Download Skinner Chapter 17

Fall 2000
Lohrengel
Geology 1013 - Earth System Science
Chapter 17 - Study
Instructions:
Read each question carefully before answering. Work at a steady pace, and you should
have ample time to finish.
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1. Approximately 1.5 million species have been identified and named so
far; most of them are insects and plants.
2. It is likely that the first living organisms were bacteria.
3. Procaryotes were the first type of organisms to be able to reproduce
sexually.
4. The Ediacaran animals are fossils of the earliest known
multicellular organisms.
5. The first skeletons, both internal and external, evolved in the
Cambrian Period.
6. The first plants were seedless.
7. The first land animals, amphibians, left the sea in the early
Devonian Period.
8. Even organisms that do not move themselves have reproductive
structures that can migrate into habitats previously occupied by
another population.
9. Provinciality is a measure of the extent to which the Earth system
is divided into subsystems by barriers to the migration of
organisms.
10. The greatest of all mass extinctions in Earth history was the
Cretaceous-Tertiary extinction, in which the dinosaurs died out,
along with many other species.
11. The principle of competitive exclusion says that
a. two species that have the same requirements cannot coexist in the
same habitat.
b. diversity in an ecosystem is defined by the number of species in
the ecosystem.
c. the larger the niches in an ecosystem, the lower the diversity;
the smaller the niches, the greater the diversity.
d. intrinsic factors such as competition for food can limit
population growth in a given species.
12. Mutations
a. are caused by a change in DNA, resulting in a change in inherited
characteristics.
b. can be caused by external environmental agents.
c. can add variability to a species, or even result in a new
species.
d. All of these are true.
13. Genetic drift
a. can change an individual species, but it cannot affect the
overall course of evolution.
b. refers to change in the frequency of a gene in a population as a
result of change.
c. can be caused by selection, mutation, or migration.
d. All of these are true.
14. Which one of the following is not an aspect of species diversity?
a. species richness
b. species evenness
c. species competition
d. species dominance
15. In low latitudes, where climatic conditions are more or less
constant the year round, one might expect ___________ niches and
__________ diversity (which is, in fact, the case both on land and
in the ocean).
a. narrow...low
b. large...high
c. narrow...high
d. large...low
16. Which one of the following is thought to have been the first life
form?
a. bacteria
b. viruses
c. stromatolites
d. None of these
17. Provinciality
a. is high at the present time.
b. correlates positively with biological diversity.
c. is enhanced by the presence of climatic or geographic barriers.
d. All of these are true.
18. Wha t unusual feature was shared by almost all of the Ediacaran
animals?
a. large
b. jelly- like
c. disc-shaped
d. branching structures
19. Aerobic eucaryotes
a. use oxygen for respiration.
b. cannot successfully maintain a complex structure with a nucleus
and organelles.
c. require a large surface-to-volume ratio in order to allow for
rapid diffusion of food in and waste out.
d. All of these are true.
20. Which one of the following does not belong with the o thers?
a. panspermia
b. outer space
c. carbonaceous chondrites
d. black smokers
21. Before about ________ years ago, the Earth's atmosphere was
deficient in oxygen.
a. 1.5 billion
b. 15 billion
c. 15 million
d. 1.5 million
22. For at least two billion years, the only life on Earth was
a. eucaryotic.
b. procaryotic.
c. aerobic.
d. multicellular.
23. The earliest fossils are found in rocks about _________ years old.
a. 60 million
b. 600 million
c. 1.4 billion
d. 3.5 billion
24. A marked increase in global biological diversity occurred
a. in Late Proterozoic time.
b. after the advent of nucleated cells.
c. after sufficient oxygen had accumulated in the atmosphere to
allow respiration.
d. All of these are true.
25. The earliest fossils of complex multicellular organisms are found in
rocks about _________ years old.
a. 60 million
b. 600 million
c. 1.4 billion
d. 3.5 billion
26. Which one of the following does not belong with the others?
a. Phanerozoic
b. Proterozoic
c. Cenozoic
d. Archean
27. Mammals originated in the _________ Period.
a. Holocene
b. Cretaceous
c. Triassic
d. Proterozoic
28. The first animals to make the change from sea to land were
a. arthropods.
b. crossopterygians.
c. chordates.
d. stromatolites.
29. Land plants provide themselves with an internal aquatic environment
through
a. pollination.
b. spores.
c. vascular systems.
d. diffusion.
30. The history of the Earth since the beginning of the Cambrian Period
is divided into three eras. They are the
a. Cambrian, Ordovician, and Silurian.
b. Paleozoic, Mesozoic, and Cenozoic.
c. Proterozoic, Paleozoic, and Cenozoic
d. Archean, Proterozoic, and Paleozoic.
31. The hypothesis that life originated in outer space and was then
dispersed to other parts of the universe, including the Earth, is
called ________________.
32. Species with a wide range of environmental tolerance are called
________________; those with a narrow range of tolerance are called
________________.
33. Where a species lives is its ________________; what it does for a
living is its ________________.
34. Submarine hot springs are called ________________.
35. The most ancient fossils that have been found are approximately
________________ years old.
36. The earliest known animal fossils are called the _______________;
they were found in 600- million-year-old rocks in South Australia.
37. In the Permian-Triassic extinction, about _______________ percent of
all species alive at the time were lost.
38. _________________ is the synthesis of small organic molecules such
as amino acids from gases in the atmosphere or in space.
39. _________________ is the polymerization of small organic molecules
to form biopolymers such as proteins.
40. Layered structures composed of calcium carbonate precipitated by
blue-green algae are called ___________________.
41. Biological diversity involves three different concepts. What are
they?
42. Species diversity encompasses three concepts. What are they? (List
and briefly explain.)
43. What are the three important steps that must have been accomplished
in order for metabolismƒƒand thus lifeƒƒto be possible?
44. What are stromatolites, and what is their significance for the
history of life on the Earth?
45. Why is it improbable that the earliest form of life on Earth was a
bacterium?
46. What is the most widely held hypothesis for the cause of the
Cretaceous-Tertiary extinction?
47. What is the most widely held hypothesis for the cause of the
Permian-Triassic extinction?
48. What are the four requirements that had to be met in order for life
to be able to leave the sea and live on land?
49. What is an ecological niche?
50. Which species are the most likely to be endangered through human
activities? Why are "specialist" species more vulnerable than
"generalist" specie s?
51. What is industrial melanism? Give an example of how it might occur.
52. Describe the organic "soup" hypothesis for the origin of life on the
Earth. What are the main problems with this theory?
53. Summarize the evidence that suggests that the Earth's atmosphere was
oxygen-deficient before about 1.5 billion years ago.
54. What are the limitations of anaerobic cells, compared to aerobic
cells?
55. There are two popular hypotheses for the origin of eucaryotic cells
from procaryotic cells. What are they?
56. Discuss the Ediacara fauna and their significance in terms of our
understanding of early life forms on Earth.
57. What are the main hypotheses offered as explanations for the great
expansion of biological diversity that occurred in the Cambrian
Period?
58. Describe the panspermia theory of the origin of life. What are some
of the attractive points and some of the major problems with this
theory?
_____________________________________________
Fall 2000
Lohrengel
Geology 1013 - Earth System Science
Answer Key: Chapter 17 - Study
1. T
2. F
3. F
4. T
5. T
6. T
7. T
8. T
9. T
10. F
11. A
12. D
13. B
14. C
15. C
16. D
17. D
18. B
19. A
20. D
21. A
22. B
23. D
24. D
25. B
26. C
27. C
28. A
29. C
30. B
31. panspermia
32. generalists...specialists
33. habitat...ecological niche
34. black smokers
35. 3.5 billion
36. Edicara fauna
37. 95
38. Chemosynthesis
39. Biosynthesis
40. stromatolites
41. Biological diversity involves the concepts of (1) genetic diversity,
(2) habitat diversity, and (3) species diversity.
42. Species diversity encompasses the concepts of (1) species richness
(the total number of species), (2) species evenness (the relative
abundance of species), and (3) species dominance (the most abundant
species).
43. (1) Chemosynthesis; (2) biosynthesis; and (2) the development of the
equipment needed for replication.
44. Stromatolites are layered growths that form in warm, shallow seas
when photosynthetic bacteria cause dissolved salts to precipitate.
Fossil stromatolites billions of years old are not the fossils of
actual organisms, but the y provide clear evidence of their presence.
45. Even though bacteria are the simplest known living organisms,
nevertheless they are complexƒƒtoo complex, probably, to have been
the first living organisms.
46. The most widely held hypothesis is that the impact of a large
meteorite and consequent disruption of climate caused a mass
extinction of species.
47. The rearrangement of landmasses into the supercontinent Pangaea, and
the consequent loss of habitats is the most likely cause of this
mass extinction.
48. The requirements are (1) structural support; (2) an internal aquatic
environment; (3) means for exchanging gases with air instead of with
water; (4) a moist environment for the reproductive system.
49. An ecological niche is the set of all environmental conditions under
which a species can persist. It represents an organism's
"profession"ƒƒessentially, what the organism does for a living.
50. Species that are the most likely to become endangered are often
long- lived and large. They tend to have low reproductive rates and
recover slowly from lowered population levels. The biggest also
require the largest territories and the most food per individual.
Specialists speciesƒƒthose adapted to very narrow sets of conditions
and having highly specific habitat and behavior requirementsƒƒare
also especially vulnerable because the diversity of available
habitat is reduced by human activity. Generalist species, especially
those that share food and habitats with people, do better.
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