Fig. 23-1, p.360

1. Fig. 23-1, p.360

2. Table 23-1, p.361

3. dorsal posterior ventral anterior Fig. 23-2, p.361

4. Fig. 23-3, p.363

5. placozoans sponges cnidarians flatworms rotifers mollusks annelids roundworms arthropods echinoderms chordates deuterostomes, anus forms first in embryos protostomes, mouth forms first in embryos radial ancestry, two germ layers bilateral ancestry, three germ layers no true tissues true tissues multicelled body choanoflagellates fungi Fig. 23-6, p.364

6. Fig. 23-7, p.365

7. water out glassy structural elements ameboid cell pore central cavity semifluid matrix flattened surface cells collar cell water in water in flagellum collar of microvilli nucleus Fig. 23-8, p.365

8. Fig. 23-9, p.366

9. barbs on discharged thread exposed capsule's trigger (modified cilium) lid barbed thread in capsule nematocyst (capsule at free surface of epidermal cell) Fig. 23-10, p.366

10. Fig. 23-11, p.367

11. reproductive polyp male medusa female medusa sperm ovum zygote feeding polyp one branch of a colony growth of a polyp ciliated bilateral larva Fig. 23-12, p.367

12. rudimentary brain (pair of large ganglia in head) ovary branching gut testis oviduct pharynx; protrudes onto food, then retracts into the body between feedings pair of nerve cords that have lateral branchings genital pore Fig. 23-13, p.368

13. Fig. 23-14, p.369

14. proglottids scolex A human, the definitive host, eats infected, undercooked beef, which is mainly skeletal muscle. Larvae, each with inverted scolex of future tapeworm, become encysted in intermediate host tissues (e.g., skeletal muscle). scolex attached to wall of intestine one proglottid Inside each fertilized egg, an embryonic, larval form develops. Cattle may ingest embryonated eggs or ripe proglottids, and so become intermediate hosts. Each sexually mature proglottid has female and male organs. Ripe proglottids containing fertilized eggs leave the host in feces, which may contaminate water and vegetation. Fig. 23-15, p.369

15. Fig. 23-16, p.370

16. Fig. 23-17, p.370

17. Fig. 23-18, p.371

18. Fig. 23-20, p.372

19. Fig. 23-21, p.373

20. esophagus stomach brain kidney arm jaw cuttlebone radula mantle accessory heart anus ink sac heart reproductive organ tentacle gill siphon Fig. 23-21, p.373

21. pharynx intestine eggs in uterus gonad false coelom (unlined body cavity) anus muscular body wall Fig. 23-22, p.374

22. Fig. 23-23, p.374

23. Fig. 23-24, p.375

24. chelicerae Fig. 23-25, p.376

25. Fig. 23-27, p.377

26. Fig. 23-32, p.379

27. Fig. 23-33, p.380

28. Fig. 23-34, p.381

29. Fig. 23-34, p.381