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2. Resources Chapter Presentation Visual Concepts Transparencies Standardized Test Prep

3. Sponges, Cnidarians, and Ctenophores Chapter 33 Table of Contents Section 1 Porifera Section 2 Cnidaria and Ctenophora

4. Section 1 Porifera Chapter 33 Objectives • Describethe basic body plan of a sponge. • Describethe process of filter feeding in sponges. • Contrastthe processes of sexual and asexual reproduction in sponges.

5. Section 1 Porifera Chapter 33 Body Plan of Sponges • The phylum Porifera is made up of sponges. • Sponges are sessile invertebrates that have no true tissues or organs. The simplest sponges are shaped like hollow cylinders. • The body wall of a sponge is composed of two layers of cells that are separated by a jellylike substance called mesohyl. • Choanocytes in the interior layer draw water through the ostia that penetrate the body wall. The water leaves through the osculum. • The body is supported by a skeleton made of spongin, spicules, or both.

6. Section 1 Porifera Chapter 33 Sponges

7. Section 1 Porifera Chapter 33 Structure of a Sponge

8. Section 1 Porifera Chapter 33 Parts of a Sponge

9. Section 1 Porifera Chapter 33 Collar Cells

10. Section 1 Porifera Chapter 33 Feeding and Digestion in Sponges • Sponges feed by filtering small organisms and organic matter out of the water that passes through their body. This is called filter feeding. • Nutrients are distributed through the body by amoebocytes, cells which crawl about within the body wall.

11. Section 1 Porifera Chapter 33 Feeding Habits of Sponges

12. Section 1 Porifera Chapter 33 Reproduction in Sponges • Sponges can reproduce both asexually and sexually. • They reproduce asexually through: • producing buds or gemmules • regeneration of missing parts • They reproduce sexually through the joining of egg and sperm. • Most sponges are hermaphrodites, which can produce both eggs and sperm.

13. Section 1 Porifera Chapter 33 Sexual Reproduction in Sponges

14. Section 1 Porifera Chapter 33 Reproduction in Sponges

15. Section 2 Cnidaria and Ctenophora Chapter 33 Objectives • Describethe basic body plan of a cnidarian. • Summarizehow cnidarians feed. • Describethe nervous system of cnidarians. • Identifyand give examples of the four classes of cnidarians. • Describethe common characteristics of ctenophores.

16. Section 1 Porifera Chapter 33 Gemmules

17. Section 2 Cnidaria and Ctenophora Chapter 33 Body Plan of Cnidarians • Animals in the phylum Cnidaria are radially symmetrical aquatic invertebrates that are more complex than the sponges. They have tissues and a few simple organs. • The cnidairan body is either a sessile polyp or a swimming medusa. Some cnidarians alternate between both types during their life cycles. • The body of a cnidarian consists of two cell layers: • an outer epidermis • an inner gastrodermis • The layers are separated by the mesoglea. • The gastrovascular cavity has a single opening (the mouth) surrounded by tentacles.

18. Section 2 Cnidaria and Ctenophora Chapter 33 Feeding and Defense in Cnidarians • Cnidarians have cells called cnidocytes. • Each cnidocyte contains a nematocyst. • When a cnidocyte is stimulated, its nematocyst ejects a filament that can paralyze or ensnare prey. Nervous System in Cnidarians • The cnidarian nervous system is a diffuse web of interconnected nerve cells called a nerve net.

19. Section 2 Cnidaria and Ctenophora Chapter 33 Classification of Cnidarians The four classes of cnidarians are: • Class Hydrozoa • This class includes Obelia, man-o-war, and the hydra. • Hydrozoans may live as polyps, medusae, or mixed colonies. • Class Cubozoa • This class includes box jellies. • Cubozoans spend most of their lives as medusae. • Class Scyphozoa • This class includes jellyfish. • Scyphozoans spend most of their lives as medusae. • Class Anthozoa • This class includes sea anemones and corals. • Anthozoans live only as polyps.

20. Section 2 Cnidaria and Ctenophora Chapter 33 Reproduction in Obelia

21. Section 2 Cnidaria and Ctenophora Chapter 33 Movement of Hydra

22. Section 2 Cnidaria and Ctenophora Chapter 33 Reproduction in Hydras

23. Section 2 Cnidaria and Ctenophora Chapter 33 Reproduction in Aurelia

24. Section 2 Cnidaria and Ctenophora Chapter 33 Reproduction in Jellyfish

25. Section 2 Cnidaria and Ctenophora Chapter 33 Comparing Medusa and Polyp Bodies

26. Section 2 Cnidaria and Ctenophora Chapter 33 Coral Reefs

27. Section 2 Cnidaria and Ctenophora Chapter 33 Phylum Ctenophora • Animals in the phylum Ctenophora are known as ctenophores and often called comb jellies. • Ctenophores move through the water by beating the cilia that occur in eight rows on the outside of their body. • Ctenophores capture prey with a sticky substance secreted by their colloblasts. • An apical organ at one end of the body enables ctenophores to sense their orientation in the water. • Most ctenophores are hermaphroditic. • Many ctenophores have bioluminescence.

28. Section 2 Cnidaria and Ctenophora Chapter 33 Two Cnidarian Body Forms

29. Section 2 Cnidaria and Ctenophora Chapter 33 Cnidarian Body Plan

30. Section 2 Cnidaria and Ctenophora Chapter 33 Exploration of a Cnidarian

31. Section 2 Cnidaria and Ctenophora Chapter 33 Development of Cnidarian Embryo

32. Section 2 Cnidaria and Ctenophora Chapter 33 Characteristics of Cnidarians

33. Section 2 Cnidaria and Ctenophora Chapter 33 Cnidocyte

34. Section 2 Cnidaria and Ctenophora Chapter 33 Types of Cnidarians

35. Chapter 33 Standardized Test Prep Multiple Choice 1. Why are spongin and spicules important to a sponge? A. They digest food. B. They remove wastes. C. They provide support. D. They produce offspring.

36. Chapter 33 Standardized Test Prep Multiple Choice, continued 1. Why are spongin and spicules important to a sponge? A. They digest food. B. They remove wastes. C. They provide support. D. They produce offspring.

37. Chapter 33 Standardized Test Prep Multiple Choice, continued 2. Which of the following structures are involved in both feeding and sexual reproduction in sponges? F. spicules and gemmules G. amoebocytes and spongin H. gemmules and choanocytes J. choanocytes and amoebocytes

38. Chapter 33 Standardized Test Prep Multiple Choice, continued 2. Which of the following structures are involved in both feeding and sexual reproduction in sponges? F. spicules and gemmules G. amoebocytes and spongin H. gemmules and choanocytes J. choanocytes and amoebocytes

39. Chapter 33 Standardized Test Prep Multiple Choice, continued 3. Which of the following is not a characteristic of cnidarians? A. tentacles B. choanocytes C. nematocysts D. gastrovascular cavity

40. Chapter 33 Standardized Test Prep Multiple Choice, continued 3. Which of the following is not a characteristic of cnidarians? A. tentacles B. choanocytes C. nematocysts D. gastrovascular cavity

41. Chapter 33 Standardized Test Prep Multiple Choice, continued 4. What do colloblasts do? F. They produce light. G. They secrete a sticky substance. H. They draw water through sponges. J. They form medusae that live in colonies.

42. Chapter 33 Standardized Test Prep Multiple Choice, continued 4. What do colloblasts do? F. They produce light. G. They secrete a sticky substance. H. They draw water through sponges. J. They form medusae that live in colonies.

43. Chapter 33 Standardized Test Prep Multiple Choice, continued The diagram below illustrates a hydra. Study the diagram to answer the questions that follow.

44. Chapter 33 Standardized Test Prep Multiple Choice, continued 5. Identify the substance found at point 3. A. osculum B. mesoglea C. gastrodermis D. gastrovascular cavity

45. Chapter 33 Standardized Test Prep Multiple Choice, continued 5. Identify the substance found at point 3. A. osculum B. mesoglea C. gastrodermis D. gastrovascular cavity

46. Chapter 33 Standardized Test Prep Multiple Choice, continued 6. Which structure is involved in defense? F. 1 G. 2 H. 3 J. 4

47. Chapter 33 Standardized Test Prep Multiple Choice, continued 6. Which structure is involved in defense? F. 1 G. 2 H. 3 J. 4

48. Chapter 33 Standardized Test Prep Multiple Choice, continued 7. Sponge : osculum :: hydra : A. mouth B. tentacle C. nerve net D. nematocyst

49. Chapter 33 Standardized Test Prep Multiple Choice, continued 7. Sponge : osculum :: hydra : A. mouth B. tentacle C. nerve net D. nematocyst

50. Chapter 33 Standardized Test Prep Multiple Choice, continued The diagram below illustrates a medusa. Study the diagram to answer the question that follows.