AP Biology
Origins and Diversity of Life on Earth
Reading Guide – Chapter s 31 - 33 - The Evolution of Animals
Chapters 31, 32, and 33 The Animals
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1. What major geological period marks the evolution of animals? How long ago was this event?
2. List and describe the general characteristics of animals.
3. What synapomorphies are shared among all species of animals?
4. What protistans are thought to be the ancestor to animals?
5. List the criteria used to classify animals.
6. Animals can be differentiated into two major groups based on embryonic development: protostomes
or deuterostomes. Explain the differences between each group.
7. What are germ layers? Define diploblastic and triploblastic.
8. Define the types of symmetry.
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AP Biology
Origins and Diversity of Life on Earth
Reading Guide – Chapter s 31 - 33 - The Evolution of Animals
9. What is the advantage of radial symmetry? Of bilateral symmetry?
10. What is cephalization?
11. Define coelom.
12. Distinguish between acoelomate, pseudocoelomate and coelomate. What significant advantages
arise from the coelomate body plan?
13. Illustrate the difference between the tube-within-a-tube vs. sac body plan. What is the significance
of the tube of each body plan in terms of development of the digestive system?
14. What are some of the advantages of the development of muscle tissue?
15. Define segmentation. Which animals are considered to be segmented?
16. Define sessile.
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AP Biology
Origins and Diversity of Life on Earth
Reading Guide – Chapter s 31 - 33 - The Evolution of Animals
17. What is the connection between sessile life style and filter feeding?
18. What adaptations are necessary for sessile organisms?
19. Distinguish between direct development and larval development in animal life cycles. What might
be the advantage of a dimorphic life cycle?
20. Describe methods of dispersal in animal life cycles.
ADVENT OF MULTICELLULARITY – SPONGES
21. What feature distinguishes sponges from other heterotrophic protists?
22. What features make sponges different from the other organisms placed in the animal kingdom?
23. Do sponges have tissues?
24. List the types of cells found in a sponge, and describe their functions.
25. Give the function of:
a. Sponging and spicules
b. Porocytes
c. Choanocytes (collar cells)
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AP Biology
Origins and Diversity of Life on Earth
Reading Guide – Chapter s 31 - 33 - The Evolution of Animals
d. Amoebocytes
26. How can sponges reproduce? Define budding.
27. What is the advantage of asexual reproduction?
TRUE TISSUE LAYERS AND RADIAL SYMMETRY – CNIDARIANS AND CTENOPHORA
28. How many tissue layers are present in these phyla? What are they? Would they be considered
diploblastic or triploblastic?
29. Animals in these phyla exhibit what type of symmetry?
30. Animals that have only two well developed cell layers have a layer of acellular
___________________ between the layers of cells.
31. What common animals are found in phylum Ctenophora?
32. What common animals are found in phylum Cnidaria?
33. Why is the gut of cnidarians called a gastrovascular cavity?
34. Do cnidarians have mesoderm?
35. What is the function of nematocysts?
36. Define dimorphic.
37. What are the two body forms found in cnidarians? Explain how they function in the life cycle of
various types of cnidarians.
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AP Biology
Origins and Diversity of Life on Earth
Reading Guide – Chapter s 31 - 33 - The Evolution of Animals
38. Describe the anatomy of Hydra, pointing out those features that typify cnidarians.
CHAPTER 32 -- ADVENT OF BILATERAL SYMMETRY, PROTOSTOME DEVELOPMENT AND TRIPLOBLASTIC
ANIMALS
All bilaterally symmetrical animals have three germ layers. This provides the possibility of being
acoelomate, pseudocoelomate, or coelomate. In addition, we see either the sac or tube-within-a-tube
body plan. The protostomes are currently divided into two major groups: the lophotrochozoans and the
ecdysozoans, based on a larval developmental stage. We are not going to be concerned with this
distinction. Rather, the major animal Phyla and characteristics you should focus on are given below.
Acoelomates – Platyhelminthes (Flatworms)
39. Platyhelminthes (Common Name:
a. Symmetry:
b. Tissue Layers:
c. Body Cavity:
d. Digestive system:
e. Circulatory structures:
f.
Respiration:
g. Excretory:
h. Nervous system:
40. What is the advantage of hermaphrodism?
41. What is the difference between a primary and a secondary host?
42. Name two diseases caused by parasitic flatworms.
Pseudocoelomates - Phylum Nematode (Roundworms)
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AP Biology
Origins and Diversity of Life on Earth
Reading Guide – Chapter s 31 - 33 - The Evolution of Animals
43. What animals are in the phylum nematode?
44. Where are these animals found?
45. How are nematodes structurally different from flatworms?
46. Fill in the following:
a. Symmetry:
b. Tissue Layers:
c. Body Cavity:
d. Digestive system:
e. Circulatory structures:
f.
Respiration:
g. Excretory:
h. Nervous system:
47. What movement is characteristic of nematodes?
48. Name two diseases caused by parasitic roundworms.
COELOMATES
49. List the animal phyla from Table 321.1 that are considered coelomates.
50. Give the functional consequences of each of the following statements:
a. A coelom separates the muscles of the body wall from the muscles of the gut wall:
b. The coelomic fluid moves food, wastes and gases around the body:
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AP Biology
Origins and Diversity of Life on Earth
Reading Guide – Chapter s 31 - 33 - The Evolution of Animals
c. The coelom gives space for the circulatory system:
51. How does the development of an efficient circulatory system encourage the development of a large
animal?
52. How is the development of a coelom related to the development of gonads?
53. How does the development of a coelom related to the development of complex behavior patterns?
54. All organisms that have a true coelom also exhibit what other characteristics?
55. The coelomates also exhibit the adaptation to life on land. What are some the advantages of sea
life?
56. What are some advantages to living on land?
57. What are some problems associated with life on land?
Phylum Mollusca
58. Members of phylum Mollusca include:
59. What are the three parts of the basic molluscan body plan?
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AP Biology
Origins and Diversity of Life on Earth
Reading Guide – Chapter s 31 - 33 - The Evolution of Animals
60. What part of a mollusk secretes the shell?
61. What is the radula used for?
62. What is the mantle cavity used for?
63. What structures are used by mollusks for gas exchange?
64. What type of circulatory system do most mollusks contain?
65. Define hemolymph and hemocoel.
66. How do clams obtain food?
67. What is the only class of mollusks with a closed circulatory system?
68. What is the only cephalopod that has a shell?
69. Name the four adaptations of cephalopods that make them excellent hunters.
Phylum Annelida
70. What distinguishing feature unites the members of phylum Annelida? Name some members.
71. Each segment of an annelid is divided from other segments by partitions called _______________.
72. What are setae?
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AP Biology
Origins and Diversity of Life on Earth
Reading Guide – Chapter s 31 - 33 - The Evolution of Animals
73. Describe the circulatory system of an annelid:
74. What function do nephridia perform?
75. What is the source of wastes that nephridia excrete?
76. How does gas exchange occur in Annelida?
77. Describe the two sets of muscles in an earthworm’s body and against what do they contract?
78. In what way are the movements of earthworms different from the movements of flatworms and
roundworms?
Phylum Arthropoda
79. What notable similarity do arthropods and vertebrates have in common?
80. Why have the arthropods been so successful?
81. What are the advantages of the arthropod exoskeleton?
82. What must an arthropod do before it can grow?
83. What respiratory structures are used in Arthropods?
84. How does a hemocoel differ from a coelom?
85. Describe the nervous system. What does a well developed nervous system allow for?
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AP Biology
Origins and Diversity of Life on Earth
Reading Guide – Chapter s 31 - 33 - The Evolution of Animals
86. Most insects have _________ body segments, __________ pairs of wings, and _______ pairs of
legs.
87. Give the function of the following:
a. Malphigian tubules
b. Veins
c. Trachea
d. Spiracles
88. Why are most insects much smaller than the theoretical upper limit on their size?
CHAPTER 33 – THE DEUTEROSTOMES
All deuterostomes are triploblastic, coelomates.
Phylum Echinodermata
89. What are three characteristic features of Echinodermata?
90. Define pentaradial symmetry.
91. Describe the life-style of most echinoderms.
92. Describe the water vascular system.
Phylum Chordata
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AP Biology
Origins and Diversity of Life on Earth
Reading Guide – Chapter s 31 - 33 - The Evolution of Animals
93. What four characteristics do all chordates have at some time in their life history?
94. What is the notochord? Look at Chapter 44 – what tissue layer gives rise to the notochord? What
does the notochord become in higher vertebrates?
95. What is the nerve chord? Look at Chapter 44 – what tissue layer gives rise to the nerve chord?
96. List the three clades of chordates, and the 8 different classes of vertebrates along with a common
name.
97. Describe the two groups of nonvertebrate chordates, and explain how the sea squirt might be
ancestral to vertebrates.
98. What is the vertebrate body plan? Discuss the distinguishing characteristics of vertebrates. Be
sure to give significance to each characteristic.
99. Why are vertebrates considered segmented animals?
100.
Describe the jawless fish (Agnathans) in terms of their fins, jaws, scales and skeleton.
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AP Biology
Origins and Diversity of Life on Earth
Reading Guide – Chapter s 31 - 33 - The Evolution of Animals
101.
Give two examples of jawless fishes that are still present today.
102.
Why was the development of the jaw so important? What structure is the jaw derived from?
103.
Name the advances found in the next group to evolve – Chondricthyes.
104. The lateral line system is present in all modern fishes. What is this system and what is it used
for? What did it evolve into in higher vertebrates?
105. What is the significance of the lunglike sacs in early jawed fishes? What two structures are
believed to have evolved from this structure?
106.
What derived character separates Chondricthyes from Ray-finned fishes?
107.
What is the difference between the two groups of bony fish (ray-finned and sarcopterygians)?
108.
Which fish is considered the evolutionary link to amphibians?
109.
Describe the anatomy of the lungfish.
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AP Biology
Origins and Diversity of Life on Earth
Reading Guide – Chapter s 31 - 33 - The Evolution of Animals
110.
What were the challenges of moving life to land?
111.
What is the major advance of amphibians?
112.
Although amphibians are still ties to water, why can’t they live in the sea?
113.
How do amphibians supplement gas exchange that occurs in the lungs?
114.
List three reasons why amphibians are still tied to water.
115.
What advances are seen in reptiles?
116.
What is an amniotic egg and how did it contribute to the reptiles’ existence entirely on land?
117.
What kind of fertilization is seen in reptiles?
118.
Define:
A. Amnion
B. Chorion
C. Allantois
D. Yolk sac
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AP Biology
Origins and Diversity of Life on Earth
Reading Guide – Chapter s 31 - 33 - The Evolution of Animals
119.
Which group of reptiles is no longer seen today?
120.
Which of the reptiles is more like the birds than other reptiles?
121.
What is the defining characteristic of birds?
122.
Describe two adaptations for flight seen in birds.
123.
What was the earliest known bird?
124.
Which vertebrates are endotherms? What is the significance of endothermy?
125.
Which characteristics define the mammals?
126.
What are the three modern groups of mammals?
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