Across
- 7. upper surface of bilaterally symmetrical animals
- 9. stinging cell
- 11. outside
- 13. muscle, circulatory, excretory
- 15. lower surface of bilaterally symmetrical animals
- 17. produces both eggs and sperm in the same body
- 20. inside
- 21. sperm and egg combine inside the animal's body
- 22. middle
- 23. head end of bilateral animals where sensory organs are often located
- 24. skin, nerve
- 26. fluid-filled body cavity completely surrounded by mesoderm
- 27. body plan that tends to concentrate nervous tissue and sensory organs at the anterior end
Down
- 1. sperm and egg combine outside the animal's body
- 2. animal without a backbone
- 3. an animal without a coelom
- 4. fertilized egg cell
- 5. cnidarian body form in which the body is umbrella shaped with tentacles that hang down
- 6. organism that attaches to one place and stays there
- 8. term describing the arrangement of an animal's body
- 10. capsule holding a coiled, threadlike tube containing poison and barbs
- 12. fluid-filled body with mesoderm
- 14. animal with an endoskeleton or backbone
- 16. tail end of bilaterally symmetrical animals
- 18. digestive tract lining and organs
- 19. two-cell-layer sac with an opening at one end
- 25. fluid-filled ball of cells formed during early embryo development