1. Chapter
26
Animals

2. 26 – 1 Introduction to the
Animal Kingdom
• Of all the kingdoms of organisms,
the animal kingdom is the most
diverse in appearance

3. What Is an Animal?
• Animals are Multicelular
• Animals are Eukaryotic heterotrophs
• Animal cells lack cell walls
• Animals belong to the kingdom Animalia
• The bodies of most animals contain tissues
• Ex.)epithelial, connective tissue (bone,
blood) nervous tissue
• Animals are informally grouped into 2
categories

4. Invertebrates
• Animals that don’t have a
backbone
• Over 95% percent of all animal
species are grouped into this
category

5. Vertebrates
• Animals that have a backbone

6. What Animals Do To Survive
• Animals carry out the following
essential functions:

7. 1. Feeding/Digesting

8. Intracellular digestion
• Process in which food is digested
inside cells

9. Extracellular digestion
• Process in which food is broken
down outside the cells in a
digestive tract

10. 2. Respiration (gas exchange)
Ex.) skin, gills, lungs

11. 3. Circulation

12. Open circulation
• System in which blood is not
always continued within a network
of blood vessels

13. Closed circulation
• System in which
blood is contained
within a network of
blood vessels

14. 4. Excretion

15. 5. Response

16. 6. Movement/Support

17. Hydrostatic skeletons
• Layers of
circular and
longitudinal
muscles that
enable
movement
Ex.) worms

18. Exoskeleton
• External skeleton; tough external
covering that protects and
supports the body of many
invertebrates
Ex.) insects

19. Endoskeleton
• Structural support located inside
the body
Ex.) sea stars, humans

20. 7. Reproduction
• Can be sexual or asexual

21. Hermaphrodites
• Individuals that have both male
and female reproductive organs

22. External fertilization
• Eggs are fertilized outside the
female

23. Internal fertilization
• Eggs are fertilized inside the
female

24. Oviparous
• Eggs hatch outside the mother

25. Ovoviviparous
• Eggs hatch inside the mother

27. Viviparous
• Babies are born live and get
nourishment from the mother

28. Trends in Animal Evolution
• Complex animals tend to have
high levels of cell specialization
and internal body organization,
bilateral body symmetry, a front
end or head with sense organs
and a body cavity

29. Cell Specialization and Levels of
Organization
• As animals evolved, their cells
have become specialized to carry
out different functions
• Ex.) Movement, digestion,
nervous system

30. • Large animals need greater
efficiency in body processes than
smaller animals
• Groups of specialized cells form
tissues, which join together to
form organs and organ system -
all of which work together to carry
out a variety of complex functions

31. Body Symmetry
Asymmetry – no symetry
Ex.) sponges

33. Radial symmetry
• Body plan in which body parts
repeat around the center of the
body
Ex.) jelly fish, sea star

35. Bilateral symmetry
• Body plan in which only a single
imaginary line can divide the body
into 2 equal halves
Ex.) worms, insects, chordates

37. Cephalization
• Most animals with bilateral
symmetry also have a trend
toward cephalization

38. Cephalization
• Concentration of sense organs
and nerve cells at the front of an
animals body
• Organisms with cephalization can
respond to the environment in
more sophisticated ways than can
simpler organisms

40. Body Cavity Formation
• Most animals have a body cavity which is
a fluid filled space that lies between the
digestive tract and the body wall
• A body cavity is important because it
provides a space in which internal organs
can be suspended so that they are not
pressed on by muscle or twisted out of
shape by body movements
• Body cavities also allow for specialized
regions to develop, and they provide room
for internal organs to grow and expand

41. Adaptive Radiation
• Over the course of evolution, the
appearance of new adaptations –
such as jaws and paired
appendages – has launched
adaptive radiations in chordate
groups

42. Adaptive radiation
• Rapid growth in
the diversity of
a group of
organisms

43. Convergent Evolution
• Adaptive radiations sometimes
produce species that are similar in
appearance and behavior, even
though they are not closely
related. This trend is called
convergent evolution

45. Kingdom Animalia
Major Phyla

46. Phylum Porifera (Sponges)

47. Asymetrical

48. Some specialized cells

49. Phylum Cnidaria

50. Radial Symmetry

51. Stinging Cells

52. Tentacles

53. Nerve Net

54. Two Body Forms

55. Cnidarian Lifecycle

56. Asexual Reproduction

57. Coral

58. Sea Anemones

59. Box Jellyfish

60. Portuguese Man-of-War

61. Phylum Platyhelminthes
Flatworms

62. Flattened Body, one opening

63. Bilateral Symmetry

64. Sexual or Asexual Reproduction

65. Budding

66. Some are parasites

67. Tape worm mouth parts

68. Phylum Nematoda
Roundworms

69. Round Body, tapered at both
ends, two openings

70. Bilateral symmetry

71. Heartworm

72. Ascaris

73. Trichinella

74. Elephantitus

75. Phylum Mollusca
Mollusks

76. One Shell

77. Two Shell

78. No Shells

79. Nautilus

81. Squid

82. Octopus

83. Bilateral Symmetry

84. Phylum Annelidia
Segmented Worms

86. Leech

87. Clamworm

88. Feather dusters

89. Phylum Arthropoda
Arthropods

90. Arthropod Traits
• Segmented body, jointed legs,
exoskeleton
• Bilateral symmetry
• Tissues and organs
– Open circulatory system
– Complete digestive tract
– Simple excretory organs
– Brain and nerve cords
• Sexual reproduction (separate sexes)

91. 5 Major Arthropod
Classes

92. Centipedes

93. Millipedes

94. Crustaceans

95. Crustaceans

96. Crustaceans

97. Crustaceans

98. Crustaceans

99. Insects

100. Insects

101. Insects

102. Arachnids

103. Arachnids

104. Arachnids

105. Arachnids

106. Phylum Echinodermata
Echinoderms

107. Echinodermata = Spiny Skin

108. Water Vascular System

109. Tube Feet

110. Radial Symmetry

111. Brittle Sea Star

112. Sea Star

113. Sand Dollar

114. Sea Urchin

115. Sea Cucumber

116. Sea Star Eating

117. Phylum Chordata
Chordates

118. Chordate Traits
• Dorsal notochord at some time
• Pharyngeal gill slits (or pouches)
at some time
• Dorsal hollow nerve cord at some
time
• Bilateral symmetry

119. Chordate Traits
• Tissues and organs of vertebrates
– Backbone
– Brain and nervous system
– Closed circulatory system
– Complete digestive tract
– Paired kidneys
– Gills or lungs
– Paired image forming eyes
• Sexual reproduction (separate sexes)

120. Invertebrate Chordates
2 groups

121. Tunicates

122. Lancets

123. Vertebrate Chordates
7 classes

124. 1. Agnatha

125. Lamprey

126. 2. Chondrichthyes

127. 2. Chondrichthyes

128. 2. Chondrichthyes

129. 3. Osteicthyes

130. 3. Osteicthyes

131. 3. Osteicthyes

132. Swim Bladder

133. 4. Amphibia

134. 4. Amphibia

135. 4. Amphibia

136. Two Stage Life Cycle

137. 5. Reptilia

138. 5. Reptilia

139. 5. Reptilia

140. 6. Aves

141. 6. Aves

142. 6. Aves

143. 6. Aves

144. 7. Mammalia

145. 7. Mammalia

146. 7. Mammalia

147. 7. Mammalia

148. 7. Mammalia