Across
- 3. time period were early vertebrae fossil recovered
- 7. series of cartilage joined as a backbone
- 8. gel-liked core within each vertebral disk
- 9. descendants of four-footed ancestor
- 10. vertebrates with jaws
- 13. SI for mass
- 17. produce embryo wrapped in amnion
- 20. anterior clustering of specialized sensory organs
- 23. middle layer of the long bone
- 26. SI for intensity of light
- 27. encases the brain
- 28. process of moving
- 29. encloses the notochord
- 30. separated fluid flows in the same direction
- 32. support on which lever moves
- 34. unit of work
- 35. speed in one direction
- 37. rate which an object change its velocity
- 38. organ for obtaining oxygen from water
- 39. study of light and the way it affect things
- 40. weight of the air in Earth's atmosphere
Down
- 1. slender rod develops from mesoderm
- 2. four-footed
- 4. animals with spinal column
- 5. without amnion
- 6. measurements of variables with a magnitude and direction
- 11. eel-like scavengers
- 12. form of an object
- 14. jawless fishes
- 15. uniform in motion
- 16. power to push or pull objects
- 18. unit of electrical power
- 19. unit for amount of substance
- 21. encases embryo in a protective water compartment
- 22. fluid flows in opposite direction
- 24. fins placed anteriorly
- 25. force applied to an object
- 31. fluid-filled central canal
- 33. fins located posteriorly
- 36. measure of mass per unit of volume