Brown algae gained chloroplasts by engulfing green algae
(endosymbiosis).
d. None of the above statements are false.
The correct answer is d—
A. This statement is true.
The correct answer is d—
B. This statement is true. Although brown and red algae are not monophyletic, their
chloroplasts are.
The correct answer is d—
C. The statement is true. Brown algae likely engulfed red, not green algae.
The correct answer is d—
D. This statement is false since a, b, and c are all true.
7. Which of the following events occurred first in eukaryotic evolution?
a. Endosymbiosis and mitochondria evolution
b. Endosymbiosis and chloroplast evolution
c. Compartmentalization and formation of the nucleus
d. Formation of multicellular organisms
The correct answer is c—
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A. Answer a is incorrect. Refer to Figure 26.9 in the text.
The correct answer is c—
B. Answer b is incorrect. Refer to Figure 26.9 in the text
The correct answer is c—Compartmentalization and formation of the nucleus
C. Answer c is correct. Eukaryotes are defined as cells that possess a nucleus, thus
this must be one of the earliest events.
The correct answer is c—
D. Answer d is incorrect. Not all eukaryotes are multicellular.
8. Biologists include viruses in which of the following kingdoms?
a. Archaea
b. Fungi
c. Bacteria
d. None of the above
The correct answer is d—
A. Answer a is incorrect. Biologists do not consider viruses to be living, thus they are
not included in any kingdom.
The correct answer is d—
B. Answer b is incorrect. Biologists do not consider viruses to be living, thus they
are not included in any kingdom.
The correct answer is d—
C. Answer c is incorrect. Biologists do not consider viruses to be living, thus they are
not included in any kingdom.
The correct answer is d—
D. Answer d is correct. Biologists do not consider viruses to be living, thus they are
not included in any of the kingdoms listed.
9. As a researcher you discover a new species that is eukaryotic, motile, possesses a
cell wall made of chitin, but lacks any evidence of a nervous system. To what
kingdom of life would you assign it?
a. Protista
b. Animalia
c. Fungi
d. Plantae
The correct answer is c—
A. Answer a is incorrect. Refer to Table 26.2 in the text.
The correct answer is c—
B. Answer b is incorrect. Refer to Table 26.2 in the text.
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The correct answer is c—Fungi
C. Answer c is correct. The organism most closely resembles a fungus.
The correct answer is c—
D. Answer d is incorrect. Refer to Table 26.2 in the text.
10. Kingdom Plantae is being replaced by a new kingdom named Viridiplantae based
on evidence obtained from which of the following?
a. Molecular phylogenetics
b. New discovered fossils
c. Biochemical differences
d. All of the above
The correct answer is a—Molecular phylogenetics
A. Answer a is correct. Refer to Figure 26.12
The correct answer is a—
B. Answer b is incorrect. Other evidence has led to a reclassification.
The correct answer is a—
C. Answer c is incorrect. Biochemical evidence alone has not been sufficient to lead
to the reclassification of the Viridiplantae
The correct answer is a—
D. Answer d is incorrect. Answer a is correct.
11. Research in which of the following areas has the greatest potential to increase our
understanding of land plant evolution?
a. Photosynthetic pigments
b. Chloroplast endosymbiosis
c. Horizontal gene transfer
d. Changes in cell wall composition
The correct answer is c—
A. Answer a is incorrect.
The correct answer is c—
B. Answer b is incorrect.
The correct answer is c—Horizontal gene transfer
C. Answer c is correct.
The correct answer is c—
D. Answer d is incorrect.
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12. In animals, the process of _______ is under control of the Hox genes.
a. multicellularity
b. sexual reproduction
c. cellular compartmentalization
d. segmentation
The correct answer is d—
A. Answer a is incorrect. Hox genes do not control multicellularity.
The correct answer is d—
B. Answer b is incorrect. Hox genes do not control sexual reproduction.
The correct answer is d—
C. Answer c is incorrect. Hox genes do not control cellular compartmentalization.
The correct answer is d—segmentation
D. Answer d is correct. Hox genes are responsible for segmentation.
13. Based on ribosomal RNA information, which of the following groups is most
closely related to the Arthropods?
a. Echinoderms
b. Nematodes
c. Mollusks
d. Annelids
The correct answer is b—
A. Answer a is incorrect. Refer to Figure 26.15.
The correct answer is b—Nematodes
B. Answer b is correct. Refer to Figure 26.15.
The correct answer is b—
C. Answer c is incorrect. Refer to Figure 26.15.
The correct answer is b—
D. Answer d is incorrect. Refer to Figure 26.15.
14. The study of the Distal-less Hox gene refuted what morphological evidence of
arthropod evolution?
a. Protostome and deuterostome classification
b. Limb morphology and development
c. Metamorphosis
d. Development of eyes
The correct answer is b—
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A. Answer a is incorrect. Studies of the Distal-less gene did not contribute to this
area.
The correct answer is b—
B. Answer b is correct.
The correct answer is b—
C. Answer c is incorrect. Studies of the Distal-less gene did not contribute to this
area
The correct answer is b—Development of eyes
D. Answer d is incorrect. Studies of the Distal-less gene did not contribute to this
area.
15. The reclassification of whales within the Eutherians is primarily based on which
of the following?
a. Morphological information from fossils
b. Morphological information from hippopotamuses
c. Morphological evidence from carnivores
d. DNA sequence data
The correct answer is d—
A. Answer a is incorrect. Reclassification of whales was not based primarily on this
information.
The correct answer is d—
B. Answer b is incorrect. Reclassification of whales was not based primarily on this
information.
The correct answer is d—
C. Answer c is incorrect. Reclassification of whales was not based primarily on this
information.
The correct answer is d—DNA sequence data
D. Answer d is correct. Reclassification of whales was based primarily on this
information, which in turn led to additional studies of fossils.
Challenge Questions
1. The conditions on Mars, Jupiter’s moon Europa, and Saturn’s moon Titan mimic
those that are believed to have occurred on the early Earth. Yet, these places are
also different from our early planet. For example, both Europa and Titan are
located far from the Sun. Suppose that someday in the future scientists discover
bacteria on these moons that are very similar biochemically to the early bacteria
on Earth. Explain how this information would support the theory of panspermia.
What if the life was biochemically different?
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Answer—If the life is biochemically the same on one of these moons and Earth, then it is
possible that life originated in one place and was moved to the other location by the
action of meteorites and comets. As you have seen with convergent evolution,
panspermia would still not be proven by such a finding. However, if the life was
biochemically different it would suggest that life originated independently on the moons
and Earth.
2. You are part of a research team that has recently discovered evidence of a singlecelled prokaryotic organism on Mars. As you begin your study of the organism,
you wish to use a species from Earth as a comparison. What domain of life should
you obtain your reference species from, and why?
Answer—The most logical choice would be a species from the domain Archae. These
are considered to be the oldest forms of life on our planet, and are known to have evolved
to survive harsh environmental condition.
3. In the past, classification has relied primarily on the evolution of morphological
characteristics. Modern approaches are relying more heavily on molecular
analysis. Why is the molecular approach so important in developing evolutionary
hypotheses?
Answer—Morphology may be influenced by processes such as convergent evolution.
However, DNA acts as a molecular record of a species’ past. Combining what is being
learned from both morphological and molecular data leads to more robust evolutionary
hypotheses.
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