1. Multicellular animals can be classified based on their level of organization, symmetry, presence of body cavities, digestive system structure, and segmentation. 2. Key characteristics include whether they have tissues, bilateral or radial symmetry, acoelomate, pseudocoelomate, or eucoelomate body plans, and incomplete or complete digestive tracts. 3. The animal kingdom is divided into several phyla including porifera, cnidaria, platyhelminthes, nematoda, mollusca, annelida, arthropoda, and chordata based on these structural features.

2. Animal)
(Multicellular)

3. Animal)
collagen

4. 1. (Level
of cell organization)
2. Symmetry)
3.
Body cavity or coelom)
4.
5. Digestive tract)
6. Segmentation)

5. 1.
(Level of cell organization)
1.1
No true tissue)
1.2 True
tissue)
1.2.1 2

6. 2. Symmetry)
2.1 Asymmetry)
2.2 Radial
symmetry)
2.3
Bilateral symmetry)

7. 3.
Body cavity or coelom)
3.1
No body cavity or
acoelom) Body covering
(from ectoderm)
Acoelomate: Acoelomates such as Tissue-
filled region
flatworms lack a body cavity
(from
between the digestive tract and outer mesoderm)
body wall.
Digestive tract
(from endoderm)

8. 3.2 Pseudocoelom)
Body covering
(from ectoderm)
Muscle layer
Pseudocoelom (from
mesoderm)
Digestive tract
(from endoderm)

9. 3.3 Eucoelom
or coelom) Body covering
(from ectoderm)
Coelom
Coelomate. Coelomates such as
annelids have a true coelom, Tissue layer
a body cavity completely lining coelom
lined by tissue derived from and suspending
mesoderm. internal organs
(from mesoderm)
Digestive tract
(from endoderm)
Figure 32.8a

10. 4.
4.1
(Protostomia)
4.2 Anus Mouth
(Deuterostomia) Digestive tube
Mouth Anus
Mouth develops Anus develops
from blastopore from blastopore

11. 5.
Digestive tract)
5.1
(Incomplete digestive tract)
5.2
Complete digestive tract)

12. 6.
Segmentation)
6.1
Superficial
segmentation)
6.2

13. Animal Kingdom
Phylum Porifera
Phylum Cnidaria
3 Phylum Platyhelminthes
4 Phylum Nematoda
5 Phylum Mollusca 6
Phylum Annelida
7 Phylum Arthropoda

15. •
•
•
•
•
•

18. 3
Class
1. Class
Calcarea
2. Class
Hexactinellida
3. Class
Demospongiae

20. •
• (radial
symmetry)
•
•
Nematocyst)
•
•
Nerve net)

21. • 2
-
Polyp)
-
Medusa)

25. •
protonephridia)
•
•
•
hermaphrodite)

26. 1.Class
Turbellaria
2.Class
Trematoda
3.Class
Cestoda

27. Nemato

28. •
•
• Bilateral
symmetry)
•
Pseudocoelomate animal)
•

29. •
• Nerve
ring)
•
Longitudinal muscle)
•
•

30. 3
1.
2.
3.

32. •
•
• coelom)
•
•
•

33. 5 Class
1. Class Gastropoda
2. Class PolyPlacophora
3. Class Bivalvia
4. Class Scaphopoda
5. Class Cephalopoda

41. •
•
•

42. •
nephridia)
1
• hermaphrodite)
•
•
•

43. 1. Class
Oligochaeta
2. Class
Polychaeta
3. Class

45. •
•
• 3
•
3
•
• (Molting)

46. •
• Open
circutory sysytem)
•
• 1
1
•
•

48. Trilobita

49. Xiphosur
a

50. Crustace
a

51. Insecta

53. Arachnida

54. Chilopoda

55. Diplopoda

57. 1 2 3 4 5
6 7 8 9 1
1 1 1 1 0
1
Jigsaw

60. •
• 3
•
•
• water vascular
system)

61. •
•
Class Ophiuroidea
•

64. Class Ophiuroidea

66. Class Holothuroidea

67. Class Crinoidea

69. • notochord
amphioxus
•
•
•

70. Protochordata
• Sub-Phylum Urochordata Notochord
Notochord
• Sub-Phylum Cephalochordata Notochord
Amphioxus)
Sub-Phylum Vetebrata
• Notochord

73. Class Cyclostomata Class
Agnatha

74. Class Chondricthyes

76. Class Ostheicthyes

77. Class Amphibian

78. Class Reptilia

79. Class Aves
Feather)

80. Class Mammalia
Mammal)
Hair)