Chapter 5 & 6

4. Whiskers
5. The most primitive living mammals
6. General term for a pigment cell
9. An abrupt transformation from one anatomically distinct stage (juvenile) to another (adult)
12. Bone-forming cells
15. The skin layer over the dermis that is derived from ectoderm
17. A dermal bone located under and supporting an epidermal scale
18. The skin layer that lies beneath the epidermis and is derived from mesoderm
19. The dorsal, dome-shaped bony part of a turtle shell
21. Cells specialized to secrete a product
22. The tissue lining blood and lymph vessels
24. Release of the ovum from the ovary
26. The hollow ball of cells around the internal blastocoel cavity
27. The process by which the skin forms proteins, especially keratin
29. Prereproductive individuals
31. The blastula stage in mammals
32. A diverticulum of the hindgut endoderm
34. A type of chromatophores containing red pigments
35. The skin covering the body
36. An older term for a derivative of the enamel that covers some fish scales
37. Eggs with slight amount of yolk
38. A network of loosely connected cells
39. The increase of cellular diversity
40. The act of laying eggs

1. Enlarged keratinized plates on the tips of the ungulate digits
2. Spaces within the matrix
3. An embryonic skin segment
7. The middle shaft
8. The ventral bony part of a turtle shell
10. Release of milk to a suckling
11. An older term designating a derivative of dentin that covers some fish scales
13. The female gamete
14. A joint through which little or no movement is permitted between articulated skeletal elements
16. Fibrous protein
20. Feather tracks
23. Solid mass of cells
25. Keratinized straining plates that arise from the integument in the mouth of some species of whales
28. A branched, bare bone that grows outward from skull bones on some artiodactyl species
30. hardest substance in vertebrate body, consisting almost entirely of calcium salts as apatite crystals
33. The differentiation of organs from tissues