1. Table of Contents Chapter Preview 11.1 What is an Animal?
11.2 Sponges and Cnidarians
11.3 Worms and Mollusks
11.4 Arthropods
11.5 Echinoderms
11.1 What is an Animal?
11.2 Sponges and Cnidarians
11.3 Worms and Mollusks
11.4 Arthropods
11.5 Echinoderms

2. Chapter 11 Preview Questions
1. Which of the following animals appeared first during Earth’s history?
a. fishes
b. mammals
c. worms
d. reptiles

3. Chapter 11 Preview Questions
1. Which of the following animals appeared first during Earth’s history?
a. fishes
b. mammals
c. worms
d. reptiles

4. Chapter 11 Preview Questions
2. Which of the following structures is NOT found in animal cells?
a. cell wall
b. cell membrane
c. mitochondria
d. nucleus

5. Chapter 11Preview Questions
2. Which of the following structures is NOT found in animal cells?
a. cell wall
b. cell membrane
c. mitochondria
d. nucleus

6. Chapter 11 Preview Questions
3. If an animal reproduces asexually, it
a. has two parent organisms.
b. undergoes conjugation.
c. is genetically identical to its offspring.
d. inherits two different sets of alleles.

7. Chapter 11 Preview Questions
3. If an animal reproduces asexually, it
a. has two parent organisms.
b. undergoes conjugation.
c. is genetically identical to its offspring.
d. inherits two different sets of alleles.

8. Chapter 11 Preview Questions
4. If an animal has specialized tissues and organs, the animal’s cells have undergone
a. photosynthesis.
b. osmosis.
c. selective breeding.
d. differentiation.

9. Chapter 11 Preview Questions
4. If an animal has specialized tissues and organs, the animal’s cells have undergone
a. photosynthesis.
b. osmosis.
c. selective breeding.
d. differentiation.

10. Use Clues to Determine Meaning
The animals called cnidarians have two different
body plans. One form looks something like a vase.
The vase-shaped body plan is called a polyp.
A polypís mouth opens at the top and its tentacles
spread out from around the mouth.
What a
polyp is
Additional information
about a polyp

11. Apply It! 1. In your own words, what is the meaning of polyp?
Sample: A polyp is a vase-shaped cnidarian.
2. What sentence contains the definition of polyp?
Sentence 3
3. What other clues help you understand the meaning of polyp?
The last sentence tells me it has a mouth that opens at the top and is
surrounded by spreading tentacles.

12. Section 11.1: What is an Animal?
How are animal bodies typically organized?
What are the four major functions of animals?
What is symmetry?
How are animals classified?

13. Structure of Animals
The cells of most animals are organized into higher levels of structure, including tissues, organs, and systems.

14. Structure of Animals
The cells of most animals are organized into higher levels of structure, including tissues, organs, and systems.

15. Classification of Animals
This branching tree shows how the major animal groups are related.

16. Section 11.2: Sponges and Cnidarians?
What are the main characteristics of sponges?
What are the main characteristics of cnidarians?

17. Sponges
Structures surrounding the central cavity of a sponge are adapted for different functions.

18. Cnidarians
Cnidarians have two basic body plans, the vase-shaped polyp and the bowl-shaped medusa.

19. Cnidarians
Cnidarians use stinging cells to capture food and defend themselves.

20. Cnidarians
The life cycle of a moon jelly has both a polyp and a medusa stage, and both sexual and asexual reproduction.

21. Section 11.3: Worms and Mollusks
What are the main characteristics of worms?
What are the main characteristics of each phylum of worms?
What are the main characteristics of mollusks?
What are eth main groups of mollusks?

22. Characteristics of Mollusks
Although they don’t look much alike at first, a snail, a clam, and a squid have the same basic body structures.

23. Characteristics of Mollusks Soft bodies Most with a hard shell
Phylum Molluska
Characteristics of Mollusks
Soft bodies
Most with a hard shell
Mantle to secrete shell and protect organs
3 Major Groups of Mollusks
Gastropods: snails and slugs
Bivalves: clams, oysters, scallops, and mussels
3. Cephalopods: Octopuses, cuttlefish, squid, and nautiluses

24. Gastropods
1. Gastropods: snails and slugs A single shell or no shell “Stomach foot”

25. Snails and Slugs
Gastropods such as this land snail have an organ called a radula, which tears and scrapes up food.

26. Bivalves
2. Bivalves: clams, oysters, scallops, and mussels Two shells Filter feeders

27. Cephalopods
Cephalopods: Octopuses, cuttlefish, squid, and nautiluses Swim by jet propulsion Complex nervous system Muscular tentacles with suckers

28. Characteristics of Worms
Biologists classify worms into three major phyla—flatworms, roundworms, and segmented worms.

29. Life Cycle of a Dog Tapeworm
This tapeworm is a parasite that lives in more that one host during its life cycle.

30. Segmented Worms
Earthworms and other segmented worms have bodies made up of many linked sections called segments.

31. Section 11.4: Arthropods
What are the general characteristics of arthropods?
What are the distinguishing structures of crustaceans, arachnids, centipedes and millipedes, and insects?

32. Characteristics of Arthropods Invertebrates Exoskeleton
Arthropods Ch 11.4
Characteristics of Arthropods
Invertebrates
Exoskeleton
Segmented bodies
“Jointed bodies”
Open circulatory system
Major Groups of Arthropods
1. Crustaceans 
2. Arachnids:  
3. Centipedes and millipedes

33. Crustaceans Crustaceans: crabs, barnacles, shrimp, crayfish
Crustaceans: crabs, barnacles, shrimp, crayfish
Two or three body sections
3 pair of appendages for chewing
5 or more pair of legs

34. Crustaceans
A crustacean is an arthropod that has two or three body sections, five or more pairs of legs, and two pairs of antennae.

35. Arachnids Arachnids: spiders, ticks, mites, and scorpions
Two body sections
8 pair of legs
no antennae

36. Insects
Phylum Arthropoda Characteristics of Insects Invertebrates Exoskeleton Three body sections (head, thorax, abdomen) One or two pair of wings Open circulatory system Six legs Communication Sound Pheromones (perfume for insects)

37. Body Structure
Insects are arthropods with three body sections, six legs, one pair of antennae, and usually one or two pairs of wings.

38. Life Cycle
An insect with complete metamorphosis has four different stages: egg, larva, pupa, and adult.

39. Life Cycle
An insect with gradual metamorphosis has no distinct larval stage. An egg hatches into a stage called a nymph, which usually looks like the adult insect without wings.

40. Defense in Insects
Flying Camouflage Exoskeleton Smell or taste Stingers

41. Centipedes and millipedes
Segmented bodies Appendages on each segment Centipedes are carnivores

42. Section 11.5: Echinoderms
What are the main characteristics of echinoderms?
What are the major groups of echinoderms?

43. Phylum Echinodermata Characteristics of Echinoderms Radial symmetry  
Characteristics of Echinoderms
Radial symmetry
Ocean dwellers
“spiney skinned”
Endoskeleton of calcium plates
Water vascular system
Tube feet

44. Characteristics of Echinoderms
Echinoderms, such as this sea star, have a water vascular system that helps them move and catch food.

45. Diversity of Echinoderms
There are four major groups of echinoderms: sea stars, brittle stars, sea urchins, and sea cucumbers. All have radial symmetry and are found in the ocean.